Wiring - American Radio History
Wiring
audio -video
www.americanradiohistory.com
facilities
F
OK'T1
Y¡
ADM
L±i/n:M/
POST-PRO KEEPS THEM OUT!
FUZZY AUDIO MIX WILL NOT CREATE WARM LISTENER RESPONSE
With ADM's new POST-PRO Audio Post
Production Console, you can eliminate all
Fuzzys, warm or otherwise, from your
audio mix forever.
would expect nothing less than
outstanding Audio from ADM. With over
twenty years of experience in meeting
the audio needs of the video industry,
ADM has become not merely the leader
but the standard setter.
You
Now you can have full editor/switcher
control, full manual control, or a
combination of editor/switcher or
manual control. The ADM Post -Pro
provides A/B bussing with that kind
of flexibili-}+ built in.
The Post -Pro is capable of direct interface
with virtually any editor or switcher
through a oarafllel GPI or our optional
serial interface.
LOOK WHAT WE HAVE
INCLUDED IN THE NEW
POST-PRO!
Modular design with gold card
edge connectors
8 or 12 inputs
Line inputs with adjustable gain
A/B control bus and parallel
GPI
Slidex® VCA attenuators
Optional serial interface
Dual monitoring with pre -selection
Cue bus
4 large VU meters
"Invert" switch on each control bus permits fingertip cross -fades
Continuously variable 3 -band EQ with HP/LP filter
2 master outputs
e
For more
information, contact:
ADM
Circle (1) on Reply Card
ADM Technology, Inc.
1626 E. Big Beaver Road, Troy, Michigan 48084
Phone: (313) 524-2100
TLX 23-1114
www.americanradiohistory.com
We know that in the television industry,
dependability
is absolutely essential.
With ADM's exclusive five year warranty
on parts and labor, you know that when
you go "on line"... you'll stay "on line"
The Post -Pro is designed to give you
audio quality comparable to video.
Always an important consideration, with
stereo it becomes essential. Priced from
$9,500, the Post -Pro is solid quality and
solid value that means increased
flexibility, productivity and profits.
Mobile Satellite News Systems
The Second
Generation
At the 1986 NAB Show in Dallas, Midwest
ushered in the SECOND GENERATION of
Mobile Satellite News Systems, the S-18...
featuring the new Vertex 1.8M, Dual
Reflector, Off-set Ku Antenna, specifically
designed for this new service.
At the 1986 RTNDA Show in Salt Lake City,
yet another Midwest innovation, the S-23,
was introduced, featuring a 2.6M version of
the Vertex Antenna, with 50 dbi Gain and
35dó of Cross Pollar Isolation.
For more information on this remarkable
new antenna technology, Midwest's modular
TNT Power Amplifier Systems, and other
SECOND GENERATION innovations call us
at 800-543-1584.
S23
Cincinnati, OH
Toledo, OH
Grand Rapids, MI Nashville, TN
Kansas City, KS
Roanoke, VA
606331-8990
419-382-6860
616-796-5238
615-255-2801
913-469-6810
703-980-2584
Columbus, OH
614-846-5552
Pittsburgh, PA
412-364-6780
Louisville, KY
502-491-2888
Knoxville, TN
Atlanta. GA
Charlotte, NC
615-687-9515
404-875-3753
704-399-6336
Dayton
Indianapolis, IN
317-872-2327
Lexington, KY
Bristol, TN
615-968-2289
Norfolk, VA
804-853-2600
Raleigh, N.C.
Detroit, MI
313-689-9730
Charleston, WV
304-768-1252
St. Louis, MO
Richmond, VA
804-262-5788
OH
513-435-3246
Cleveland, OH
216-447-9745
606-277-4994
314-569-2240
Washington. D.C. Tampa, FL
301-577-4963
813-:-::.-9308
Baltimore, MD
301-665-9323
Orlando, FI
306-898-1885
New Orleans, LA
919-850-9811
Miami, FL
305-592-5355
Greenville, S.C.
Jacksonville, FL
Seattle, WA
803-226-9259
904-642-8368
206-232-3550
504-542-5040
www.americanradiohistory.com
MIDitiESf
Communications Corp.
One Sperti Drive
Edgewood, KY 41017
Circle
(3) on Reply Card
i
Contents
September 1986
Volume 28
Number 9
I
4Q
BRODCST
//
4
46-
6 64
50 Q
600Q
STEREO TV TAKES OFF:
Stereo audio for television is the driving force behind facility improvement efforts at hundreds of TV stations and production
houses. In this issue, we examine some of the primary considerations when planning an audio -system overhaul.
22 Wired for Stereo
By David L. Bytheway, Robert Bosch
Page 22
problem associated with stereo television is
routing audio signals throughout the facility.
A critical
36 Planning for TV Stereo
By Douglas Dickey, Solid State Logic
REPLACE MASTER
CONTROL CONSOLE
The specification and installation of a new audio console
is one of the most exciting and difficult tasks facing a
facility when making the move to stereo.
REPLACE PRODUCTION
CONSOLE
54
CONVERT
DISTRIBUTION SYSTEM
The Real World of Stereo TV
By Dennis Ciapura, Teknimax
Planning a move to stereo operation often involves as
much financial planning as technical planning.
1
1
CONVERT VTRs
t
I
AUDIO -VIDEO CONTROL EQUIPMENT:
To keep pace in today's marketplace, facility improvement must
be an on -going effort. This month we examine various aspects
of keeping current with broadcast technology.
Page 54
62 Linear Keying in Video Production
By Tom Goldberg, Ampex
New keying technology is providing users with effects
that were previously impossible.
74 Wiring an Audio-Video Production Facility
By Edgar Lee Howard, WOSU-TV
The wiring of a radio or TV facility is one of the most
complex and important jobs faced by the broadcast
engineer.
MICROPHONES FOR BROADCASTING:
92 Microphones, From the Inside
Out
By Tim Schneckloth, Shure Brothers
104 Planning Wireless Microphone Systems
By H.Y. Miyahira and Donald A. Kutz, HM Electronics
Page 62
SHOW PREVIEWS:
ON THE COVER
Without a doubt, stereo television is a smash-
ing success. Competition among stations
has resulted in strong pressures on mono
facilities within stereo markets to make
the move as quickly as possible. Our
cover this month illustrates some of the
primary elements of stereo programming: source origination and programquality monitoring equipment. The
bar graph display in the lower center
of the photograph shows a 10 -parameter aural modulation monitor
readout. The waveform display
above the bar graph is a stereo
audio monitor. (Photo courtesy
of Tektronix.)
2
Broadcast Engineering
120
SBE National Convention
By Brad Dick, radio technical editor
122
SMPTE Fall Convention
By Carl Bentz, TV technical editor
DEPARTMENTS
4 News
6 Editorial
8 FCC Update
10 Strictly TV
12 re: Radio
14 Satellite Technology
16 Circuits
September 1986
www.americanradiohistory.com
18
Troubleshooting
20 Management for Engineers
130 SBE Update
134 Station -to -Station
136 People
139 Business
142 New Products
HITACHI INVENTS
THE FIRST 1" VTR
THAT WATCHES ITSELF
SO YOU DON'T HAVE 1a.
fast/slcw ma=ic-i range
-time
that p_ny des
reverse and fìieid/frame
still no -ion. ?Its programmable time compression -tp to 2Q%, with
0.1% accuracy.
A unique, conoeaLed foldout control panel grams edi=
ing functions and separates elk
controls from the main control
panel.
In shor_, it's the LL-i _Hare 1"
for networks, aff_lirte_s or teleproducticn compas es. Don't
consider your next V' purchase w.thout looking into
it. Contact Hitaca_ Jenshi
Amerka, L -d 3a adzast
and Prcfessicnial iEisian,
175 Crossways Park West,
The revcL tionary Hitach_
HR -230 VTR has the
mcst advanced real-time,
set diagr-oe_3c capabi_ities
ever perfected.
In either the recorc or
playback mace, a computer;'
inside the HR-230 mcnitors
49 afferent perforn.arce paramAnd then
eters secorc 3v
stcres this in=ormatio 1 within
the memory for recall at a later
tine-not -ust with numbers
and symbo s, but in w rds.
This means no more errors
slip oy when2..-our operator islet
there. And :here's no nore need
for hit -or-Hiss spct checking.
The Hitachi HR -23] has a
urtcue gtick-threadir_g tape
path, incorn_ rating retracting entrance and exit guides,
main erase head, as well as
a scanner ai= system _hat
protects ta».
=t recues a 30-secoid segment in 3.5 seconds lt has a
.
Woodbury. NY 11751 516)
921-7200 or (i'C0) G
.E....r;.....
751.0.
Hitachi Lenslh, Ltd. (lanada).
65 Telford Drive. Scarbor-
ough, Ontario Mlß 2GE.
(416)
299-39L.
Hitachi
Circle
(4) on
Reply Card
www.americanradiohistory.com
News!
extends
exhibit hours
Committee calls
for NAB '87 papers
Exhibits of broadcast equipment at the
1987 NAB Convention will open Saturday morning rather than Sunday as in
the past. This change is in response to
recommendations of NAB's Exhibitor
Once again it is time to begin preparation for the 41st annual Broadcast
Engineering Conference, which is held
each year in conjunction with the NAB
Convention.
The conference provides an opportunity for broadcasters and manufacturers to
present papers on broadcasting equipment, systems and techniques that would
be of interest to broadcast engineers and
NAB
Advisory Committee.
Also, the 65th convention will close
with dinner and entertainment Tuesday
evening. It formerly ended with a
Wednesday brunch and entertainment.
The convention will be held March 28 to
31, at the Dallas Convention Center.
The Saturday opening and expansion
to four days will eliminate Saturday
setup overtime costs and provide attendees additional time to visit the exhibit halls. The committee also agreed to
provide additional security and bus
transportation for the exhibitors which,
along with other improvements, requires
an increase in the per -square-foot exhibit
hall cost from $16 to $17 on the upper
level and from $14 to $15 on the lower
level.
NAB serves a membership of more
than 4,700 radio and 900 TV stations, including all the major networks.
BRoaDcasT
erlGlfl@ERIiiG
EDITORIAL
Jerry Whitaker, Editor
Carl Bentz, TV Technical Editor
Brad Dick, Radio Technical Editor
Dan Torchia, Group Managing Editor
Paula Janicke, Associate Editor
Dawn Hightower, Associate Editor
Pat Wanton, Directory Editor
ART
Todd Meyers, Graphic Designer
EDITORIAL CONSULTANTS
Fred Ampel, Audio
Miguel Chivite, International
Nils Conrad Persson, Electronics
Tom Cook, Video
Mel Lambert, Professional Audio
BUSINESS
Cameron Bishop, Group Vice President
Duane N. Hefner, Publisher
Stephanie Fagan, Promotions Manager
Cynthia Sedler, Promotions Coordinator
Dee Unger, Advertising Supervisor
Mary Birnbaum, Advertising Coordinator
Advertising sales offices listed in classified section.
ADMINISTRATION
Hancock, President
John C. Arnst, Circulation Director
JoAnn DeSmet, Circulation Manager
Kevin Callahan, Art Director
Dee Manies, Reader Correspondent
R. J.
4
Broadcast Engineering
technicians.
Papers from associate members that
relate to notable improvements in broadcast engineering technology, systems
design or techniques that do not directly
relate to a specific product also are invited. Papers are being sought specifically from equipment users and associate
members involved in the latest broadcast
technology.
The NAB Broadcast Engineering Conference Committee will meet in October
to select the papers to be presented.
Anyone interested in presenting a paper
should send a 1 -page abstract on the proposed subject by Oct. 10 to: Engineering
Conference Committee, Science and
Technology Department,
National
Association of Broadcasters, 1771 N. St.
N,W., Washington, DC 20036.
All papers accepted for presentation
must be completed with artwork and
received at NAB by Feb. 13, in order to
be included in the Conference Proceedings, which will be made available at
the convention. For more information
call 202-429-5346.
SMPTE forms
ad hoc HDTV group
The Society of Motion Picture and Television Engineers (SMPTE) has formed an
ad hoc group on high -definition studio
systems to document the specification
for the current 1,125 line/60 field
high-definition TV system.
The SMPTE's engineering effort to
prepare a series of documents on the
HDTV system is being undertaken in
response to requests from the Advanced
Television Systems Committee (ATSC),
the Canadian Broadcasting Corporation
and the CTV Television Network in
Canada.
The purpose of the group is to ensure
Continued on page 160
Editorial and advertising correspondence should be addressed to: P.O. Box 12901, Overland Park, KS
66212-9981 (a suburb of Kansas City, MO); (913) 888-4664. Telex: 42-4156 Intertec OLPK. Circulation correspondence should be sent to the above address, under P.O. Box 12937.
TECHNICAL CONSULTANTS
Eric Neil Angevine, Broadcast Acoustics
John H. Battison, Antennas/Radiation
Blair Benson, TV Technology
Dennis Ciapura, Radio Technology
Dane E. Ericksen, Systems Design
Howard T. Head, FCC Rules
Wallace Johnson, FCC/Bdct. Engineering
John Kean, Subcarrier Technology
Donald L. Markley, Transmission Facilities
Harry C. Martin, Legal
Robert J. Nissen, Studio/Communications
Hugh R. Paul, International Engineering
Art Schneider, A.C.E., Post-production
Elmer Smalling ill, Cable/Satellite Systems
Vincent Wasilewski, Communications Law
SUBSCRIPTIONS: BROADCAST ENGINEERING is
mailed free to qualified persons within the United States
and
Canada in occupations described above. Non qualified persons may subscribe at the following rates:
United States and Canada; one year, $25.00. Qualified
and non -qualified persons in all other countries; oneyear, $30.00 (surface mail); $108.00 (air mail). Back issue
rates, $5, except for the Buyers' Guide/Spec Book,
which is $20. Rates include postage. Adjustments
necessitated by subscription termination at single copy
rate. Allow 6-8 weeks for new subscriptions or for
change of address. Second class postage paid at
Shawnee Mission, KS.
BROADCAST ENGINEERING, Volume 28, No. 9
(USPS 338-130) is published monthly (except in the fall,
when two issues are published) by Intertec Publishing
Corporation, 9221 Quivira Road, P.O. Box 12901,
Overland Park, KS 66212. Second Class Postage paid at
Shawnee Mission, KS and additional mailing offices.
POSTMASTER: Send address changes to BROADCAST
ENGINEERING, P.O. Box 12983, Overland Park, KS
66212.
MEMBER ORGANIZATIONS
Acoustical Society of America
Society of Broadcast Engineers
Member,
Association of Business Publishers
Member,
Business Publications
Audit of Circulation
MP
VBPA
Photocopy rights: Permission to ohotocopy for internal
or personal use is granted by Intertec Publishing Corporation for libraries and others registered with
Copyright Clearance Center (CCC), provided the base fee
of $2.00 per copy of article is paid directly to CCC, 21
Congress St., Salem, MA 01970. Special requests should
be addressed to Cameron Bishop, group vice president.
ISSN 0007 1794 $2.00 + $0.00.
©1986. All rights reserved.
BROADCAST ENGINEERING
is edited for corporate
management, engineers/technicians and other station
management personnel at commercial and educational
radio and TV stations, teleproduction studios, recording
studios, CATV and CCTV facilities and government
agencies. Qualified persons include consulting engineers
and dealer/distributors of broadcast equipment.
September 1986
www.americanradiohistory.com
Advertising offices listed on page 164.
NiINTFRTE
It's the reason why
these three new Leitch test generators
are tailored to your needs.
These three new test generators may
look alike. But the software inside tells
another story. Before they were designed, we
sat down with transmitter, studio and transmission people to find out what they needed
and wanted.
With these new Leitch 2500 NTSC test
generators, you get digital generation for
accuracy and stability. The Transmitter and
Transmission generators deliver up to 60
signals while the Studio generator provides 56
different signals. All with 10 bit precision.
Upgradeable EPROMs allow you to have
the unit adapted to meet new signal requirements. And you get Leitch ease of operation.
If you want further information, just
-write or call. You'll find were not only good
listeners, we're good providers.
ii
241
Leitch Video International lac.. IO Dyas Road, Don Mills. Ontario, Canada M3B 1V5. Tel.: (416) 445-9640 or 1-800.87-0233. Telex: 06 986 4342
Leitch Video of America. Inc. S >K Greenbrier Circle. Chesapeake. VA. U.S.A. 23320, Tel.: (804) 424-7920 or 1-800-231-9673. Telex: 710 882
Circle (5) on Reply Card
www.americanradiohistory.com
IEditorkd
I
In case you've been sleeping for the past couple of years, you might not have noticed
It's for you
6
the skyrocketing cost of your telephone service. You wouldn't know that the Department of Justice, under the guise of antitrust protection, forced the breakup of AT&T.
We were told that reduced telephone rates would result.
When it became obvious that the government was going to win no matter what the
effect on the consumer might be, the FCC began restructuring the rates charged by
the telephone companies. Remember now, the whole idea of the suit was to avoid an
antitrust situation, which supposedly artificially inflates consumer costs. Under the
FCC's restructuring process, new and improved (lower?) rates were to take effect.
Well, rise and shine and take a look at your phone bill. Your telephone costs have
not only increased, but increased faster than it was thought possible. And even worse,
the rates continue to increase.
In April 1985, the new FCC-approved telephone rates went into effect. What followed can only be described as a disaster for broadcasters. A 1985 survey conducted
by the NAB showed widely varying costs for broadcast station services. The first NAB
survey showed that the average increase in telephone charges was 390%. Some stations experienced increases of more than 2,000%. How much did your telephone
costs go up?
Although the NAB conducted surveys and participated in rulemaking proceedings
before the FCC, little relief for the broadcaster was forthcoming. Once the decision to
break up Ma Bell was made, broadcasters (and most of the other telephone consumers in the United States) were doomed to higher rates.
So what has this got to do with today's conditions?
For one thing, the station engineers are going to have to learn to wear another
hat-that of the telephone specialist. In stations throughout the country, station
engineers are finding themselves involved in the selection and even installation and
maintenance of in-house telephone systems. Broadcast engineers used to be able to
rely on a friendly telephone installer to help them with the unique telephone needs of
broadcast stations. No more.
Many people now installing telephone equipment know little about (or have no appreciation for) the special needs of radio and TV stations. You may have also noticed
that the installers seem younger than before. In AT&T's reorganization, many of the
old-timers you came to depend upon have retired. The new installers often don't have
the many years of experience that were so helpful to the broadcaster.
This change means that station engineers are required to become knowledgeable
about another type of technology. Management may take it for granted that because
the telephone equipment looks much like other devices in the station, the engineer
should be able to maintain it. For those stations that purchase their own telephone
equipment, maintenance by the station engineer may even be a requirement.
These changes mean that you must make the effort to become familar with the
changing nature of telecommunications. Learn all you can about telephone systems
so you can help protect your station's interests when the time comes to purchase or
lease a telephone system. Don't be afraid of the technology. After all, you learned to
switch from tubes to transistors to ICs to computers with digital audio and video. You
can also learn how your station's telephone system works.
The broadcast engineer can play a key role in helping the station cope with the increased costs of telephone services. Learn the technology. Modern telephone systems
are complex, yet rely on devices common throughout most stations. Don't be intimidated by a new telephone system. Computer-controlled or relay-activated, it is
just another piece of equipment in the engineer's station. Although you may never
have to repair the system, a thorough knowledge of how it works can greatly benefit
your station.
There may be a few instances in which the breakup of Ma Bell actually reduced station telephone costs. If so, we'd like to hear about them. The stories repeated in
engineering and management meetings usually tell of reduced service at higher
prices. It seems a good example of the old adage of getting the short end of the stick.
For the broadcaster, it's even worse. You might even say that the broadcasters have
been clubbed by the courts and the FCC with that stick.
I =r=))))1
Broadcast Engineering September 1986
www.americanradiohistory.com
The Abekas A42
Video Slide Projector
With the introduction of the A42
Video Slide Projector, we revolutionized the still store business.
Now, three years and 300 units later,
we let our customers tell the success
story of the A42. The widespread
use of the A42 by networks and TV
stations across the country has set
a new standard for still stores in
the television industry.
The overwhelming acceptance of the A42 was no accident. It
was a pioneering effort from Abekas
that did the job-for the right price.
This small but powerful
system is the answer for those
seeking upward mobility. The A42
comes in single or dual -channel
configuration. Winchester -style
hard disks provide an on-line
storage capacity of up to 1050 frames/
2100 fields. A digital 1/4" cartridge
tape provides easy-to -handle,
cost-effective, off-line storage.
An optional library system gives
the user simple yet sophisticated
file management for up to 10,000
on-line slides.
Discover the reasons behind
the ever-growing list of our cus-
Circle (6) on Reply Card
www.americanradiohistory.com
tomers. Find out from them why the
A42 can't be topped when it comes
to outstanding reliability and price/
performance. For details and a
complete A42 customer list, contact
us at: Abekas Video Systems, Inc.,
353A Vintage Park Drive, Foster
City, CA 94404. (415) 571-1711.
Abdc1S
VMeo Systems. Inc
Now Anything is Possible
FCC update
I
Must -carry in effect
By
Harry
C.
Martin
In response to broadcast industry and
congressional pressure, the FCC has
adopted new CATV must -carry rules.
The previous mandatory carriage rules
were held unconstitutional in July 1985.
Under the 2 -part rules, cable systems
will be required to provide new subscribers with (A/B) input selector switches
for receiving off -air signals at no cost. Existing subscribers could be charged a fee
for the switch. A cable operator must offer to supply and install a switch for each
separate cable hookup and inform the
subscriber that an antenna may be needed for off -air reception.
The second part of the program
establishes new mandatory carriage
requirements for a period of five years.
Cable systems having 20 or fewer usable
activated channels are not required to
carry any local commercial stations.
Systems with more than 20, but fewer
than 27, activated channels are required
to devote no more than seven channels to
qualified commercial broadcast signals.
Systems with 27 or more channels must
devote up to 25% of their capacity to
mandatory carriage. All systems must
carry at least one non-commercial station, while those with 34 or more channels must carry at least two.
To qualify for carriage, a station must
be licensed to a community that is within
50 miles of the cable community. The
station must show that it has a 2%
average share of total viewing hours and
a net weekly circulation of 5% in non cable homes where the cable system is
located. New commercial stations will be
exempt from this requirement and will
be carried regardless of market share for
their first year of operation.
A cable system will not be required to
carry more than one station affiliated
with the same commercial network.
Also, systems will not be required to
carry an otherwise qualified station that
would be considered a distant signal, for
copyright purposes.
Additionally, where the number of
qualified stations exceeds the maximum
number of channels that a cable system
is required to devote to must -carry
signals, the cable system has full discretion to select the stations it will cover.
Modification rules reviewed
The FCC has begun a review of its rules
Martin is a partner with the legal firm of Reddy, Begley
& Martin, Washington, DC.
8
hearings. The commission believes the
amended rules will benefit public interest
by expediting expanded FM service.
concerning modifications of transmission
systems. The proposal, which would affect all 10,000 broadcast licensees, would
allow stations to make minor electrical
and mechanical modifications to their
authorized transmitters without having
to first obtain commission approval.
Under present rules, certain transmitter modifications can be made without
prior approval. However, if a modification could cause the equipment to
operate beyond tolerances specified by
the commission, then prior approval is
required. The commission now views
these rules as too narrow.
The proposal would require licensees
who wish to modify or improve their
transmitters to make the appropriate
tests to ensure that the modified equipment is operating within commission specified parameters. Therefore, it would
be up to each station to ensure that its
equipment will transmit signals within
the proper bandwidth and that excessive
emissions will be suppressed. To help
minimize harmful interference, the commission proposes that broadcasters
should take measurements and keep
them for as long as the modified equipment is being used.
The proposed rules would not permit
AM stations to install stereo without prior
approval. The commission believes that
deregulation of AM stereo, which is still
in its infancy, would be premature.
New rules on FM upgrades
operators are now allowed to
upgrade their facilities on their existing
or adjacent frequencies without having
to face competing applications. However, the rule, which became effective
on June 5, applies only to existing and
newly instituted rulemaking proceedings.
Although previous rules encouraged
the upgrade of FM stations, upgrades
generally occurred only when at least
one other equivalent higher class of
channel could be found to meet the interests of other parties. If no channel was
available, FM stations would not seek an
upgrade because they risked losing their
existing authorizations in comparative
FM
Broadcast Engineering September 1986
www.americanradiohistory.com
FM technical rules reviewed
This past spring the commission began
a review of its FM technical rules to
clarify and correct inconsistencies and to
simplify procedures that have become
overly complicated as a result of Docket
80-90. In that docket, the FM rules were
amended to make room for more stations in the FM band by increasing the
number of station classes from three to
six and by changing mileage separation
requirements.
The commission is now preparing to
replace the minimum power and antenna height restrictions with equations that
would represent a continuous range of
facility options. The existing rules present a list of the minimum and maximum
power and antenna heights permitted for
each class of station.
There are certain combinations of
power and antenna heights that do not
conform to any defined station class.
Because Docket 80-90 granted existing
stations three years to expand their
facilities to meet the minimum requirements of the docket's classification
scheme, the commission stated that
review of allocation requirements is
necessary to provide guidance to those
stations subject to reclassification on
March
1,
1987.
The commission recognized that its
proposal could have a negative impact
on the 49 stations currently in the process of expanding their facilities to avoid
the reclassification deadline. However,
the impact would be minimal because affected stations will retain the classifications they originally anticipated.
The commission also proposes to allow
higher classes of stations on the Class A
channels, as long as such upgrades
would be consistent with the permitted
distance separation rules. Although the
commission presently allows Class A stations to be licensed on all commercial
channels, it does not allow the use of
designated Class A channels for higher
classes of stations.
Finally, the commission has proposed
that an FM station's class be determined
by the location of the city of license
rather than the location of its transmitter. The current rules are not consistent
as to whether transmitter site or city of
license determines classification.
:4)))1
)))1
TH DUBN:R
FAM LY
CEG -2
TEXTA
20-K
CBG-2: The head of the family. This Emmy award -winning
graphics system combines the power of 3-D modeling with realtime animation playback, NTSC video painting and two channels
of multi -featured character generation. A breakthrough product
which has spawned a full spectrum of compatible products to meet
the needs of every video user.
TEXTA: Bridges the gap between character generator3 and
expensive animation systems. High qua'ity graphics in medium
priced single and dual channel configurations. Compctible
the CBG for exchanging advanced animations, graphics, and fonts
20-K and 10-K: Low cost, full -function, real-time character
generators featuring 16 million colors, linear keying, anti-xliasec
fonts, multiple effects and much, much more. And... animations
or graphics created on a CBG or Texta can be played bock
DPS-1: A true NTSC video frame grabber/painting system.
Incredibly advanced features for an unbelievably low pricm. Compatible with the "3rd plane" of the CBG-2LX.
Watch for new additions to the Dubner family: Multi -channel sti_1
store, more in the low price "K" series, dual channel options anc
exciting new products.
The Dubner Family of products. Compatible. Affordable. The Be ;t.
10-K
DPS-1
r local Grass Valley Group
re, contac
r spacious nev+ facilit
all Dubner
DUBNER
6 Forest Avenue, Paramus, Ií.). 07652 gal; 845-8900
Croup Company
www.americanradiohistory.com
Strictly TV!
Advanced TV displays
the big screen
By Ben Crutchfield
0
ne of the main objectives of advanced TV systems is the capability of
displaying a larger-screen picture. The
current system looks good on screens up
to 30 inches diagonal and can look impressive on a 19 -inch or smaller set with
good filtering. On a large projection
screen the weaknesses begin to
show-scanning lines are noticeable, and
resolution looks soft.
At typical viewing distances, the TV
picture often covers less than 10° of the
eye's field of view. A 19 -inch diagonal
picture is about 11 inches high. At about
61/2 feet, the picture covers a vertical
angle of about 8°. One of the people who
has studied viewer perceptions and preferences is Dr. William Glenn, director of
the New York Institute of Technology research into advanced television. Glenn
notes that viewers will typically choose a
viewing distance of about 7x picture
height for television and about 3.5x the
picture height for film or high -definition
TV systems.
The viewer tends to choose these distances because of the eye's response to
the resolution of the picture. Sensitivity
to a static image actually increases with
resolution up to a point and then
decreases. Within the field of view, the
eye has its best resolution in the central
1%. As a result viewers tend to back
away from a picture in order to get as
much in that small area as possible. The
viewer stops backing away when detail
Crutchfield Is project director for the Advanced TV
Terrestrial Broadcast Project, a joint project of NAB
and the Association of Maximum Service Telecasters.
becomes too small for the eye to resolve.
The viewer subconsciously maximizes
the amount of information.
As image resolution increases, the
viewer tends to move closer, settling at
the optimum point for the improved image. For 35mm motion picture film and
HDTV systems designed to equal 35mm
film, this point is about 3.5x the picture
height. Halving the distance to the
screen doubles the effective image
height and width; the image area is then
four times as large.
In his work, Glenn analyzed several
systems and has determined the relative
image size that could be achieved for the
same resolution in the eye of the viewer
(see Figure 1). Currently the smallest is
NTSC. Second is NTSC with improvements such as progressive scanning and
revised derivation and processing of
luminance and chrominance information, including removal of cross -color
and cross -luminance.
The next step is to a multiplexed
analog component (MAC) system-in this
case, a wide -MAC system. Finally, the
largest frame is that which can be
achieved with a high-definition system
such as Glenn is developing or the one
developed by NHK in Japan.
Resolution is neither a simple concept
nor is it the only aspect of advanced TV
systems. In general, the eye is more sen-
NORMAL NTSC
IMPROVED NTSC
IMPROVED ENHANCED TV
sitive to fine detail in static rather than
moving images. The decrease in sensitivity is not directly related to speed of
movement; sensitivity actually increases
with speed, then drops off. The eye also
is more sensitive to fine detail in
luminance information than in color.
The system on which Glenn is working
is interesting in a number of ways. At the
current stage, the system uses two channels, one of which is an improved but fully compatible NTSC channel. This channel may be transmitted and received
with existing equipment. The second
channel, less than 6MHz wide, carries
detail information and has no particular
relationship to the first.
The camera for the system is a 3 -tube,
525-line (interlaced) color camera with a
component output. In addition, the optical system has an output for a fourth,
high-resolution tube that progressively
scans 1,050 (2x525) lines at 15 frames
per second.
The progressively scanned, low frame rate signal obtains high -resolution information. The 525 -line, interlaced signal is
not as good for fine detail but, because of
the higher frame rate, provides luminance information on moving parts of
the picture, as well as most of the color.
The NTSC part of the system includes
several improvements, two of which
would help existing receivers:
Midrange detail (200- to 500-line
range) is extracted from the progressively scanned tube output, converted
to interlace and mixed with the NTSC
signal. Low frequency (0-200 lines) information, more sensitive to motion
and less to detail, is derived from the
NTSC section of the camera, and is updated at the 60-field rate.
Motion is temporally enhanced at the
transmitter end by increasing the frequency-dependent gain. This compensates for loss in contrast due to camera tube target integration.
Color and luminance are processed so
that a frame comb in the receiver
removes cross -color
and cross -
luminance artifacts without limiting
the chroma bandwidth or leaving gaps
in the luminance spectrum.
The system, still under development,
was demonstrated at the 1986 NAB Convention in Dallas.
IMPROVED HDTV
Editor's note: This article concludes a 3 -part series
Figure
10
prepared by Ben Crutchfield.
1
Broadcast Engineering
September 1986
www.americanradiohistory.com
I
:T4))j1
The world's first, ,j14/:
unidirectional surfacemounted condenser mic.
Clean and simple.
No carpet strips or plastic baffles
needed. Until now, all surface mounted mics have been
omnidirectional. Trying to add
directionality has required
a lot of busy work. The new SM91 brings the big
advantages of unidirectionality to boundary effect
microphones by incorporating a condenser cartridge
with a half-cardioid pattern that isolates the speaker
from surrounding noises.
The new smoothie. The sleek SM91 delivers wide band, smooth response throughout the audio spectrum, while greatly reducing the problems of feedback, low -frequency noise and phase cancellation.
Low visibility, high versatility. The SM91 is an excellent mic for news sets and talk shows. It also does
a great job of isolating panelists or newscasters in
multi -microphone applications.
And it's the ideal mic for
game shows.
A preamp ahead of its time.
The ultra -low noise preamplifier provides switch -selectable flat or low-cut response,
excellent signal-to-noise ratio and a high output
clipping level. A low -frequency cutoff filter minimizes low -end rumble-especially on large surfaces.
If you're going omni. Our new SM90 is identical in
appearance to the SM91 and just as rugged.
For more information or a demonstration, call or write
Shure Brothers, Inc.,
222 Hartrey Ave.,
SHINEvanston, IL 60202.
(312) 866-2553.
BREAKING SOUND BARRIERS
Circle (8) Cr Reply Card
www.americanradiohistory.com
gE
re: Radio
Learning the basics
By John Battison
Last month,
we discussed some of the
basics of broadcast engineering. Because
of the number of questions that have
been raised on antenna units (ATU), let's
take a close look at what they are and
how they are used.
Figure 1 depicts a typical tee network
that might be used in an ATU. This
discussion will consider only tee networks. Even though the L network
design uses fewer components, it is difficult to apply to directional antenna
systems. The tee network, on the other
hand, is capable of being used with most
antenna designs and, with a little study,
most engineers can understand the tee
Then any adjustments would be
made in the reactive component. In this
case, you would add a small coil to
reactance.
cancel the
If the reactance had been +j, normal
practice would dictate using a small coil
in series with a capacitor that would then
be adjusted to cancel excess +j.
5011.
-j
network.
x,
Why are they needed?
Why do you need an ATU? It would
certainly seem more straightforward to
simply connect the transmitter to the
antenna. After all, isn't that how it's done
in FM?
Unfortunately, AM systems are a bit
more complex than most FM installations, so you usually have to provide
some matching system between the
transmitter and antenna. Although some
AM systems may not have any network,
most installations have some form of a
matching network.
A non -directional shunt -fed system is
one example in which a network might
not be required. If the shunt feed line happens to be adjusted so that the antenna
resistance matches the transmission line
impedance, then only a small amount of
reactance, capacitive or inductive, may
be required to drop the j component.
xz
ZN,(LINE IMPEDANCE)
70 *
10
O
ZI -Z2 = -Z3
=,/70x61
= j65.3511
Assume you have an antenna impedance of 5111 with a -j432 reactance
and a feed line with a 5011 impedance.
It's usually possible to tune the transmitter output so it will properly operate in
this configuration. The capacitive reactance can be eliminated by a simple coil
placed in series with the shunt feed line.
The coil is adjusted to approximately
+j4311, which takes care of any stray
reactances within the feed system. An
antenna impedance of 5111 is used and
the antenna drive current is adjusted for
the correct power.
In actual practice, most engineers
would readjust the shunt feed position on
the tower so that the resistance becomes
Battison, BE's consultant on antennas and radiation,
owns a radio engineering consulting company in Columbus, OH.
12
Broadcast Engineering
Thus the reactance of each leg is
with both series legs being +j
and the shunt leg being -j.
The antenna leg already has +j4011 of
reactance from the antenna itself. This
means you need only +j25.35í1(65.35
40.0) of reactance in the series leg X2 .
This is because j components in series
add, just like series resistances.
You may come across tee networks
with series legs (X, and X2) that use
capacitors in series with inductances.
This configuration is an indication that
the sign of the series reactance is
negative. In this case, the inductances
are used in series with the capacitors to
form the familiar variable capacitor by
tapping down the coil to cancel out some
reactance.
Sometimes a pure capacitive reactance
in the shunt leg provides better antenna
matching than the coil/capacitor combination. This is often the case with a
folded unipole being used for stereo
operation. In this case, replacing the
shunt capacitor and coil with a vacuum
variable capacitor may result in superior
audio quality.
Next month we'll look at the currents
and component ratings in the various
legs of the ATU network.
65.3511,
-
Figure
Shunt example
values I need. If you would like a copy of
the calculator program, I will make it
available on request. The program
calculates all the legs for a tee network
and also gives the equivalent values in
microhenries and microfarads.
Look again at Figure 1(a). You want to
transform the antenna's 619 base
resistance to match the 7011 transmission
line. There are literally hundreds of leg
value combinations that will provide this
match, but each combination also produces another important characteristic-phase shift. In the case of a nondirectional antenna, it used to be said
that phase shift didn't matter. However,
with the increased interest in fidelity and
antenna characteristics, phase shift, even
in a non-directional system, should be
considered.
The easiest tee network calculations
involve a phase shift of 90°. Figure 1(b)
shows the results of this equation:
1. Typical tee network ATU as shown
in a. In b, same network showing matching
impedances with 90° phase shift. In c, a
matching network is developed by adding
+j25.3511 reactance in series with Z,.,.
Calculations
Although most engineers have been
exposed to the equations for calculating
the reactance of coils and capacitors, it's
still difficult to do. Unfortunately, the
equations are cumbersome and often
lead to mistakes, but there are computer
and calculator programs to calculate
these values. One of the easiest ways to
solve these problems is with a frequency/reactance nomogram, which calculates the equivalent reactance in
microhenries or microfarads. These
nomographs are published in many
handbooks, so look around for one.
I use an HP -65 calculator to derive the
September 1986
www.americanradiohistory.com
-j
Editor's note: For a copy of the calculator program,
write to John Battison, 890 Clubview Boulevard North,
I :T:)))))
Columbus, OH 43085.
makes your
channel sound as
good as it looks
C RL
Stereo audio processing is in
future. That's why there's no time
ice :he Dresent to select the stereo
Ì.idio processing system that will meet
dour needs fo- years to come.
A system like the CRL TVS1 televis oi studio processor and
TVS-30C2 stereo limiterlgenerator. Both
a -e designed with the superior
performance features your station
r
3
is.
Ycu won't find a more
i-telligently designed, high -quality TV
n
stereo processing system any.-here. So,
pia- for the future now with C
T.'S001 and 3002. Designed to make your
chen-iel sounc as good as i: Icoks.
Call or write CRL today for
complete information and a mo-cost
demonstratioi.
.11M
NeafflAiMiii
iiMMEK
BIM WEI
o==
IMF'
ZOMII
111/ATrssA
Vi V
CRL
it
V
Systems
:2f.22 Wem Geneva Drive
Tempe, Arzona 85282
(800) 53E-7648 (602) 438-88
TELEK: 350464 CRL 7NIPE. LD.
Circle
www.americanradiohistory.com
(9) on
eply Card
¡Satellite technology'
Rating
earth -station systems
By Elmer Smalling Ill
0.6dB/°K. This might make a difference
in a fringe reception area or where the
antenna is of marginal size.
Let's consider two important,
but often
misunderstood, equations used in connection with earth -station design and
operation. The first is:
G/T =
G
-lOxlogto(T),
or the figure of merit of an earth station
is equal to the antenna gain less 10 times
the common logarithm of the sum of the
noise temperature components of the
system.
The second equation is:
Determining the noise temperature
figure is a bit more difficult. You must
find the total noise contribution of the
system. The three main contributors are
the antenna noise temperature, the LNA
noise temperature and the passive equipment noise temperature. You can find
the antenna noise temperature from the
antenna specs or from the manufacturer.
For this example, the antenna has a
noise temperature of 22 °K (Kelvin).
C/N = G/T-LD-LM-K
-10 x log, D(B)+ EIRP.
A: MAIN LOBE
8: FIRST SIDE LOBE
or the carrier-to -noise ratio of a system is
equal to the system G/T less the path loss
from the satellite to receiver less
N
miscellaneous system losses less
Boltzmann's constant less the receiver
noise bandwidth plus the effective
isotropic radiated power of the satellite.
The figure of merit was devised to easi-
ferent earth -station receivers. An earth
station might combine a large, high -gain
antenna with a mediocre amplifier.
Other systems might use medium or
small dishes with high -gain amplifier
systems. You cannot tell the performance of the system simply by examining
a single component such as the antenna,
LNA or receiver. Because the combination of available components is quite
varied, the G/T or figure of merit is used
to handicap any system with respect to
its signal -gathering power.
Equation 1, the figure of merit ratio, is
easily calculated. The gain figure is the
gain of the earth -station antenna
measured in dBi (decibels above the
value of an isotropic or imaginary dipole
in free space that emits equally well in all
directions). This figure can be requested
from the antenna manufacturers or
calculated using common reference
sources. For these purposes, use 43dBi
for the gain figure G, which is the approximate gain value of a 4.5m diameter
parabolic antenna at 4GHz.
Smalling, BE's consultant on cable/satellite systems,
is president of Jenel Systems and Design, Dallas.
14
D
,80.
48
G/T
ly compare performance figures of dif-
OTHER SIDE LOBE
RESIDUAL GAIN
C:
D.
OFF -AXIS ANGLE
B
(DEGREESI
Figure 1. Related to the figure of merit of the
performance. Gain
must be controlled according to the formula
G=32-251og,D0 for 1°<048°. Although the
gain restriction applies to transmitting antennas primarily, it also affects receiving performance.
antenna
is the side lobe
is sold according to its noise
it can be found on the
In this case it is 100°K. The passive
The LNA
temperature, so
label.
equipment noise temperature of the feed
system is 3 °K (an average system figure).
Now you can apply all of these factors
to the equation:
G/T =
G
-10 xlogto (Tn)
-lOxlogtf/(22+100+2)
=43 -10xlogto124
= 43
= 43
-10 x2.09
G/T = 22.1
You could make the equation more
detailed by adding precise passive noise
temperatures or system losses, but
because the noise temperature calculations are logarithmic, it would take large
changes to affect the video quality. Keeping everything else fixed and changing
the LNA to a superior 85° unit buys only
Broadcast Engineering September 1986
www.americanradiohistory.com
C/N
Equation 2, the carrier -to-noise ratio,
involves several factors besides G/T. The
second and third elements are simple
losses measured in decibels. The first,
LD , is the path attenuation from a
geostationary satellite at 22,000 miles
above the equator. This loss is approximately 196dB.
The second loss, LM is the total of
many small miscellaneous losses, including atmospheric absorption, rain attenuation, satellite earth -station pointing
error, FM threshold margin, polarization
loss and long-term satellite degradation.
Each of these losses is small (< 1 dB each)
and, for these purposes, may be lumped
together as 2dB.
The third element, Kelvin (or K), is a
physical constant that was discovered by
19th century scientist Ludwig Boltzmann
which relates molecular activity to
temperature. When converted for this
,
Boltzmann's
use,
-228.6dBW/ °K.
constant
is
The next factor is 10 xlog(B), or 10
times the common logarithm of the
receiver bandwidth. For this example,
the bandwidth is 36MHz.
The last figure is the effective isotropic
radiated power of the satellite you wish
to receive. Although isotropic refers to a
lossless, omnidirectional, free -space
dipole, it is used in most literature for
satellite ERP. For this example, assume
an ERP of 34dBW.
The C/N equation now becomes:
C/N = G/T -LD -LM -K
-lOxlogtgB +EIRP,
-196 -2 -(-228.6)
-75.5 +34,
= 22.1
C/N = 11.2dB
To ensure a noise-free system, make
certain that your C/N level is always at
least 3dB over the receiver threshold
level. This level can be found in the
receiver specifications. A simple way to
improve G/T or C/N ratios is to increase
the size of your antenna and/or use a
low -temperature LNA (60°K to 85°K).
:t4)111
))11
WHETHER IT'S NEW CONSTRUCTION
OR RENOVATION ...
Your goal
is to be the best in your market by building a facility that will produce
operating efficiencies and a superior on -air look. Lerro Corporation can help
you bring together all the pieces of the technology puzzle to create the most
cost-effective physical plant you need to sell your services
Lerro uses the interactive team approach, with you providing inputs on your
marketing strategy, both short and long range sales goals and cost constraints
We offer technological solutions using our broad equipment lines, product
knowledge, and advanced engineering tools
A Lerro designed and constructed facility along with our follow-up training,
maintenance program and warranties will create an environment for you to
market your product with quallity, efficiency, comfort, and profitability.
Call the Lerro half of your design team today!
THE
LERRD
CORPORATION
3125
N. Broad
St., Philadelphia,
Pa.
215 - 223-8200
www.americanradiohistory.com
19132
Circuits
Synchronous AM in
FM systems
By
Jerry Whitaker, editor
11rrr1i`r
rltit
T1'i ;r=.
The
amount of synchronous AM in an
FM transmission system is a function of
bandwidth and carrier deviation. As discussed in last month's column, an FM
system can be tuned for optimum performance by observing the amplitude and
frequency of the synchronous AM component. The effect of bandwidth on
overall system performance for synchronous AM is plotted in Figure 1.
Notice that as the -3dB points of the RF
system passband are narrowed below
400kHz, a dramatic increase in synchronous AM occurs.
performance degradation and
According to research on the effects of
bandwidth restriction on FM transmission system performance (see the bibliography), three basic classifications of
degradation can be identified: moderate,
narrow and very narrow bandwidth
systems.
0.4
=
lZy¡
-
estimate).
Because infinite bandwidth is required
for perfect performance from an FM
system, any reduction in bandwidth will
only degrade the demodulated program
signal. All physical systems, however,
limit bandwidth to some extent and so
the requirement for infinite bandwidth is
compromised. The extent to which it is
compromised is more or less under control of the user. A properly designed
1s-
ó
3
21.0 -
0.3
NOTE: 1. F MOD = 15kHz
2. A f = 75kHz
3. SINGLE.TUNED CIRCUIT
-
0.5
0a0.5
1.0
1.5
2.0
2.5
3.0
3.5
SYNCHRONOUS AM (%)
Figure 1. Typical synchronous AM content of
an FM signal as a function of system bandwidth.
The data presented in Figure 1 is applicable to any bandwidth -limited FM
system, including FM broadcast transmitters, TV aural transmitters, STL systems,
diplexers and transmitting antennas.
Bandwidth also affects the distortion
floor of the demodulated audio signal of
an FM system, as plotted in Figure 2. The
data applies to a test setup involving a
single -tuned circuit fed by an FM signal
with a deviation of ±75kHz at a
modulating frequency of 15kHz (no de emphasis is applied to the output signal).
Remember that FM is a non-linear process and that interpretation of distortion
numbers for multiple signals, such as
stereo, is not accurate. The Figure 2 example, however, illustrates how the
bandwidth of the RF channel can set a
minimum performance limit on system
total harmonic distortion (THD).
Effects of bandwidth
Bandwidth restrictions that result in
the generation of synchronous AM and
increased THD also affect other elements
of the broadcast FM or TV aural signal.
For reference purposes, consider an FM
transmission system with a -3dB pass band of greater than 2MHz as a wideband system that presents essentially no
degradation to the air signal. At bandwidths below 2MHz, however, degradation can be observed.
16
Broadcast Engineering
0.1
_
NOTE: 1. o I = 75kHz
2. fm = 15kHz
o--
transmitter can provide wideband
3. NO DEEMPHASIS
4. SINGLE.TUNED CIRCUIT
0.1
0.2
0.3
0.4
0.5
a
noticeable loss of quality in on -air sound.
Furthermore, the system may be
unstable with time and temperature.
Critical parameters include:
stereo-to-SCA crosstalk 40dB or less,
IMD approximately 0.5%,
THD approximately 0.5%,
stereo separation 30dB to 40dB (because of composite rolloff),
synchronous AM approximately 5%
and
increased SCA-to-stereo subchannel
crosstalk (typical figures difficult to
0.6
0.7
0.8
0.9
-3dB BANDWIDTH (MHz)
Figure 2. Typical total harmonic distortion
(THD) content of a demodulated FM signal as
a function of transmission-channel bandwidth.
A moderate bandwidth system is defined as a transmission channel exhibiting a -3dB passband of from 1MHz
to 2MHz. Effects on stereo performance
include increased stereo-to-SCA crosstalk
and reduced stereo separation relative to
performance if properly tuned. Figure 3
shows an actual plot of an FM transmitter
passband using a cavity -type PA circuit.
Note that the -3dB passband is 2.2MHz,
which places the system into the wideband category discussed previously.
Modern transmitters are capable of such
performance. It is up to the engineering
staff to achieve it.
25-
oo
the wideband (greater than 2MHz)
system. From the standpoint of practical 15performance, however, a moderate
2.2MHZ BANDWIDTH
AT -3dB
bandwidth system is essentially trans- 10parent to program audio.
A narrow bandwidth system is defined
as a transmission channel exhibiting a
5-3dB passband of from 0.5MHz to
1MHz. Typical performance limits are:
stereo-to-SCA crosstalk 50dB to 60dB,
108.5
107.5
108
107
intermodulation distortion (IMD) apFREOUENCY IMHz»
proximately 0.2%,
Figure 3. The measured overall bandwidth of
THD approximately 0.2%,
a 25kW FM transmitter.
stereo separation approximately 50dB
and
Bibliography
synchronous AM approximately 1%.
Hershberger, David, and Robert Weirather. "Amplitude
A very narrow bandwidth system is
Bandwidth, Incidental AM, and
Phase
Bandwidth,
Saturation Characteristics of Power Tube Cavity
defined as a transmission channel exAmplifiers for FM," Harris Corporation, Quincy, IL,
hibiting a -3dB passband of less than
1982.
I:t4)111
will
experience
a
system
0.5MHz. Such
10145
September 1986
www.americanradiohistory.com
DENSITY determines the
input drive level to the Six Band Limiter. Lets you
have it your way-open
and transparent, or solid
and dense.
CLIPPING
adjusts the
BASS EQ provides peaking boost at 65Hz, making it easy to get the
solid punch you need for
drive level into the multi -
band clippers, determining the loudness/
distortion tradeoff.
many
contemporary
music formats.
AO 14i
O
BAND
1.11.11T.11
Gain reduction meters for
each band: they provide
the information you need
for accurate setup.
Many FM stations perpetually seek
"the perfect sound". OPTIMOD-FM
alone does it for many. The OPTIMOD
XT Accessory Chassis improved results
for some. Still, some seek even more
BRILLIANCE boosts the
10kHz band. Use it to increase the sense of "air"
and "transparency" in
your music.
PRESENCE boosts the
3.7kHz band to achieve
midrange balances right
for your format.
THE NEW ORBAN
6 -BAND FM LIMITER.
from OPTIMOD-FM.
We listened.
Our NEW 8100A/XT2 Six -Band Limiter
Accessory Chassis (which works with
any 8100A OPTIMOD-FM) features two new high frequency equalizer controls: PRESENCE and
BRILLIANCE. They complement the original
8100A/XT's bass EQ controls, and give you twice
the flexibility of the single HF EQ control typical
of other add-on multiband processors.
With an XT2, your OPTIMOD-FM system is
totally immune to operator gain-riding errors
because the dual -band compressor in the main unit
is converted into a smooth, slow AGC to ride gain
ahead of the XT2. Any reasonable input level
operates the XT2 in its "sweet spot," so there's
never any need to add external, potentially
incompatible compression.
This is good news because the time -constants
and other processing parameters in a pure,
integrated Orban system have been carefully
harmonized to achieve an overall sound that's
loud and bright, yet remarkably open and free
from audible side-effects.
(WE LISTENED)
The XT2 also excels in the most difficult of
processing tradeoffs-delivering loudness on music
while keeping speech free from clipping distortion.
Credit this uniquely capable performance to
Orban's patented multiband distortion -cancelled
clipping system-which we were able to implement in the XT2 system because the XT's circuitry
is fully integrated into the processing system, not
just tacked onto the front.
The XT2 lets you have it all: natural sound,
source -to -source consistency, loudness, clean
voice, and adjustability that lets you tailor bass and
treble to your taste and format requirements. And
thanks to its efficient single -chassis construction
and its use of the main 8100A power supply, it lets
you have the next step in Optimod processing at
an exceptionally reasonable price: $2075 (suggested list).
We listen to our customers. Listen to our new
XT2. We think you'll like what you hear.
Orban Associates Inc.
645 Bryant Street, San Francisco, CA 94107
(800) 227-4498 or (415) 957-1067 Telex 17-1480
«bon
Circle (10) on Reply Card
www.americanradiohistory.com
r
1
Troubleshooting
Repairing
digital systems
By Martin Plude
Maybe
you've run into the following
situation: You're servicing a digital circuit, and have located the section of the
board where the problem exists. You've
identified a suspect IC. It's a 20 -pin TTL
(or CMOS) device that has been conveniently wave -soldered solidly into place.
The only way you can think of to test
your hypothesis is to swap ICs, so out
comes the soldering iron. You spend a
considerable amount of time removing
and gingerly replacing the device. You
take a deep breath and apply power to
the unit. The problem is still there.
There's a better way to track down
problems, without unsoldering anything.
Instead of pulling out the IC (and your
hair), you can use a device called a logic
comparator to test the IC in -circuit.
Logic comparators
Logic comparators are available from a
number of manufacturers. They are
similar in operation and offer a quick
way to identify a bad (or good) IC. As the
name suggests, logic comparators use a
comparative principle to check a known good reference IC against a questionable
IC in the circuit under test. This method
involves placing the known -good IC in
the comparator, clipping a connector
over the in -circuit IC and observing a
go/no-go indicator.
Before using a logic comparator, first
determine the type of IC technology being used in the circuit-either TTL or
Because of the difference in
CMOS.
voltage requirements for TTL (+ 5V) and
CMOS (+5V to + 18V) ICs, instrument
manufacturers offer different models to
meet the operational requirements of
each technology.
When the IC has been identified, check
an IC data chart (usually supplied with
the logic comparator) to determine the
Vcc and ground configuration of the
device used in the circuit. Most ICs use
the standard Vcc and ground arrangement shown in Figure 1, but there are
just enough special configuration devices
in use that the IC chart should always be
consulted. DIP switches allow nonstandard configuration of Vcc and
ground to be selected.
Typical setup of a logic comparator involves locating a source of Vcc and
ground on the circuit board for connection to the logic comparator. Logic comparators draw their own small power requirements from the circuit under test,
mainly to light up the LED pin indicators.
After hooking up the logic comparator
to power on the board, attach the test
clip to the suspect IC. Remove the
known -good reference IC from its antistatic case and place it in the logic comparator. Push the test button to initiate
the comparison.
If the IC under test is good, the tester
will indicate it. If the logic states do not
agree, a fault indication will be
displayed. LEDs adjacent to the knowngood IC will light at those pins where the
logic state of the device under test is different from the reference IC. This information may direct you to another IC or
suggest another test, such as logic state
activity.
Vcc
Vcc
GND
GND
14 -PIN
16 -PIN
Vcc
20 -PIN
Figure
for
GND
power and ground pinouts
and 24 -lead ICs.
1. Typical
14-, 16-
Versatility
planning and communications, B&K-PrecisionlDynascan, Chicago.
Plude
18
is manager, marketing
Broadcast Engineering
The logic comparators that are
available on the market can handle stan-
September 1986
www.americanradiohistory.com
dard and non-standard Vcc and ground
pin configurations. For non-standard
power configurations, the appropriate
connection is engaged via a toggle or dip
switch on the comparator.
Because of the small size of logic comparators, they can be used both on the
bench or in the field for on-site replacement of ICs. Logic comparators can save
servicing time, because the questionable
component is analyzed with the equipment in its dynamic, normal operating
condition.
Some logic comparators also include a
logic monitor feature, which displays the
full logic state of devices with up to 20
pins at one time. This is significantly
faster then individually probing each pin
with a logic probe. In addition, this type
instrument provides information
unavailable from a logic probe-simultaneous comparison of logic states at two
or more pins.
of
Applications
Although logic comparators are major
time savers, they are not 100% effective
in every application. For example,
counters and shift registers must be reset
to synchronize the reference IC with the
IC under test. Otherwise, erroneous test
results may occur. Also, with some
models, high-speed triggered devices
cannot be compared. The small propagation time delay of the cable and tester
prevents identical timing in both ICs.
Other devices may require special consideration for proper testing.
Logic comparators are not intended to
replace standard test instruments in the
troubleshooter's bag of tricks. Oscilloscopes, digital multimeters and logic
pulser probes have their special benefits.
In certain circumstances, however, a
logic comparator provides a versatile,
hand-held device to verify the operation
of questionable ICs in -circuit and under
power.
Editor's note: With this issue, we begin a series of articles discussing how users can troubleshoot and
repair digital -based hardware. The growing use of
digital equipment in broadcast stations has
dramatically increased the need for engineers to be
proficient in the repair of advanced electronic
systems.
I:
-))))j
Dealers'
ch _'cep
JVC's CR-85CU Editing VCR. It's
the one video dec lers choose
when selecti'gVCRs for 3/4"editing.
On-line systems. A -B roll systems. Off-line systems. Remote
vans. Rental departments. Newsroom editing. Computer graphics.
Animation systems ... Just a few of
the applications where customers
need the best and dealers choose
the CR -850U to make sure they
get it.
Why the C R -850U? Excellent
picture quality: the result of an
increased S/N rat o, Y-688 dubbing,
special noise reduction circuitry.
Fast, accurateed Ling: the benefit
reaped from -1- e c rect drive tape
transport system and the separate
SMPTE time code address track.
The new front bad, rack -mount
design with paral Cl and serial
remote contrD capability allow
easy interface win existing and
new edit systems Built-in self
Circle (11) or Reply Card
www.americanradiohistory.com
Z.)
diagnostic circuits with front panel
test points speed maintenance
and adjustments.
Dealers' choice, yes' But the
odds are always in your favor,
whatever your application, with
the JVC CR -850U.
See your JVC Professional
Video Cealer today or, for literature
call toll -free:
1-800-J VC -5825
JVC COMPANY OF AMERICA
Professional Video
Communications Division
41 Slater Drive
Elmwood Park, NJ 07407
JVC CANADA,
ScarborDugh, Ontario
¡Management
foNeiigrneers
Develop a style
to call your own
By Alfred
P.
Hahn
My first day as a shift supervisor was a
flop. It's been 18 years since then, but
I
still remember it well.
I was 21 years old, not long out of the
Army. My boss liked my aggressiveness
and put me in charge of a shift, supervising another technician who was far
superior to me in experience. The first
night, I was King Kong. I tried to order
the technician around, and he didn't
want any part of it. The next day I
stormed into my boss's office insisting
that I wanted to fire the technician. His
response was, "You can't go around firing people." He moved the man to a different shift.
Looking back, I realize that I acted
really foolish. I was overcontrolling. I
thought that management meant bossing
people, which it doesn't.
My second management job taught me
how management can get burned. Determined not to repeat the King Kong
mistake, I developed a positive relationship with the engineers and technicians.
I was well respected and "one of the
boys." Then, one day, the payroll clerk
asked me why I had approved overtime
for a technician who called in sick.
As it turned out, the technician had
been putting in false overtime claims for
some time, even before I became his
manager. Being the nice guy, I hadn't
been paying close attention to the time
sheets-just signing them. We were all
good buddies, so I thought there would
be no problems. Because I was too worried about my relationships with
workers, I didn't appreciate that one of
my duties was protecting the company
by making sure the employees' time
sheets were accurate.
Both of these lessons are part of the
background I have drawn upon for
guidance in dealing with people. The experiences also have been useful in
developing my own personal management style.
Developing your own style
trial and error the only way to
develop a management style that's appropriate for the broadcast business? The
Is
short answer is yes, but. To speed the
process, training in management skills
and philosophies helps significantly by
heading off many painful mistakes and
buying time to grow out of problems.
Hahn is president and founder
Technologies, Portland, OR.
20
Broadcast Engineering
of Support
The long answer requires some selfanalysis. That means defining a management style and how if differs from a
novice manager's raw instincts.
It's helpful to consider that supervisors
and managers must perform in several
dimensions. A technician's position, on
the other hand, requires competence in
only two dimensions: dealing with faulty
equipment and interacting with bosses.
Moreover, non -managers (technicians)
receive positive strokes almost daily.
They are heroes in single combat of me
vs. machine. They walk in on chaos and
return it to order. If they're really good,
they also make the non -technical people
feel good about their equipment and the
engineering department's service.
The positive strokes for supervisors
and managers aren't as generous, nor as
frequent. Positive reinforcement, as well
as the ability to see the tangible results of
a day's work, are two surprisingly important job satisfaction elements. Often,
managers rely on other activities, such as
hobbies, to compensate for this lack of
job satisfaction.
Some novice supervisors perceive
their roles as coach or leader and, to
some degree, they are. However, becoming the leader of the TGIF club at the expense of other job dimensions is inviting
failure. Such managers will be perceived
as unable to effectively evaluate or
truthfully critique employees.
Management isn't a popularity contest,
and it is important for the manager to be
results -oriented. Any chief engineer or
director of engineering who doesn't
understand the bottom line is in for a real
surprise. Station managers expect their
chiefs to understand the value of an efficient engineering department. A chief
engineer who fails to direct the engineering staff in an efficient manner, both in
terms of personnel and equipment, may
be looking for other employment.
Multidimensional behavior
One key to effective management is
multidimensional behavior. The term
simply means that you adapt your
responses to problems based on each
particular situation. A good supervisor or
September 1986
www.americanradiohistory.com
manager doesn't respond to every crisis
in the same way.
Unfortunately, multidimensional behavior is uncomfortable or even impossible for some engineers. This is
especially true for engineers who have
spent a great amount of time dealing only with equipment and have developed
few interpersonal skills. Engineers who
have broader backgrounds usually find
themselves somewhere in the middle-learning day by day.
Some people perform well in some
managerial dimensions, but not in
others. They ultimately fail because they
can't achieve a balance. For instance,
someone may be excellent in dealing
with supervisors and subordinates but
cannot relate well to peers in other station departments.
A manager needs peer -level respect to
effectively communicate with other
departments within the station. Without
effective interdepartmental communication, the engineering manager is in a
continual battle for support in terms of
resources and respect.
Engineering managers who are task oriented often feel inadequate in giveand-take encounters with peers. These
managers want to deal on a black -andwhite basis-things must be done their
way or else. They will even use a little
brinkmanship to get their way. When
they become uncomfortable with peers,
they either try an autocratic bluff or
retreat to their offices to hide out for a
while. It is the classic fight or flight reaction to stress.
On the other hand, no one likes
managers who spend all of their time appeasing their bosses or who sacrifice
subordinates to make themselves look
good. Clearly, a balance is needed.
Managers who are not multidimensional
can be blindsided. It is necessary to
develop techniques for dealing with
problems and reaching goals that earn
the respect of your subordinates, bosses
and peers. A good management style
does that for you.
If you are currently in an engineering
management position, you may have
identified some of your strengths and
weaknesses. If you are not a manager, do
you hope to become one? In either case,
additional training may be helpful.
Editor's note: This article was adapted from "Personalizing Your Management Style," which appeared
in the July 1986 issue of Microservice Management
magazine, an Intertec publication.
' -r:))))1
-Dazzle 'm with technical brilliance. Everybody's talking about CD's
and digital. It's as if all analog tape
technology and the cart machine
were obsolete. Although CD's are a
terrific new program source, it
should come as no surprise that
carts are still the best way to handle the huge quantity of individual
program elements that comprise a
typical day in radio broadcasting.
What else can play spots,
promos, sound effects, news actualities, ID's and music so easily?
Carts have been around for
thirty years because they're a great
package-easy to handle and store,
easy to record and re-record, easy to
label and identify. Best of all,
they're cued-up from the moment
you put them in the machine.
Try that with a CD, turntable or
reel tape!
The engineer's challenge is not
CD versus the cart, vinyl LP or reel
tape-but improving all broadcast
source and delivery systems. Digital
audio technology is here with exciting potential for the future. For
today's programming needs though,
you can't beat the features and performance of our Tomcat and
Micromax cart machines.
Tomcat and Micromax are
equipped with our Maxtraxewidetrack tape heads which give you
nearly twice the stereo track width.
This track format, coupled with our
superior recording and reproduction
circuitry, maintains the fidelity of
Cart 'em-up
with
TomcatTM &
Micromax:
1985. Pacific Recorders & Engineering Corporation
www.americanradiohistory.com
master quality sound sources better
than any other cart machine.
A lot of #1 stations depend on
Tomcats. For stations on a tighter
budget, our Micromax is the best
choke. Both are built rugged to
last-designed with the best
components money can buy. Both
will make your station sound great
with everything you cart-up, especially CD's.
Give us a call now for all the
technical details on the "Digital Age"
cart machines.
The Choice for More
#1 Stations.
Pacific Recorders & Engineering Corporation
2070 Las Palmas Drive
Carlsbad, CA 92008
(619 438-3911 Telex: 181777
Circle (12) on Reply Card
Wired for stereo
By David L. Bytheway
Develop a fresh approach to audio interconnection-without forgetting
the traditional methods-and your stereo TV audience will hear the difference.
stated that all outputs should be 5011 or
less and that all inputs should be 10k11 or
higher. With the exception of some
broadcast equipment, the majority of
professional audio devices manufactured
today conform to this standard. The use
of voltage matching is the key to improving audio performance.
The first and most important advantage of voltage matching is the large increase in bandwidth that is possible on a
system level. Second, interconnections
and terminations are easier. Every output is treated as a voltage or low impedance source, every input is treated
as a bridging or high -impedance load,
and no terminating resistors are used.
Equipment patching is straightforward
and simple. With this scheme, you can
feed multiple loads from one source.
Third, because smaller signal currents
flow, less crosstalk is produced.
Capacitive coupling is also reduced as a
result of the lower impedance held on
VOfV10EMKTCh ED
at
SAMS
To many of you, the word audio
con-
jures up thoughts of demons, nightmares
and black magic. The basics of audio are
simple to understand, but in practice,
there are many problems to solve on the
way to obtaining topnotch performance
in a broadcast installation, especially
with the new demands of TV stereo.
You don't really have to learn black
magic, however, or fumble your way
through nightmarish ordeals with the
demon audio. Although there are many
possible ways to get the most out of your
equipment, the simplest methods are the
best. The following is a collection of
ideas that will help you take a fresh, upto-date approach to achieving optimum
performance from your TV audio
facilities.
Voltage matching
The traditional method of interconBytheway is an analog circuit design engineer for the
Robert Bosch Corporation, Salt Lake City.
22
Broadcast Engineering September
necting audio equipment in the broadcasting world is based on 60011 sources
and loads in all audio equipment. This
standard comes from the early telephone
days, when open wire transmission lines
had a characteristic impedance of 60011.
Because the equipment used with these
lines had 60011 input and output impedances, 60051 became the standard for
audio interconnection, and is still in
general use today.
Advances in monolithic technology
have made it possible to design both input and output stages with far better
performance than older designs, which
relied on signal-coupling transformers.
Besides providing lower distortion, lower
noise and better handling of balanced
lines, op-amp -based circuits make it
possible to use the technique of voltage
matching to its fullest advantage.
The basic idea of voltage matching is
to use low -impedance sources and high impedance loads everywhere. In 1978,
the International Electrotechnical Commission (IEC) published a standard that
1986
www.americanradiohistory.com
100
1K
10K
100K
Figure 1. Frequency response of a 1,000-foot
cable when used in both voltage -matched and
6000 impedance-matched systems. The
markers represent the -3dB points.
100
1K
10K
100K
Figure 2. Frequency response of a 1,000-foot
cable with various values of source impedance. The flattest response results in a
source impedance of approximately 600.
1
C
RL
c
L__
Figure 3. Circuit model used to approximate the characteristics of an audio cable less than one-
tenth wavelength long at 20kHz. The frequency response depends on the line's load and source
impedances.
the line. Fourth, the reduction in loading
provides a more linear operation. Almost
all output circuits in general use today
have higher distortion when operated into their minimum rated load impedance.
Filth, voltage matching provides greater
headroom and dynamic range.
Comparisons
In order to see the relative advantages
of using voltage matching, some tests
were made on a typical audio cable (a
twisted pair with foil shield) 1,000 feet
long. These tests were conducted with
wideband transformerless balanced
dryers and receivers. The source and
load impedances used on the 1,000 -foot
cable were varied according to the test
conditions.
The lower plot in Figure 1 shows the
cable's frequency response with the
typical 60011 source and load impedances. The upper plot shows the
same cable using an optimized voltage matching technique. There is an increase
of almost eight times the bandwidth.
Note also, that with voltage matching
there is essentially no level loss in the
passband from terminating the cable.
The 60011 termination produces more
than a 6dB loss in level.
Optimum output impedance
Some engineers believe that the best
way to accomplish voltage matching is to
use an output impedance that is as low as
possible. They think this will overcome
the audio cable's capacitance and provide the most bandwidth. Recent
research shows, however, that the 011
output impedance is not optimum. In
fact, it can cause frequency response
peaking and transient overshoot.
Figure 2 shows the frequency response
of a typical 1,000 -foot audio cable terminated with a high-impedance load and
driven with various source impedances
ranging from 011 to 60011. The driving
impedance that provides the widest
bandwidth and flattest response is about
peaking is produced, an empirical circuit
model was developed to analyze these
audio cables. Figure 3 shows that the circuit formed is essentially a second-order
low-pass filter. The filter's frequency
response is dependent upon all the circuit values. When the R, L and C of the
cable are fixed according to the cable's
length, then the response is determined
by the source and load impedances connected to the cable.
This lumped circuit model corresponds
to the incremental model used to derive
transmission line characteristic impedances. At audio frequencies, the wavelength of the signals is much longer than
the length of the audio cables. Therefore,
the cables do not exhibit transmission
line effects.
The free -space wavelength of a
20,000Hz signal, for example, is 15km,
which is approximately 9.3 miles. It is
generally considered that when a cable is
one-tenth of a wavelength or less, the
cable does not exhibit any transmission
line characteristics such as reflections or
standing waves. This makes it possible to
use audio lines of 5,000 feet or more
without having to consider transmission
line effects. One audio system built in
1983 successfully handled cables of
3,000 and 7,500 feet in length with
superior results because the cables were
driven with voltage -matching techniques
and used no transformers.
Alternatives to voltage matching
Some broadcast plants have used 15011
impedance matching to lower the effects
of cable capacitance and to increase
bandwidth. Although this does result in
some increase in bandwidth, the benefits
are still not as great as those of the
voltage -matching method. Figure 4 illustrates the difference between a voltagematched system and a 15011 system driv-
1.000 FEET
.l
l
L.
ing the same 1,000 -foot cable. The 15011
load requires much higher driving currents from the output stages, resulting in
higher distortion levels. The increased
distortion levels result from the difficulty
in designing high-current, low-distortion
output drivers. Figure 4 also shows increased voltage drop from the cable
resistance, which forms a voltage divider
with the load. In addition, equipment
selection for this type of system is limited
because most audio devices are designed
for 60011 loads.
System simulation
To simulate the frequency response of
an actual audio system, additional tests
were conducted using three distribution
amplifiers, a routing switcher and 2,000
"OEM
TCI. ED
1-
1500
100
1K
100K
10K
Figure 4. Comparison of frequency response
for a 1,000-foot cable when used in voltagematched and 15051 matched systems. Markers
represent the -3dB points.
feet of audio cable (see the block
diagram in Figure 5). These are standard
off-the -shelf products, designed for
voltage matching with a -3dB point of
approximately 160kHz and a frequency
response specification of +0, -0.1dB
from 20Hz to 20,000Hz.
The total system response is shown in
Figure 6. The upper plot is the frequency
response of a voltage-matched system
with 6611 sources and 20k11 loads. The
lower plot is the same system with 60011
impedances throughout. The results are
dramatic. The 60011 system is approximately -9dB down at 20kHz, while the
voltage-matched system is less than
-0.3dB down at the same frequency.
These results speak for themselves.
Note that the system's frequency
response limiting factor is not the
Continued on page 26
1.000 FEET
ROUTING
SWITCHER
602 Therefore, when a voltage matched system is used, the best output
impedance for driving typical audio
.
cables is from 5011 to 6011. These results
have been confirmed by a number of independent sources over the past few
years and entire facilities have been built
this way.
Circuit model
To show how this frequency response
NETWORK
ANALYZER
O IN
Figure 5. Block diagram for a
test setup
of 2,000 feet of cable, three DAs and an audio routing
switcher.
September 1986
www.americanradiohistory.com
Broadcast Engineering
23
www.americanradiohistory.com
"Makegood?
What's a
makegood?"
How soon they forget.
All those people from Anchorage to New York who already
use Sony BetacartsM Systems.
They forget about downtime. They forget about on -air
backup systems. And they forget about ad agencies demanding
.,./..AA,`~1-t
damngood makegoods.
Why?
Betacart is the smart cart machine.
91k4
e@ri
Microprocessors keep constant track of
:
e
alignment.
system
maintain
They
forty cassettes.
< it J é ,.
P }'%
They
y run self-check diagnostic routines.
% j
And Betacart's simple operation not only
prevents human error, it prevents human boredom.
Technicians at KDNL, St. Louis use their
Betacart to put snap into station breaks. For station IDs '
they shoot logo artwork, add movement with digital effects and
air the cassettes through the Betacart. Now there are no more
dull title cards at KDNL.
At WDBJ, Roanoke, commercial delivery has improved
dramatically. So has the picture quality of the spots.
Carl Guffey, director of operations, reports: "The sales
staff is happy, traffic is happy, the engineers are happy and the
ogeneral manager is ecstatic:
Want to improve your station's commercial outlook?
Put the Gold Standard to work for you.
Call Sony Broadcast at (201) 833-5231. '1 :
` le
f-.
7
i
'.
SONY
1
Sony Broadcast Products Company, 1600 Queen Anne Rd., Teaneck, NJ 07666. © 1985 Sony Corporation of Americo. Sony
and Betacart o trademark of Sony Corporation. Photographed at WNET, New York.
r
Is
a registered trademark
September 1986
www.americanradiohistory.com
Broadcast Engineering
25
Continued from page 23
OL MOE MATCHE
amplifiers, but rather, the cables
themselves. The test was repeated
without the routing switcher. The results
were indistinguishable from the first
test, showing that a system's ultimate
bandwidth may be limited by the cables,
rather than the equipment chosen. This
is true even when using the voltage matching method.
009
10.7k
Ix
voltage -matching operation.
Many
routing switchers, distribution amplifiers,
audiotape machines and mixing consoles
also are manufactured in accordance
with this standard. There is some equipment, however, that will require
modification in order to work this way.
Devices that have a true 60012 input impedance can be modified with simple differential buffer amplifiers that are
available from a wide variety of sources.
Implementing voltage matching
100
1K
10K
100K
Figure 6. Frequency
response of the test
system described in Figure 5 when used in
both the voltage -matched and 6002 matched
configurations.
The vast majority of audio equipment
manufactured today can operate in the
voltage -matching mode. Many of the
more popular videotape machines have
back-panel switches that select 60012 or
COST
EFFECTIVE
System One is COST EFFECTIVE.
,;,24,0)
System One plus PC
(if you don't already own one)
sells for $7,000 to $10,000-less than slower, lower performance IEEE -488 automated audio test systems.
Even more important, you'll have automated procedures running with minutes -to -hours of non -programmer setup time, compared to weeks- to-months
of software effort required by conventional program-
mable instruments.
Audio
precision
2209
Beaverton, Oregon 97075
503/297-4837, 1-800/231-7350
TELEX: 283957 AUDIO UR
Transformers and voltage matching
Transformer-coupled equipment requires careful consideration. Although it
is certainly possible to manufacture
equipment with transformers that meets
the voltage-matching standard, most
broadcast transformer -coupled equipment does not. Most transformer-coupled
equipment actually has an output impedance of 10012 or less. In this case, no
modification is required to lower the impedance. However, the transformer may
need to be loaded properly in order to
obtain correct frequency, level and transient response.
If a device is designed to be terminated
in a 60011 load, simply connect a 60012
load resistor across the output. The
device can then be treated as a voltage
source and connected to the system as
any other equipment. It is best to make
the modification within the equipment
cabinet. This prevents the resistor from
being altered or removed during normal
servicing. After the modification, it may
be necessary to recalibrate or reset the
equipment reference levels. This is
especially true in the case of tape
recorders. Fortunately, much of today's
equipment is actually designed to be
operated into a high -impedance load.
Long lines
PO. Box
INUMAIl1.1aw11Fx1ö1A1W11nMN.1
mKA:l:f
ú
Now, that's the way
to test audio
!
IIIIIIII
When long lines are used, the cable capacitance can present a considerable
load to the line amplifier. For example, a
1,000 -foot cable with a capacitance of
30pF per foot presents a load of 0.03µF.
This capacitance has a reactance of
265.312 at 20,000Hz. An output driver
that is capable of driving a 60012 load
may current limit when attempting to
drive this reactance at high frequencies.
If it does, it may produce a nasty sounding distortion that is similar to slew -rate
limiting. The solution is to use high current output drivers to drive cables in
excess of approximately 500 feet.
Sometimes, low-capacitance cables can
be used where it is necessary to run long
distances.
Terminating the other end of the line
with a low-impedance termination only
makes this problem worse. Because this
termination is effectively in parallel with
the cable capacitance, the termination
further increases the loading on the driving source. High -current output stages
are available in some routing switchers
and
Circle (13) on Reply Card
26
Broadcast Engineering
September 1986
www.americanradiohistory.com
distribution
amplifiers.
These
designs should be used whenever you're
ÌVEWFROIW
ANNAKI5
YTEìJf5
5000 SERIES
The First No -Compromise
Modular Radio Console...
...At A Down -To -Earth Price:
THE FEATURES YOU WANT
-
16 Modular Stereo Channels.
Program, Audition and
Mono Mixdown Balanced Outputs.
Telephone Mix -Minus Buss.
Full Monitoring Facilities.
Remote Equipment Start/Stop.
Remote Module Control.
Standard Digital Clock and Timer.
Optional EQ and Effects Modules.
16
Channels, Under 510,000.
THE DEPENDABILITY YOU
NEED-
DC Controlled - No Audio On Pots.
Rugged Modular Construction.
Penny & Giles Slide Fader.
ITT Schadow Switches.
NE5532 IC Module Desig-1.
External Regulated Power Supply.
Superb Audio Performance Specs.
Most Important, Arrakis Systems
Designed -in Ultra Reliabilty!
For features, performance, price and reliability,
/VOBOOYBL IL05 CONSOLES LIKE ARRAK/5_
Call (303) 224-2248
Circle (14) on Reply Card
ARRAKIS SYSTEMS INC.
2609 RIVERBEND COURT FORT COLLINS, CO 80525
www.americanradiohistory.com
Ia!
arrakis
RELATIVE PHASE SHIFT
10°
20°
30°
40°
60°
70°
80°
90°
Table
1. Predicted
ATTENUATION
0.0662dB
0.2659dB
0.6022dB
-
-
-1.0806dB
- 1.7090dB
- 2.4988dB
- 3.4654dB
- 6.0206dB
attenuation from phase shift between two signals.
forced to feed a long line. Even
transformer -coupled outputs are not immune to this effect. Outputs capable of
driving loads as low as 15012 may be
necessary. This is true even though the
other end of the line has a highimpedance load.
Phase response
What kind of phase response is required to ensure good stereo signal
distribution and mono compatibility?
The audio signal paths should be the
same for both the right and left channels.
The signal's ultimate mono compatibility
is determined by the relative phase
response match for the two channels
rather than the absolute phase response
of either channel alone. Table 1 shows
the level loss when identical left and
right channel signals are mixed and one
channel has a phase shift relative to the
other. Note that even with a 40° phase
shift, the cancellation is just 1dB. If care
is taken to see that the left- and right channel signal paths are the same, there
will be far less than 40° of relative phase
shift between them.
response is one that has a constant group
delay and is smooth and linear as frequency increases. Although this performance is impossible to achieve in practice,
you can come close. The best rolloff
shape to produce these results is the
bessel or maximally flat -phase response
curve. A system will approximate this
desired rolloff when it is free from transient overshoot. An easy way to determine a system's response is to apply a
square wave. When viewed on an
oscilloscope, the output square wave
should have smooth rise and fall edges
with a logarithmic shape. Also, there
should be no evidence of slew -rate
limiting or overshoot.
This criterion was used when choosing
the best output impedance for driving
audio cables in the voltage -matching
tests. Voltage matching, done properly,
not only extends frequency response,
but also produces a more linear phase
response as well. In addition, like frequency response, the ultimate phase
response may be determined by the interconnect cabling rather than the individual amplifiers.
Stereo or mono DA
Distortion and noise performance
Many TV engineers are concerned that
they must have a stereo distribution
amplifier or switcher in order to properly
handle stereo signals. Although it may be
more convenient mechanically, there is
no need to purchase new DAs when
upgrading to stereo, as long as identical
DAs are used for each left- and right channel pair. This is essentially true of all
audio equipment with the exception of
compressors or limiters. These devices
must be operated as a stereo -coupled
pair so that L and R channel gain and
phase relationships remain constant.
A quick comparison of professional
audio equipment and high-grade consumer equipment shows that the professional units often have much higher
distortion levels. It is now possible to
design signal -distribution equipment
with THD levels that are at or below the
device's noise level. Table 2 compares
percentages of THD to equivalent noise
level. When you purchase equipment,
compare its performance to this chart.
Top-quality equipment will have noise
levels close to the THD equivalent noise
levels shown on the chart.
When a complete facility is designed
with this kind of equipment, a signal
from any source could be passed through
Optimizing phase response
In most instances, the optimum phase
THD
1.000%
0.3162%
0.1%
0.03162%
0.01%
0.003162%
0.001%
EQUIVALENT NOISE LEVEL
40dB
50dB
60dB
70dB
80dB
- 90dB
100dB
-
-
Table 2. Comparison of noise and THD percentage leuels. Equipment should haue THD
percentage levels close to the noise level.
28
Broadcast Engineering September 1986
www.americanradiohistory.com
the entire distribution system with no
audible degradation in noise or distortion. This makes it possible to build a
signal -distribution system that can pass
the signal from the best digital source
without degradation. A compact disc
player, for example, is capable of distortion levels lower than 0.002% and a
dynamic range of 96dB.
The simulated distribution system used
in the voltage -matching tests had a
measured noise level of -93.5dBv
(referenced to 0.775V) in a 20kHz bandwidth and a measured THD of 0.0018%
at 1,000Hz through the entire system. In
addition, the maximum signal level was
+27dBv, which gives the system a
dynamic range close to 120dB. This
system could, therefore, pass a compact
disc signal essentially without degradation, because its noise level is more than
25dB better than the disc player and it
has lower distortion levels. This performance level is available from a number of
manufacturers today, but careful equipment selection is needed.
How much headroom?
Experience in the recording industry
has shown that a minimum headroom of
20dB above zero -reference level is needed throughout the entire signal chain.
This is because the human voice can
have a peak-to-average ratio of 20dB.
Newer digital music signal sources require even more headroom, as much as
25dB or more. As a result, the broadcast
plant zero-reference level must be
carefully chosen to provide adequate
headroom.
A +4dBv reference level usually is preferred. Because most of today's equipment has a maximum output level of
+24dBv, this leaves a minimum of 20dB
headroom. This means a + 8dBv system
will have only 16dB of headroom and
may be driven into clipping on many occasions. In order to obtain the 20dB
margin for a +8dBv system, the equipment must be able to handle +28dBv
signal levels.
Although some equipment is available
that can handle these high levels, it is not
common. With the heavy demands of
music, the +4dBv reference, along with
equipment that can handle levels of
+28dBv or more is the preferred option.
This combination gives approximately
24dB of headroom. The lower noise
levels present in today's equipment
make the +4dBv reference level practical, giving a wide dynamic range with
low noise. Most equipment manufactured today can run at either +4dBv or
+8dBv reference levels, so it is not difficult to convert to the +4dB standard.
Balanced and unbalanced connection
Connecting balanced equipment to the
broadcast chain usually is straightforward. However, interfacing to unbalanced equipment can be troublesome,
especially when transformerless equip -
YOU KNOW DATATEK'S REPUTATION FOR QUALITY.
NOW COMPARE US FOR VALUE.
'
al 14
MIN
awe
ai
ü \I
USE THE PERFECT MATES
FOR YOUR STEREO SWITCHING
AND DISTRIBUTION NEEDS.
The D-525
In
®
II
is a 2 -channel
Audio D.A. with
I
The D-4317A
is a
20x2 Monaural or 20x1 Stereo
6 balanced outputs per channel. It can be used
Audio Switcher, self contained in a
for one monaural input with 12 outputs, two
monaural inputs with six outputs each, or one
stereo input with 6 stereo outputs.
Ten D-525 amplifiers fit in one DF -609
5'/4" Rack Frame, providing 120 balanced
monaural or 60 balanced stereo outputs in
only 3 rack units.
Frame. It can be used with a D -4304A
20x1 Video Switcher, for 20x1 videolstereo
Front panel gain controls and clip level
indicators.
Individual power supply.
13/4" Rack
audio switching.
Maximum audio output is + 30dBm balanced
for excellent "headroom" and audio dynamic
range is in excess of 100dB.
Remote control panels operate over a single
coax line.
See Us at SMPTE
Booth #1136
DATATE K
We will be happy to assist in the selection
of Datatek products to meet your exact needs.
Call toll free: 1-800-882-9100.
CORD
1121 BRISTOL ROAD
(201)
Circle (15) on Reply Card
www.americanradiohistory.com
MOUNTAINSIDE, N.J. 07092
654-8100 TELEX 833 541
LEFT
INPUTS
RIGHT
INPUTS
LEFT
SWITCHER
40x40
SINGLE
80x80
SWITCHER
LEFT
INPUTS
40
1
40
40
2
RIGHT
LEFT
OUTPUTS
OUTPUTS
RIGHT
INPUTS
TWO 40x40 MONO SWITCHERS ARE COMBINED INTO
ONE SINGLE -LEVEL SWITCHER, SHOWN AT RIGHT.
40
Figure 7.
A single -level stereo switcher derived from two
801
mono switchers. The design provides
enhanced stereo switching capabilities.
LEFT OR RIGHT OUTPUTS
ment is used. The advantages of trans-
formerless equipment are many and
varied. The greatest advantage is that
well-designed transformerless systems
simply sound better. Entirely transformerless facilities have been built with
great success, and the trend seems clear.
The major objection about transformerless systems is that there is no way to
break ground loops. In fact, a
With Our
Edit Suite
Audio Mixers
transformer is not connected into the
grounds at all. A ground loop can exist in
either type of system. Careful grounding
techniques are important to ensure the
success of transformerless systems. Their
performance often exceeds that of
similar transformer-coupled systems in
terms of noise, distortion, hum rejection,
bandwidth and, most importantly, sound
quality.
Specially designed for television, the
ESAM from Graham -Patten Systems
lets you edit audio the same way you
do video...operating from the edit
keyboard. Only the ESAM has a proven
track record in edit system integration:
for Ampex ACE, CMX, Calaway,
f,19
nonnnn aa
nnnn®nn
nnnnanaau.
Gil
Zit
r
®
..
Convergence, Grass Valley Group, and
other editing systems that operate a
production switcher. Tailored to the
needs of every facility, ESAMs are offered in 8-, 12-, and 16 -input models.
Additionally, an electronically controlled programmable equalizer is available for
the 12- and 16 -input models. Here are just a few other innovative ESAM features:
Operates like
a
video switcher with preset, program & preview busses
Manual & full edit system control of source selection, transitions, & previews
Separate electronics & control panels for maximum flexibility & compact size
Delivers high quality demanded by recording & post production professionals
Yet there's more! For a complete brochure, call us
toll free:
GRAHAM-PATTEN SYSTEMS, INC.
P.O.
See Us At
SMPTE Show,
Booth #746
Box 1960, Grass Valley, CA 95945
Inside Calif.: (800) 422-6662
Outside Calit.: (800) 547-2489
TWX 910-333-6065
Circle (54) on Reply Card
30
Broadcast Engineering
September 1986
www.americanradiohistory.com
A transformerless differential -input
stage can be driven from either a balanced or unbalanced source. When unbalanced outputs are used, the grounds
should be tied at the source. Tie the
signal to the differential inputs and leave
the grounds unconnected at the load.
This enables the common -mode rejection of the differential inputs to reject
any noise induced in the cable, even
though the source is unbalanced.
The only time input transformers are
needed is when there is a large amount
of common-mode voltage present or
when a specific terminating input impedance is needed, such as with telco
lines. Within the broadcast plant,
however, transformers are seldom required, and are actually undesirable. In
practice, the common -mode rejection of
a well -designed transformerless input
stage can easily exceed the best
transformer designs.
Transformerless output stages, however, require special attention when connecting to unbalanced loads. Many
balanced transformerless output stages
use two amplifiers, one for each side of
the line. If one of these amplifiers is connected to ground, which is what happens
in an unbalanced load, large short-circuit
currents can flow. At worst, this will
destroy the output stage. At the least, it
will cause increased distortion and
crosstalk levels. Unbalanced loads should
PR99 MKII
THE
BALANCED BUDGET ATR
fully professional, balanced in/out ATR that's priced perfectly for
broadcasters on a budget. Although compact in size, the PR99 MKII scores big on production features, audio performance, and long
term reliability.
The PR99 MKII is a
Help for Deadline Dodgers When
deadline pressure hits, the PR99 MKII
comes to your rescue with new microprocessor-controlled cueing and
editing features: A highly accurate
real time counter. Zero locate and
address locate to find your cue and
stop right on the money. Plus auto
repeat for timing and rehearsing. The
seconds you save will show in your
production quality ... and your blood
pressure. Other features include edit
mode, tape dump, self -sync, input
and output mode switching, input
and output level calibration, and
front -panel vari -speed. Console, remote control, and monitor panel
available as options.
It The Swiss -engineered
PR99 MKII has earned its reputation
for reliability. From the massive die-
Count on
cast chassis to the servo capstan
motor, every part is milled and drilled
to fit right and
stay put. For a
long time. Modular electronics sim-
plify maintenance
and servicing.
Pure Performance
Purity of sound reproduction has long been a
hallmark of Studer Revox
recorders, and the PR99 MKII
is no exception. Noise, distortion, and frequency response
specs rival those of recorders
costing far more.
All This for Not Much Competitively priced, the PR99 MKII carries
the lowest suggested list price in the
under-$2500 class. For more information, contact your Revox Professional
Products Dealer, Find out how easily you
can fit the PR99 MKII's balanced performance into your station's budget.
REVOX
Studer Revox America, Inc., 1425 Elm Hill Pike, Nashville, TN 37210/(615) 254-5651
Circle (17) on Reply Card
www.americanradiohistory.com
be driven from only one side of such a
balanced output driver. The other side
should be left unconnected. This configuration typically results in a level loss
of only 6dB.
Floating output drivers
There is a new kind of driver available,
called a floating output driver. It
operates like a transformer-coupled output in that it delivers the correct signal
level between the + and - output terminals no matter what kind of load is
connected, whether balanced or unbalanced. This driver has the additional
advantage of automatic adjustment of
the signal level so that if an accidental
short circuit takes place, shorting one
side of the line to ground, the shorted
output shuts down and the other side increases its output to deliver the correct
signal level without interruption or
distortion.
Single -level switching
The flexibility and productivity within
a broadcast facility can be increased
through the use of a central routing
switcher. This is a large switching matrix
to which all the sources within a facility
are wired as inputs, and outputs are provided in all the production areas. This
design allows any signal to be routed to
any location within the facility without
using a patchbay. There are even TV
master control switchers that use the
central switching matrix rather than a
separate matrix, making all sources
within the plant available to the operator
without patching or wiring changes.
Traditionally, when stereo signals are
distributed, two identical routing switchers are used, with one switching level for
the left channel and another level for the
right channel. Usually, any mono
sources or destinations are wired into the
left channel, although they could be
paralleled to both channels. This method
limits the flexibility of feeding mono
signals to stereo destinations, because
the switching levels are separate.
One way to simplify the central switching of audio in which stereo signals are
involved is to use single -level switching.
This is done by placing all audio signals
within a single level of the audio switching matrix. Both left and right channels,
and mono signal sources and destinations, are connected to the matrix.
The main advantage is that it is now
possible to do stereo channel reversals,
mono to left and right, as well as left -to
stereo and right -to -stereo feeds without
special outboard mixers or hardware.
With the addition of a few dedicated active mixing amplifiers, it is also possible
to do re-entry left and right to mono mixing within the routing switcher. Even
phase -reverse amplifiers with re-entry
could be accommodated. These features
greatly increase the flexibility of any
signal -distribution system and can be
built with current equipment.
-
32
Broadcast Engineering
TRADITIONAL METHOD
RIGHT CHANNEL
LEFT CHANNEL
30 LEFT INPUTS
10 MONO INPUTS
40 OUTPUTS
30 RIGHT INPUTS
10 MONO INPUTS
40 OUTPUTS
TOTALS: 32 10x10 MATRIX CARDS
8 OUTPUT CARDS
SINGLE -LEVEL METHOD
30 LEFT INPUTS
30 RIGHT INPUTS
10 MONO INPUTS
70 TOTAL INPUTS
80 OUTPUTS
TOTALS: 56 10x10 MATRIX CARDS
8 OUTPUT CARDS
single -level switcher, these
portions of the matrix provide the stereo
channel reverse features. They also increase the total number of matrix cards
required over two 40x40 matrices.
In an 80x80
40x40
LEFT
CHANNEL
40x40
RIGHT
CHANNEL
80 OUTPUTS
Table 3. Comparison of the number of matrix cards needed to build a single -level switcher and
a 2-level switcher. The single -level design is more flexible, but requires more matrix cards.
now possible using these and
The control of such a matrix can be accomplished in many ways. With the
system
sophisticated microprocessor-based
Many of these techniques have been
used in the recording industry for years.
Providing your TV audience with high -
systems available today, it is possible to
make the actual control of such a system
essentially transparent to the operator
using standard equipment.
One disadvantage of this system is that
it does require a single, large audio
switching matrix instead of two smaller
matrices. The large matrix may cost
more than the two smaller matrices, but
the larger matrix is a much more flexible
way to configure a system. Figure 7
shows how a matrix such as this would
be configured.
It should be noted that if mono mixing
is desired, some dedicated inputs and
outputs are required to feed an outboard
mixer with re-entry provisions to
develop the stereo-to-mono mix. The
same design would be required for phase
reversal. These features are optional,
however, and the basic features can be
configured in a straightforward manner.
Table 3 compares the two methods of
configuring a matrix. The design provides 10 mono and 30 stereo sources and
destinations and the switcher is constructed with a commonly available 10 x
10 matrix card.
The realization of a truly high-performance stereo audio signal -distribution
September 1986
www.americanradiohistory.com
is
other high-performance techniques.
quality audio is certainly worth the effort. In actual practice, when high quality transformerless systems are used,
the audio difference can be discerned
even on a 4 -inch TV speaker. Don't
short-change your audience. They can
hear the difference.
Bibliography
Standard: Publication 268-15, Sound System
Equipment, Part 15; Interconnection of Sound System Components; International Electrotechnical
Commission, Geneva, 1978; Section 2, Number 7;
"Connections" (cables); and Chapter 11, "Broadcast and Comparable Professional Use;" Section 4,
IEC
"Preferred Matching Values."
Hess, Richard L. "Voltage Transmission For Audio
Systems."
Audio
Engineering
Society Preprint
No. 1708(1-3). Presented at the 67th AES Convention, Oct. 31 -Nov. 3, 1980.
Burdick, Allen H. "A Clean Audio Installation Guide."
Benchmark Media Systems Inc., North Syracuse,
NY. Paper obtained from Benchmark Media
Systems.
Bytheway, David L. "A High Performance Differential
Line Transceiver." Professional Program Session
Record, WESCON 83. IEEE Student Journal, 1983.
Connally, Craig. "Contemporary Console Design and
Performance." Recording Engineer/Producer, Vol.
' :r4))))
II, No. 3, June 1980, pp. 60-67.
Almost
of recycled
materials. Cartridges eliminate "cue
burn" and provide hundreds of plays with
consistent audio quality.
You'll save money just by preserving the vinyl as a library
master. Cartridge machines are also
more durable, less subject to damage
and utilize less space than turntables.
half the United
States broadcast
industry has discovered the performance, operational and
cost advantages of recording
their critical audio
music ..
onto cartridges. Whether dubbing
from vinyl records or compact discs,
these broadcasters produce reel-toreel sound quality over -the -air and, at
the same time, experience all the
advantages of cartridges. Here's why
they, and we believe in music ..
you can too!
...
Call today to take advantage of
d
.
Quality Makes Carting
Music a Reality
International Tapetronics
Corporation/3M cartridge
machines and today's premium cartridges, such as
the ScotchCartt broadcast
cartridge, allow sound
reproduction with virtually
no audio degradation.
carting music on ITC's complete line
of cartridge machines.
99B Cartridge Machines, "The Best"
DELTA Cartridge Machines,
"Today's Most Popular Cartridge Machines"
OMEGA Cartridge Machines,
Affordable Performance
You Can Trust"
When newer technology
emerges, it will come from
International Tapetronics
Corporation/3M, "The Leader
in Reliability and Service."
it
Easier to Use
Unlike vinyl records, compact discs
or reel-to-reel tapes, cartridges automatically recue after each play.
Cartridges can also be easily preloaded
into multiple machines providing valuable extra time for announcers. Plus,
labeled cartridges are easier to read,
file and locate.
Flexible Programming with Less Errors
An all -cart format reduces operator and
format errors, such as playing the wrong
cut off an album, compact disc or reel-toreel tape. It also allows prerecording and
editing of program segments facilitating
precise program control.
Sound Better and Save Money
A vinyl record played 40 times loses
its sound quality, especially when made
In the U.S. call Toll Free 800-447-0414,
or collect from Alaska and Illinois
309-828-1381. In Canada, call Maruno
Electronics, Ltd. 416-255-9108. In most
countries outside the United States and
Canada, information on ITC equipment
can be obtained through local
distributors.
International Tapetronics Corporation/3M
2425 South Main Street
P.O. Box 241
Bloomington, Illinois 61702-0241
3M hears you ...
See us at Booth #538/601
at the SBE National Convention in
St. Louis, MO 10/14-10/16/86!
Circle (19) on Reply Card
www.americanradiohistory.com
3M
Panasonic®brîngs YOU M-111
The broadcast recording system our
competition can't seem to duplicat&
- ..--
.y.R..-.
-_ `-
__.. ._._ ---- .
.--.---r-r.
=`-==
....,.-.
-=
www.americanradiohistory.com
Now you can shoot. edit
and broadcast with 1" quality on 1/2" cassettes.
When it cores to broadcast systems, it aptioeers
our cornoetition nas bee/ erased. Because ro
other format can match the spectacular perforrrance of 'V!-11 from Panasonic.
With 41 -i's metal partece tape slste-n, you can
;se the same compact GO- or pocket-size 20-me' _te cassette from ENG. EFP right trough e,dìtrn.q to
on -air troadcast. With 4.5MHz ba,idwidth
. OdB SiriN and bJrst signal insert.on fc. phase
alignment and Biter correction, M-2 is the single
solution 'c all your broadcast neesss.
In fact each unit in the M-17 line cffers some
pretty urcomnron common features like four audio
tracks (two linear and two FM), an latecral longiauoinal and vertica, Interva' time cooe%tir'e date
generator wits oresettab'e user bis ar.d Golby--C
noise reduction. And M-77 F,roducts utirze a
standard edit control i.nterfece, se you car
upgrade eradual;y if you like.
AU -650 Studio VCR. The compact.
rack-mounta:Je VCF: has al; the advantages and unctions of
corventionar recorders Nit)
the beneFt of the M -H format. The AU -550 provides
video and audio performance as gcoo' as-if not
better than-that of 1" VTRs. 'n a 1' cassette format
that lends itself to station automation. it records and
plays either 90- or 20 -minute cassettes, and propices smooth action, variable slow notice es wail as
freeze frame. And the AU -650 can perfore frameac :urate automatic editing with multi -generation
transparency. There's also an interna.' TBC to assure
on -air quaity playback.
A1.-500 Field Recorder. The AU-500 oilers the po-±atility and functions demanaed by E."J'3; EFP users,
wfle providing picture quality compareove to 1"all on either a 90- or 20 -minute cassette. This srra'l,
ruçgedly designed unit is equipped with confidence
refd color payback, automatic backspace editing
BiDOC connection, search functo. and warning
inculcators that alert the opera'or shot.id recording
prcblems arse and the AU -500 acco.-rrodates
,"JTSC composite or various component 'neat s;gnats.
The AU -409 Camera Recorder. This igrtvweignt,
compact camera recorder provides ENG users with
m, ore than 20 minutes of recording, and a picture
quality that rivals that of 1" VTRs. The rU-400 also
features B/W video confidence playback ±'trough the
camera's v:ewfinder, a chroma confidence indicator
and audit confidence output through a speaker.
There's even an automatic backspace editing function and warning ind;cªters. And
tne AU -400's ruggea const, uc.icn provides
excellent resistance to dust and moisture.
M -H, it's the only broadcast system of
its type in the industry. Arp it's evaiaable
now Two of the best teasers to go watt"
.a
le.
M-77
from Panasonic.
To get the complete picture, call or
write Panasonic Broadr.ast Systems
Company, One Panasonic Way,
Secaucus, NJ 07094. (2ü7) 348-7671.
THE NEW STANDARD
FOR BROADCAST.
Circle (2)) on Reply Ceri
www.americanradiohistory.com
Planning for TV stereo
By Douglas Dickey
Planning for a new console involves more than counting
up the number of knobs you think you'll need.
Today's LSf chips make complex modules,
such as the combination input/output
module, small and versatile.
When
it comes time to specify and install a new audio console, you and your
staff can look forward to an exciting experience. You can also expect it to be
one of the more problematic projects
you'll ever undertake. Careful selection
and proper installation of a new console
is a highly visible accomplishment for a
radio or TV engineer, and one that will
be appreciated by your colleagues for
years to come. On the other hand, an inadequate system or an unstable installation will be a constant irritant and a
source of wasted time for the entire production staff.
Fortunately, there are many excellent
consoles available today. Some of these
have features found formerly on only the
largest multitrack recording consoles.
For instance, it is no longer uncommon
for both air and production consoles to
incorporate sophisticated audio processing such as dynamics control and
parametric equalization and multiple
output groups. Although once considered unnecessary or extravagant,
such facilities are increasingly in demand
by today's broadcast operators. Their integration within the console can speed
and simplify installation and operation.
One area receiving considerable attention these days is multichannel television
sound (MTS). Both the producers and the
consumers of TV programming are demanding more creative and sophisticated soundtracks, and greater audio
quality. As TV engineers across the country are discovering, the stereo transition
involves a separate level of complexities
Dickey is vice president of design communication,
Solid State Logic, Oxford, England.
36
Broadcast Engineering
that are beyond the problems of distribution and transmission.
The competitive station must not only
be capable of distributing stereo audio
throughout the broadcast plant, but also
must have stereo production capability.
Moreover, it must achieve stereo quality
matching that from the network. TV
audio engineers are finding out this is not
an easy task.
Stereo audio on its own is far more
critical and less forgiving than monaural
sound. The marriage of multichannel
sound and TV pictures is an even more
difficult process. Add the requirements
for mono compatibility, and the fact that
the existing audio chains of many TV
facilities have been largely neglected for
years, and the scope of the task begins to
become clear.
On top of all this, ways must be found
to handle stereo production in roughly
the same time frame as is presently
allowed for mono. Otherwise, production costs will rise, program output will
slow, and the nationwide transition to
stereo will stop dead in its tracks.
Conceptually, the key to these problems is simple. The increased technical
and creative requirements of MTS must
be matched by gains in operation ease
and speed. In other words, the TV audio
plant must be optimized for both artistic
flexibility and engineering efficiency. In
practice, this achievement involves
many different disciplines.
The cost of achieving full recordingstudio acoustics can range from $50 to
more than $100 a square foot. This price
does not include the cost of the basic
structural shell. Although this expensive
approach may be unnecessary or impractical in many situations, there are a
number of acoustic elements to consider
before you wire up that new console.
Air-conditioning systems are the most
common offenders. To reduce the noise
pollution, compressors and blower units
can be decoupled from the main building
structure with isolation mounts. The
noise of moving air can be reduced by increasing duct volume and reducing
blower velocity. Broadband noise leaking in from the outside world can be
minimized by replacing the seals around
doors and windows and by adding
soundproofing at cable entrances and exits. Crew noise within the studio can be
reduced by adding absorptive materials
in off -camera areas.
These are all minor points, but their effects are cumulative. It is worth it to
track down and correct as many problems as you can. A number of electronic
fixes are available, but all of them will
repeatedly cost you time and money
later in the production process. Your
goal should be to ensure that all
Figure
1. Reducing air-conditioner noise can
be difficult. Note the difference in noise
generated by various types of fan blades.
60
'r-" a...
Studio acoustics
Unlike transmitter conversion, upgrading production facilities for stereo is a
process that can take place over a long
stretch of time. A good place to start improvements is in the studio itself. The
value of proper acoustics is too often
overlooked in the rush for the latest
equipment. Yet, if the goal is efficient
operation and a clean output, the importance of a trouble -free and easily
manipulated input is obvious.
The basic goals should be to eliminate
unwanted noise, to reduce or eliminate
leakage or acoustic crosstalk into the
various microphones on the set, and to
capture a natural and appropriate blend
between the direct and the reflected (or
ambient) sound present on the set.
September 1986
www.americanradiohistory.com
j\\\
-.4.430
0
125
63
250
500
1k
2k
4k
FREQUENCY (IN HERTZ)
LEGEND
-- ---
- --
CENTRIFUGAL FAN
CENTRIFUGAL FAN
CENTRIFUGAL FAN
---CENTRIFUGAL
FAN
- AIRFOIL BLADES
- BACKWARD-CURVED BLADES
FORWARD-CURVED BLADES
RADIAL BLADES
TUBULAR CENTRIFUGAL FAN
Microprocessor
control, amorphous metal
core heads,
and superior
performance .. .
technology
that's typically
AEG.
Chances are that the
M-21 Professional
Audio Tape Recorder
from AEG will outperform whatever 2 -Track
you're currently using
or considering for
future purchase. No
other machine is built
to such exacting standards, no other machine
handles tape as gently
yet rapidly, and no
other machine is
presently available with
Amorphous Metal
Butterfly Core Heads.
(Ours are standard
equipment; ask about
our exclusive head
warranty.)
The M-21 is micro-
self-contained package
with no external power
supplies or cabling,
and access to all
components for maintenance and alignment
is quick and easy. The
performance specifications are unexcelled.
It's only natural that
the M-21 should be
such a fine machine.
After all, we invented
In Canada:
AEG BAYLY INC.
167 Hunt Street
Ajax, Ontario L1 S 1P6
(416) 683-8200
In U.S.A.:
-
AEG Corporation
Route 22
Orr Drive
P.O. Box 3800
Somerville, NJ
08876-1269
(201) 722-9800
the modern tape
recorder over 50 years
ago. To arrange for a
free demonstration at
your facility, or for
information on any of
our other high technology products,
please give us a call.
processor controlled
AEG
and user -programmable for any 2 of 4
speeds. It is a totally
Circle (21) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
37
music applications and some ENG applications, stereo microphones are a
valuable tool. One especially useful
stereo micing technique is called the
mid -side (M -S) recording process. It is
1"
described in the related article, "M -S: A
RUBBER OR NEOPRENE
STRIPS
%" POLISHED PLATE
GLASS
318" POLISHED PLATE
GLASS
MINERAL FIBER
ABSORBENT
g
OVER CLOTH7
bh
Figure 2. Typical control room window construction.
microphone signals arrive at the console
as clean and natural as possible.
Ambiance
A properly constructed stereo mix will
Special Case."
Unfortunately, the technique of effective stereo microphony is extremely
dependent on the positioning of the mics
in exactly the right place. Even in the
world's great concert halls, finding this
place can take hours. In many TV
studios, it doesn't even exist-or if it
does, its location gives the lighting director insurmountable problems. For practical as well as aesthetic reasons then,
multiple mono pickups will continue to
be the norm for stereo production. The
stereo image will be created at the console through the use of panning and
special effects devices.
The greatest potential problem with
multiple microphones is that of phase
cancellation due to off -axis leakage between mics. This can result not only in
an unnatural sound quality, but in the
resurgence of interest in stereo
complete disappearance of certain audio
frequencies to the monaural listener.
Proper studio acoustics will greatly
minimize the likelihood of this occurring,
and increase your working flexibility.
microphones because of their capability
to capture this. For elements such as
crowd and audience sounds, certain
The audio control room must provide
convey not only a sense of left -to-right
panorama, but a front-to -back depth and
even a sense of height. There has been a
Control room acoustics
D
D
D
PLAN
ELEVATION
Figure 3. The control room must provide
a reference listening environment that
allows the recording engineer and other
production staff members to make accurate judgments about a program's
audio content. One requirement imposed
by stereo is the need for control room
symmetry. Surfaces with dissimilar
Continued on page 42
CHASER
The new Generation of Synchronizers
designed for precision audio/video tape interlock
Worldwide sales and service support
LEVER,TZ
EVERTZ MICROSYSTEMS LTD.
Head Office: 3515 Mainway. Burlington. Ontario. Canada L7M 1A9
Telex: 061-8784 Telephone: (416) 335-3700
Visit us at SM PTE Booth 868
Circle (22) on Reply Card
38
Broadcast Engineering
September 1986
www.americanradiohistory.com
a
stable stereo image, free from frequency
response and reverberation aberrations.
More power for the
voice of freedom.
High Power SW Transmitters
The Marconi Advanced PULSAM p.w.m. system
makes our latest high -power short-wave transmitters over 10% more energy -efficient than any
previous design. And when you're producing
1 megawatt of power continuously, that's a very
substantial saving.
Naturally, these transmitters provide superb performance (with very tlow levels of spurious radiation).
They offer low maintenance costs thanks to outstanding reliability and dual source components.
They provide failsafe protection for equipment
and personnel.
And they share with their predecessors a unique
degree of designed -in reliability to ensure that the
www.americanradiohistory.com
message from the free world comes through loud
and clear.
For more details contact, Marketing Dept., Space
& Broadcasting Division. Marconi Communication
Systems Ltd, New Street, Chelmsford, England
CM1 1 PL. National 0245 353221. International
44 245 353221. Telex 99201. Facsimile (Gp 2/3)
0245 87215
Circle (23) on Reply Card
Marconi
Communication Systems
TIE FURTIER WE GO, T
'
-
. `Il, ,!f}.
`(:`.1[.Nt : r T¡-`, `ñi^.,!`l
v:
//'/,i'lrl:5 //u/Sl ¡ii,(;rfia,l l,uf)(:; Íur' r'r.ü.l'i,and
_T
.-'º.
T
...
.
Belgique:
BRUXELLES
Tel (32 2) 648 64 85
Tx
23113 THBXL
B
xi
-
._
f
.
'
...
.
..
.
í'-
r s-
iv
F
et-
Brazil:
SAO PAULO
Tel (5511) 542 47 22
Tx (011)
.
24226
TCSF BR
,
Canada: MONTREAL
Tel (1514) 2884148
'E`v
-.
'
OUEBEC
Deutschland:
Tel
Tx 560 248 TESAFI MTL
www.americanradiohistory.com
5
dcasting.
t
Tx
MUNCHEN
(49-89) 7879-0
522916
CSF D
España: MAORIO
Tel (341) 4051615
Tx
46033
TCCE E
Frana:
BOULOGNE-BIlLAN000RT
Tel (33-1) 46 04 81 75
Tx
THOMTUB 200 772
F
FURTHER YOU GO.
At Thomson-CSF we've been
pioneers is developing the use of
high power tetrodes in transmitters for more than 70 years.
Over the years we've stayed
ahead with such developments
as Pyrobloc® grids and the
Hypervapotron® cooling system.
We offer: a complete line of
tubes for radio broadcasting
applications from FM to the
most powerful SW and LW
transmitters - the quality of our
500-600 kW tubes has been
amply demonstrated in 15 years
of service in over forty transmitters worldwide.
A complete line of power grid
\ktubes and their associated cavities
(life UHF/VHF TV transmitters.
Thanks to their efficiency, reliability and,tight tolerances, systems
makers can offer their customers
it substantially more cost-effective
products.
A complete line of klystrons
%-titknd TWTs for ground stations and
space TWTs for direct broadcasting satellites (DBS) designed to
last for at least a decade.
And we also produce high resolution image pick-up tubes
and devices (CCDs), and high luminosity CRTs for top range
professional applications.
In radio and television, telecommunications, military and civil
aviation, as well as in a wide range
of scientific and medical applications, Thomson-CSF know-how
gets your systems moving. Fast.
4
UHF and
VHF tetrodes up
to 50 kW.
-
Matched cavities
for best results.
C
--
'
High power
radio broadcasting
1-
11111M
tetrodes up to
1.2 MW
(including
the famous
SW/ LW tetrode
11111Mie
delivering
500 kW/600 kW).
VIII
Earth station tubes up to
18 GHz (1.5 kW)
(6 GHz).
or to 3.35 kW
High efficiency space TWTs
(including 40 W/50 W Ku -band for
next generation DBS Satellites).
Wifirm.'
:N THOMSON-CSF
ELECTRON TUBES
Primicon high-resolution, no -lag TV camera
pick-up tube.
e
THOMSON ELECTRON TUBES AND DEVICES CORPORATION
550 Mount Pleasant Avenue
DOVER, NEW JERSEY 07801.
Tel.: (201) 328-1400.TWX: 710987 7901.
Circle (24) on Reply Card
li)
I
Italia:
Tel
Tx
Japan:
ROMA
(396) 639 02
I
Tx 2
Sverige:
TOKYO
Tel (81.3)
48
620683 THOMTE
2646346
324 241 THCSF
Tel
J
TYRESO
(468) 7428010
United-Kigdow:
BASINGSTOKE
Tel (44256) 29155
858865 TESAFI
U.S.A.:
DOVER
Tel (1-201) 3281400
TWX 710987 7901
www.americanradiohistory.com
Tx
G
l
ir
o
VID VIDEO
0 -FRAME OFFSET ADDRESS
TRACK MODIFICATION
Update all VO -5850,
VO -5800, VO -5600,
VP -5000, VO-5630P,
VP -5030 with SMPTE time
,
2
3
4
5
6
7
6
A
6
c
mc
.10
code
.90
TRIM
l 0
Allows third channel time
code capability
-I0
Head switching to 21/4
H/V sync
0
10
a..4
5
2
BVU-800 compatible
VID VIDEO installed or
installation kits available
3.5
QlT
kDi-
IN
3
120
70
._.20
300
20
And now also for the
VO -6800
OUT*
350
/-1h
INSERT-DIRECT 0/P
DIM
mu i-E1
11111111111111111s
Ille
4
Figure 4. Typical input modules provide a
selection of several inputs, phase reversal and
SHUTTLE
new remote controller
Adds shuttle knob to
VP-5000/VO-5600,
VP-5030/VO-5630P
Allows same control as
VO -5800 or VO -5850
Variable speed
to 5x in
forward and reverse
Great for logging time
code numbers
Control track readout/
preroll
A
-0
SHUTTLE II
A new interface box
Allows use of VP -5000 or
VO -5600 with: RM -440,
ECS-90, ECS-204
Saves $2,000 per playback
VTR
o
di%I
-0
Variable speed
to 5x in
forward and reverse, and
bump commands from
edit controller
Contact: Russell W. Glenn
Servid Manager/Owner
Former Sony Broadcast Instructor
3919A W. Magnolia Blvd.,
Burbank, CA 91505
(800) 826-2035.
In California (818) 845-1515
gain trim controls. The I/O module on the left
provides two line -level inputs. The one on the
right provides both line and mic inputs.
Continued from page 38
properties on either side of the recording
engineer can cause errors in judgment.
Control room acoustics should provide a
stable stereo image across as wide an
area as possible.
Equal attention should be given to at-
Console selection
Assuming that all the practical steps
mentioned have been taken to provide
clean audio sources and accurate audio
Figure 5. Today's consoles often provide individual channel equalizers like the one
shown below left.
uniform decay times across the
operator's position. If production staff
members involved in the creative audio
judgments will be sitting behind the
recording engineer, you should ensure
that the sound they hear is as similar as
possible to that at the mixer's position.
One frequently overlooked element is
the effect the console itself can have on
the control room acoustics. In fact, all
control surfaces and equipment racks
can affect the room's frequency response
as well as the decay time as measured at
the listening position. A balance must be
struck between the operator's needs, the
technical facility requirements and the
acoustic implications of these decisions.
Each of these aspects should be considered in control room layout.
Control room monitors
In addition to
the primary control
room monitors, it's extremely useful to
have one or two alternate speaker sets
and the capability to easily switch between them. This technique allows the
recording engineer to compare the spectral balance of the mix on different
speakers. It also allows the mix to be
judged on speakers located at different
distances from the listening position.
Broadcast Engineering September 1986
www.americanradiohistory.com
/\30
ED
OMono
taining smooth frequency response and
Circle (25) on Reply Card
42
By mentally averaging the perceived
differences, the engineer can arrive at an
optimum balance-one that will sound
just fine to the audience. The majority of
TV viewers will be listening in mono for
at least the next few years, so it also must
be easy for the engineer to switch between stereo and mono listening.
It is worthwhile to connect a phase
scope or phase meter across the main
stereo program outputs. The scope
display or meter provides a visual indication of the signal's phase. This is especially important if you are monitoring in
stereo, which makes it easy to misjudge
the phase compatibility of the mono mix.
The phase meter or scope will help prevent the broadcast of a phase -reversed
signal that can't be heard by the majority
of your audience.
If you plan on using the second audio
program (SAP) channel, some additional
monitoring provisions usually are required. If, however, the SAP is always
created in post-production, additional
monitors may not be needed. You may
want to be able to insert a filter in the
monitor chain to simulate the SAP's
reduced bandwidth. This option allows
you to equalize the mix to compensate
for the SAP's frequency limitations.
0
B.
3
-0-
9
12
,
1.2
-IS o .15
HF
I
is.5
.e ma
Wt.
HnF
9-
i2
12
-IS ®
2.j,.3
415
1.]II
LnF
S
T!
3.0
G.
115
-15
R:
3
.O
ie .15
inaQ
.1S
LF
t
ti
-15
-o.12
as '15
OS
193
'
,5.
275
325
.,53
Hz
o
Figure 6. When live music or voice production is required, compressors, limiters and
noise gates are useful devices to have built into your console. A typical compressor/expander is shown above right.
T1UTH...
If
OR
CONSEQUENCES.
you haven't heard JBL's new generation of Studio Monitors,
you haven't heard the "truth" about your sound.
TRUTH: A lot of monitors "color" their
sound. They don't deliver truly flat
response. Their technology is full of
compromises. Their components are
from a variety of sources, and not
designed to precisely integrate with
each other.
CONSEQUENCES: Bad mixes. Re -mixes.
Having to "trash" an entire session. Or
worst of all, no mixes because clients
simply don't come back.
TRUTH: JBL eliminates these consequences by achieving a new "truth"
in sound: JBL's remarkable new 4400
Series. The design, size, and materials
have been specifically tailored to each
monitor's function. For example, the
2 -way 4406 6" Monitor is ideally
designed for console or close -in listening.
While the 2 -way 8" 4408 is ideal for
broadcast applications. The 3 -way 10"
4410 Monitor captures maximum spatial
detail at greater listening distances. And
the 3 -way 12" 4412 Monitor is mounted
with a tight-cluster arrangement for
close -in monitoring.
CONSEQUENCES: "Universal" monitors,
those not specifically designed for a
precise application or environment,
invariably compromise technology, with
inferior sound the result.
TRUTH: JBL's 4400 Series Studio Monitors achieve a new "truth" in sound with
an extended high frequency response
that remains effortlessly smooth through
the critical 3,000 to 20,000 Hz range.
And even extends beyond audibility to
27 kHz, reducing phase shift within the
audible band for a more open and natural sound. The 4400 Series' incomparable high end clarity is the result of JBL's
use of pure titanium for its unique
ribbed-dome tweeter and diamond
surround, capable of withstanding forces
surpassing a phenomenal 1000 G's.
CONSEQUENCES: When pushed hard,
most tweeters simply fail. Transient
detail blurs, and the material itself
deforms and breaks down. Other materials can't take the stress, and crack under
pressure.
TRUTH: The Frequency Dividing Network in each 4400 Series monitor allows
optimum transitions between drivers in
both amplitude and phase. The precisely
calibrated reference controls let you
adjust for personal preferences, room
variations, and specific equalization.
CONSEQUENCES: When the interaction
between drivers is not carefully orchestrated, the results can be edgy, indistinctive, or simply "false" sound.
TRUTH: All 4400 Studio Monitors feature JBL's exclusive Symmetrical Field
Geometry magnetic structure, which
distortion, and is key in producing the
4400's deep, powerful, clean bass.
CONSEQUENCES: Conventional magnetic structures utilize non-symmetrical
magnetic fields, which add significantly
to distortion due to a nonlinear pull on
the voice coil.
TRUTH: 4400 Series monitors also
feature special low diffraction grill frame
designs, which reduce time delay distortion. Extra -large voice coils and ultrarigid cast frames result in both
mechanical and thermal stability under
heavy professional use.
CONSEQUENCES: For reasons of economics, monitors will often use stamped
rather than cast frames, resulting in both
mechanical distortion and power compression.
TRUTH: The JBL 4400 Studio Monitor
Series captures the full dynamic range,
extended high frequency, and precise
character of your sound as no other
monitors in the business. Experience the
4400 Series Studio Monitors at your JBL
dealer's today.
CONSEQUENCES: You'll never know
the "truth" until you do.
JBL
dramatically reduces second harmonic
IBL Professional
8500 Balboa Boulevard
Northridge, CA 91329
Circle (26) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
43
MICROPROCESSOR
CONTROLLED KLYSTRON
HIGH POWER AMPLIFIERS
SATCOM C-Band/Ku-Band
The versatile Klystron Amplifier line
Series 10000 is field -proven, constructed for long life, easy access,
with solid state power supplies and
a host of other needed, tested,
exclusive features. The Klystron
Amplifier shown is M/N 106673.35KW C -Band high gain with
microprocessor interface, the latest
in the continuously evolving line of
MCL's State -of -the -Art Satcom
transmitters. Options include the
M/N 13049 microprocessor controlled Channel Selector unit.
Used throughout the world, the
desirability of MCL microwave
transmission equipment constantly
grows. This includes Satcom C and KuBand TWTA's (75W-3KW),
instrumentation TWTA's Satcom
and instrumentation KPA's and
coaxial low frequency transmitters.
MCL assures you of 24 hour
maximum parts replacement; provides 24 hour
day access to
MCL personnel for assistance in
installation or servicing.
-7
New for 1985: solid state beam
regulation option.
WRITE for your complimentary
copy of Reference booklet #1001
TODAY.
INC
A".
MCL, INC., 501 S. Woodcreek
Road, Bolingbrook, IL 60439-4999
(312) 759-9500
TWX
910-683-1899
Circle (27) on Reply Card
44
Broadcast Engineering
September 1986
www.americanradiohistory.com
monitoring, the next step is to use
suitable technology for stereo audio mixing. The production equipment must be
evaluated, not only in terms of capacity
and creative flexibility, but also in terms
of operational speed. Although the mixing console is the single most important
element, the twin goals of quality and efficiency dictate a close look at the ways
various audio control room elements
work together. Machine control, effects
processing and mixing automation may
all be part of your total system.
Consider that the audio console must
handle greater numbers of both mono
and stereo sources than ever before.
These sources must be combined into
mixes that convincingly match the picture perspective in both stereo and
mono. To accommodate the SAP, the
sources also must be divisible into splits
such as dialogue, music and effects, and
these must also be available in both
stereo and mono. In addition to various
mix-minuses to feed the talent and production foldback lines, auxiliary sends
must be provided to the various effects
devices, which will be used to reinforce
the illusions of space and perspective.
Input controls
For mono input channels, the
minimum controls should include a
mic/line switch, a line -trim control, a
mic pre -amplifier gain control and a
phase -reversal switch. For maximum efficiency, stereo inputs require additional
controls. An input balance control for
trimming the left and right channels
should be provided, along with phase reversal switches for both left and right
inputs. The console should also be able
to direct either the left or right signal to
both sides of the mix bus or to feed the
L+ R signals to both sides of the bus. For
stereo microphone sources, provision for
converting the mid -side (M-S) encoded inputs to standard left and right signals is
also a desirable feature.
Signal processing
Following these input controls, both
the mono and stereo channels should be
equipped with some signal-processing
capability. This should at least include
high- and low-pass filters for cleaning up
rumble and hiss. Flexible equalization is
also required to fine-tune each source in
relationship to the others. Many console
manufacturers now provide 4 -band
equalizers on their broadcast consoles.
Although this may seem to be overkill, it
has the advantage of allowing two
overlapping bands in the mid -range
areas, which are critical to speech intelligibility. This feature is well worth the
price in complex mixes.
A switchable patch point that allows
outboard gear to be inserted into each
channel path is another useful feature.
Some manufacturers have taken this approach a step further by including a
switchable compressor/limiter on each
The Breakthrough!
I
KEGAM I'S HK-323 1 " FIELD/STUDIO BROADCAST
CAMERA BEGINS A NEW ERA
Ikegamis newest field/studio broadcast
camera achievement has arrived-
engineerec and designed to provide the user
with features beyond expectations.
The HK -323 1' features self-contained
operation, numerous auto set-ups in any
mode, a built-in encoder and sync generator,
high perfo-mance prism optics, self -diagnostic functions, a control panel that connects directly to the camera head, a S. N ratio
of 59dB and more-all in a camera weighing
only 55 lbs
In add tion, the HK-323 1,' is equipped
with a 7" viewfinder featuring pan and tilt, and
special functions that include Chroma Aperture for sha -pest picture quality regardless of
color or lighting; Highlight Compression Circuitry for boadcast contrast range; Soft Detail to eliminate harsh or overwhelming
presence; Auto Beam Control, and more.
A companion hand-held camera is also
available and is operational off the same
base station.
Optional remote control is available in:
triax, multicore and fiber optics.
Compare the HK-323
to any camera
in its class and find out why the lightest
field/studio zamera is also the biggest value.
For a complete demonstration of the
HK -323 1"' and other Ikegami cameras and
monitors, contact us or visit your local
Ikegami dealer.
1
Ike' mi Electronics (USA Inc. 37 Brook Avenue Maywood, NJ 07607
E.
oast: (201) 368-9171 West
st: (213 534-0050 Southeast: (813) 884-2046
4 Midwestf'(312) 8, 4-9774
thwest: (214) 23
Circle (28) on
¿
Card
www.americanradiohistory.com
to a cleaner mix.
Auxiliary sends
upI.
"
ovr
Auxiliary sends are used not only to
provide foldback to the talent and the
production crews, but also to feed special
effects devices. Each local send control
should provide on/off switching, level
control and the capability to select its
source either pre- or post-fader. The
number of required mono and stereo
sends varies between applications. Usually, a minimum of four mono sends is required. Some productions need as many
as eight or 10 mono and stereo sends.
INSERT
Group outputs
addition to auxiliary sends, a
number of group outputs should be provided. For the sake of manageability, it is
often useful to combine numbers of
In
The creation of shooting logs
on location has never been
easier. Comprehensive's
LOG-ITTM 100 Program transforms your 41/2 pound,
battery -operated Radio
Shack® Model 100 computer
into a time code reader and
tape logger that can be used
anywhere. With the stroke of
a single key, LOG-ITTM 100
automatically reads SMPTE
time code at up to 6 times
play speed in forward and
reverse. A built-in programmable stop watch even lets
you log control track tapes.
0
0
microphones into common
iaoJ
7. Auxiliary send
channels provide an extra
measure of flexibility in
live-mixing situations.
Figure
The LOG-ITTM 100 program
is supplied on a plug-in cartridge. No additional hardware, special tools, or modifications to the Model 100
are required.
Control groups
,
For more information call
Comprehensive toll -free at
1-800-552-2CAV.
ui.o
.d
..... J
LOG-Ir 100
Rado Shack is a registered trademark of Tandy Corp.
Figure 8. Typical console
module assembly.
(rxcIñnfÎ
C o nn
VIDEO
SUPPLY CORPORATION
148 Veterans Drive
Northvale, New Jersey 07647
(201) 767-7990
Broadcast Engineering
O
channel. This approach has the advantage of allowing rapid and precise control over the dynamics of each channel.
Some consoles also include noise gates,
which can be used to automatically close
an input channel in the absence of a
signal. This automatic switch contributes
Circle (30) on Reply Card
46
audio
subgroups. For example, the individual
levels of several audience mics may have
their outputs routed to a common audio
group. This group's fader is then used to
adjust the overall level of the audience
microphones.
Group outputs may also be used to
route individual elements to one or more
channels of a multitrack tape machine.
This allows you to create a multitrack
backup tape of a live event, or to build a
multitrack master in post-production.
This master tape can then be used to
develop the final mix. As a general rule,
a minimum of four or eight audio subgroups should be provided. If extensive
multitrack work is anticipated, 24 or 32
group outputs may be required.
September 1986
www.americanradiohistory.com
Several manufacturers offer control
groups, also known as VCA (voltage controlled amplifier) groups. This feature
allows common level control over a
number of channels while maintaining
their independent audio paths. For example, you might want to individually
route the various orchestra microphones
to separate multitrack channels and to
different split feeds. At the same time, it
might be necessary or desirable to control the overall orchestra level with a
single fader. This type of control makes
live mixes more manageable.
This feature can't be accomplished by
audio subgrouping, because that requires
all sources to be grouped to a common
bus. Control groups, on the other hand,
simply place the control voltages for
each element's fader under the control of
a master control group fader. If you anticipate productions involving 20 or
more channels, some sort of control
group scheme will prove to be worth its
weight in gold.
Splits and submixes
In some post -production applications,
the stereo TV industry is borrowing the
film technique of creating separate
music, dialogue, effects and ambiance
Born To Broadcast.
Introducing Ampex 198 and 199 1/2"
Professional Broadcast Videocassettes.
Our 198 and 199 are everything you asked
for in 1/2" broadcast videocassettes. Because
we listened to you before we created them.
You told us you wanted bright, sharp
color and clean, crisp pictures. Pictures with
fewer dropouts. So we created an advanced
high energy formulation and manufactured
the tapes in a state-of-the-art cleanroom
environment using anti -static materials.
You told us they had to be rugged
and durable. So we created a
tough tape binder system and a
precision -molded, high -impact
ABS plastic cassette mechanism.
But we didn't stop there. We also created
a user-friendly labeling system that helps you
find material fast. Because you don't have
time for delays in the ec itiig suite.
The result is everything you asked for in
the newsroom, on locati Dr and for automatic
cart playback systems.
Ampex 198 and 1991,'2 ' videocassettes
in Betacam'° or M forma}. Great color.
Great pictures.
AMPEX
M
One of The Signal Comparnes3
Ampex Corpcxaton, Magnetic lape Division.
401 Broadway Redwooc C
CA 94063.415,367-3ö09
Ampex Corporation
Circle (29) on Reply Card
www.americanradiohistory.com
Microdyne presents
the first automatic
satellite program shifter.
N.T.U.
APITMS
Bus.
Watch
H.S.N.
MAT: Microdyne Automated Terminal
Now you can take full advantage of the wealth of programming available via C- and Ku -
Turns on, tunes up,
automatically.
M.A.T.'s system clock automatically turns the system
on and tunes in the programming you want for any
particular day and time.
You can set it for one proM.A.T.'s
Rely on
gram, or a succession of
memory instead of
.._.,,
l
programs,
for as long as you
your own.
want. It even controls descramM.A.T.'s microprocblers, video recorders or other
essor stores hundreds of program
external equipment. And you
pre-sets-satellite position, can operate M.A.T. through its
signal polarization, transponder
own front panel keypad or by
format and frequency. Once
remote terminal.
M.A.T. is programmed, subse-
band satellites with the only
TVRO system that's as easy to
use as a home VCR.
quent reception is push-button
easy. You enter a simple program
code and M.A.T. does the rest,
right down to peaking its motorized, high -resolution fiberglass
antenna.
M.A.T. And you can have the
flexibility and unlimited program
access of M.A.T. for under
$20,000, installed. Options include a 5 or 7 meter antenna to
meet the stringent requirements
of
broadcasters and cablecasters.
Installed and backed
by Microdyne.
M.A.T. is built, installed, and
backed by Microdyne, a company
committed to exceptional reception and service since the beginning of satellite communications.
Call (904) 687-4633 or write for
more information today.
Economical base price,
broadcast quality options.
No other satellite TVRO system is available anywhere, at any
price, with the capabilities of
Circle (31) on Reply Card
www.americanradiohistory.com
Microdyne Corporation
491 Oak Road P.O. Box 7213
TWX: 810-858-0307
Ocala, FL 32672
mixes. By dividing the total mix into
separate submixes, it becomes much less
expensive to subsequently create
specialized mixes. For example, a
Spanish language version of a program
could be easily developed by simply
replacing the English dialogue with
Spanish. Only the dialogue would need
to be remixed and then combined with
the existing music and effects mixes.
Unlike film, television often has to
Exclusive, triple patented dynamic
cap and coil analyzing ... guaranteed
to pinpoint your problem every time
or your money back
RarypEs
meet these complex production requirements in real time. Live broadcasts and
live -taped productions are examples of
complex feeds. Separating the audio into
individual feeds or splits is often the only
feasible way to control all of the audio
elements.
0Q
.N
4 LCT
.R
MODEL
,NGE
CRPRp7Dlly RpyC,
varcE
mN
n
RRRlY2lR
Cnv4CZGMETER=
."
RiNGER
iMCEGNNCE
NRTCN
Typical console mixes
One manufacturer's console allows
each channel and audio subgroup to be
routed to three stereo mix buses
designated A, B and C. On mono channels, stereo panning is provided between
the left and right channels of the selected
bu& On stereo channels, image width
controls allow the engineer to correct
the perspective of prerecorded materials
to better match the picture.
Each of these three stereo buses then
feeds two tracks of a multitrack machine.
A mono L+ R feed is also derived from
each stereo bus. The A, B and C stereo
buses then may be combined onto the
stereo program bus to create the final
stereo mix. Stereo level controls adjust
the overall contribution of each bus to
the final mix. To compensate for the
mono phenomenon of center -channel
buildup, a separate set of mono trim controls is provided. These controls combine
the L+ R feeds from the A, B and C buses
into the composite mono output.
Computers
As you can see, the TV studio engineer
has a great deal to keep track of these
days. Fortunately, powerful assistance is
available in the form of audio production
computers. The first computer applications centered on automated mixing for
post -production. The early systems
recorded the engineer's fader adjustments and could later play them back
for modification. These systems were
primitive compared to the systems now
available.
Today's sophisticated dynamic mixing
automation allows mix data to be
manipulated and edited with uncanny
ease and speed. In addition to automated
level control, these systems provide
dynamic panning and even dynamic
equalization. These features are useful in
dialogue-matching and effects.
Some advanced computer -driven consoles allow complex transitions between
console presets in live situations. The
transition can be accomplished with a
single fader or switch providing instant
reset of the console's entire switching
Continued on page 52
with the all new LC75 "Z METER 2"
Capacitor Inductor Analyzer
Patented
$995
The "Z METER" is the only LC tester that enables you to test all
capacitors and coils dynamically plus, it's now faster, more
accurate, and checks Equivalent Series Resistance (ESR) plus
small wire high resistance coils.
Eliminate expensive part substitution and time-consuming shotgun-
-
ning with patented tests that give you results you can trust every time.
-
Test capacitor value, leakage, dielectric absorption, and ESR dynamically;
with up to 600 volts applied for guaranteed 100% reliable results it's
exclusive
it's triple patented.
Save time and money with the only 100% reliable, in- or out-of-circuit
inductor tester available. Dynamically test inductors for value, shorts, and
opens, automatically under "dynamic" circuit conditions.
Reduce costly parts inventory with patented tests you can trust. No
more need to stock a large inventory of caps and coils. The "Z METER"
eliminates time-consuming and expensive parts substituting with 100%
reliable LC analyzing.
Turn chaos into cash by quickly locating transmission line distance to
opens and shorts to within feet, in any transmission line or cable.
Test troublesome SCRs & TRIACs easily and automatically without
investing in an expensive second tester. The patented "Z METER 2" even
tests SCRs, TRIACs, and High -Voltage Diodes dynamically with up to 600
volts applied by adding the new SCR250 SCR and TRIAC Test Accessory
for only $148 or FREE OF CHARGE on Kick Off promotion.
To try the world's only Dynamic LC Tester for yourself, CALL TODAY,
WATS Free, 1-800-843-3338, for a FREE 15 day Self Demo.
-
Call Today Wats Free 1-800-843-3338
SNCORE
3200 Sencore Drive
Sioux Falls, SD 57107
605-339-0100 In SD Only
innovatively designed
with your time in mind.
Circle (18) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
49
Ili\ lib
One Tape for True Picture and Sound.
without fail, you need a tape you can turn to without
fear. 3M 480 "' Videotape. Designed to deliver exceedingly low video dropout levels-and extremely
high audio f delity. To give you a true pic_ure-and true sound.
To all those who have to get it on tt-e air
c
1986 3M Co.
www.americanradiohistory.com
TO THOSE WHO
ARE ON THE LINE
Er IT ON THE aR,
O E TAPE IS TRIE.
o
q
III
One Tape Stands True.
Getting you on the air without fail...that's what we've been doing since we invented videotape
30 years ago.
That's why we stand by you -with the largest support force in the field.
And we stand behind you -with some of the most advanced research in
the industry. All to keep our standing as number one in the world of the pro. nn A G N E T
nn E D
A
Scotch
PRO
1
1
NUMBER ONE IN THE WORLD OF THE
Circle (32) on Reply Card
www.americanradiohistory.com
3M
M-S: A special case
because the front of the S microphone
is positioned to the left. (The front lobe
of a bidirectional microphone is determined by the generation of a positive
electrical signal when a positive pres-
sure wave contacts the microphone
element.) A sound source on axis with
the M microphone is fed in phase to
both channels, appearing centered in
the stereo spread.
Directional cues to the right of center
are also achieved by summing the M
and S microphones. However, because
the right side of the S microphone is the
back lobe, sound entering this lobe will
be out of phase when mixed with the M
microphone. The S microphone must
have its phase reversed before summing with the M microphone to pro -
pattern overlay. Angles Al and A2 are
always equal and will vary depending on the
relative gain of the M vs. S microphones.
M -S
The M-S (mid-side) method of
microphone placement is a special
technique, developed by Lauridsen in
Germany, that is well suited to stereo
pickup. Similar to the coincident and
near-coincident X-Y techniques more
common to broadcasters, M-S stereo
uses two microphones in close proximity, or two independent microphone
elements within the same housing. This
Simple passive matrix to convert the mid
and side signals to left and right outputs.
technique provides phase coherence of
the summed L+R audio for good
mono compatibility.
The mid microphone can be omnidirectional, but typically is a cardioid
aimed directly at the primary sound
source. This microphone, when properly placed, will pick up all of the
if it were being
used monaurally. The omni pattern
tends to emphasize the ambient
(reverberant, or hall) sound, while the
cardioid tends to emphasize the
primary sound.
The M-S side microphone is always a
bidirectional (figure eight) microphone
with the pattern rotated 90°. The front
of the microphone faces toward the
left, and the back of the microphone
faces toward the right. In this way, one
of the pattern nulls lines up directly
with the cardioid M microphone axis.
This bidirectional pattern null is quite
deep-on the order of 25dB or more.
The S microphone picks up virtually
no central sound but, rather, sounds to
the left and to the right. Obviously, this
LEFT
duce a right channel output.
At that point, the final product is
essentially the same as an X- Y pair.
The real advantage to M-S is the ability
to alter the stereo spread (width) from
mono to exaggerated stereo simply by
adjusting the comparative gains of the
M and S microphones prior to the
matrix. This can be quite advantageous in video production because
you can adjust the audio width to
match the camera shot. In fact, the M
and S microphones can be recorded
directly onto separate tracks onlocation, then matrixed during postproduction to achieve the precise width
desired.
Finally, an M-S matrix can be
developed using four inputs on any
stereo console. Although more operationally cumbersome than a dedicated
matrix, it can be duplicated anywhere
with just a few commonly available accessories.
Simplified block diagram of an electronic
M-S matrix. Note the inclusion of a width
control. See the text for further details.
MID
u.
MID
MIC
LEFT OUT
primary sound, just as
combination of microphones will produce stereo sound with directional
cues, but how this technique is accomplished is what makes it unique.
Directional cues to the left of center
are achieved by summing the M and S
microphones together in phase,
Continued from page 49
network and fader levels.
Unquestionably, the studio computer
will play a steadily increasing role in improving the efficiency and creative flexibility of stereo TV production. A detailed investigation of the present hard-
ware and software capabilities and future
plans of the major console manufacturers
should be a part of your evaluation in
planning any MTS production facility.
A complex process
Unlike transmitter conversion, which
52
RIGHT
SIDE
SIDE
MIC v
RIGHT OUT
lj
WIDTH
CONTROL
An M -S matrix using four inputs on a typical stereo console. Two Y adapters and one phase reverse adapter are required to implement this technique.
MID
MIC
LEFT
OUT
SIDE
MIC
RIGHT
OUT
takes place in one shot, the conversion to
multichannel sound can take place over
a prolonged time period. The starting
point is to clean up your existing facility,
both acoustically and electronically. A
proof of performance should be run on
the entire audio chain and any weak
links should be replaced.
The next step involves equipment
upgrades and replacements. Start with
your audio monitors. You need a dependable reference point against which
to gauge all other changes. Take time
and experiment. You can learn a lot
Broadcast Engineering September 1986
www.americanradiohistory.com
before you spend any money. Effective
multichannel sound is a function of art as
well as science, and of technique as well
as technology.
Finally, beware of bargains. The
capital costs involved in a new console
and its associated support equipment are
considerable. The measurement of success is the return on your investment.
This return must be calculated in terms
of overall high quality, which your audience increasingly expects, and production efficiency, which your operation
I =r:-))ll)
demands.
Anything less than
a Neve is
just a lot of...
Stereo or mono modules
A choice of 4 standard consoles
Up to 8 auxiliary outputs
Bells and whistles may be all you
need for New Year's Eve... or a birthday
celebration. But is a desk full of bells and
whistles enough for the demanding art
and science of broadcast production? You
need the Neve difference.
At Neve, the first name in audio mixing control and distribution systems, we
offer you all the bells and whistles your
creativity demands...as well as the sonic
quality, reliability, and ease of operation
that sets Neve apart from the rest.
Neve's versatile 51 Series, for example,
gives you the full range of advanced
facilities you want, plus the virtually
unlimited versatility you require...to let
your creativity soar. With features that
include:
Custom configurations
16 -to -60 inputs
Rupert Neve Incorporated
Berkshire Industrial Park
Bethel, Connecticut 06801
Telex 969638
Facsimile (203) 792-7863
(203) 744-6230
'
Neve Electronics Intl Ltd.
Cambridge House, Melbourn, Royston
Hertfordshire SG8 6AU, England
ph (0763) 60776 fax (0763) 61886
telex 81381
Multitrack recording capability
4 -band Neve Formant Spectrum
Equalization
Hear the Neve quality difference for
yourself. Find out firsthand how Neve
advanced engineering gives you "a touch
of the future."
Circle the bingo
card for a literature
pack. Or call (203)
744-6230 for a
demonstration of
Neve sound at your
location.
Nothing sounds as good as a Neve...
because nothing else is.
7533 Sunset Blvd.
Hollywood, California 90046
(213) 874-8124
Facsimile (213) 874-1406
P.O. Box
40.
A Siemens Company
Nashville, Tennessee 37204
Telex 786569
(615) 385-2727
6
#
*
s
S. O
~
a
i
11
a
w
f
*
a
eplye
(-
www.americanradiohistory.com
,s
The real world
of stereoTV
By Dennis Ciapura
MINIMUM COST
Both business and technical
factors enter into the
decision to begin stereo
FULL CONVERSION
MTS
GO DECISION
TV
DOWNSTREAM INSERT
CONVERT STUDIOS
CONVERT STUDIOS
OR DOWNSTREAM
INSERT
No
REPLACE MASTER
CONTROL CONSOLE
REPLACE PRODUCTION
CONSOLE
CONVERT
DISTRIBUTION SYSTEM
1
CONVERT VTRs
STEREO SYNTH.
MONO SPLIT
\
STEREO SYNTH.
OR MONO SPLIT
..
MANUAL SWITCH
INSTALL STEREO
SYNTHESIZER
AUTO SWITCHING
AUTO OR MANUAL
STEREO SWITCH
CONVERT STL
INSTALL STEREO
AUDIO PROCESSING
INSTALL MTS
GENERATOR
MODIFY EXCITER
FOR WIDEBAND INPUT
OPTIMIZE/REPLACE
DIPLEXER OR
TRY AS IS
TRY AS IS
n
OPTIMIZE/REPLACE
TEST
PERFORMANCE
TEST MTS
PERFORMANCE
PERFORMANCE
UNSATISFACTORY
$100,000
54
Broadcast Engineering
broadcasting.
MODIFY OR REPLACE
DIPLEXER
matter how elegant the system, or
how thorough the planning, the real
world performance of any broadcast
technical enhancement is gauged by audience response.
This is especially true for stereo television. In many ways, the technical conversion process is the least taxing part of
the MTS (multichannel TV sound)
challenge. Understanding viewer reaction to the various technical aspects of
MTS is far more relevant from a business
perspective, and often more challenging.
Properly implemented and aggressively promoted, stereo sound could be the
most significant technical attraction
since color. However, broadcasters converting to the new technology face many
of the same hurdles that early color converts did. Television is a tough, competitive business and few companies
have unlimited resources for technical
improvements. Programming and promotional projects compete with MTS for
fiscal and human resources. And,
regardless of how quickly stereo receiver
penetration grows, it almost always
starts from zero.
Every reasonable business decision is
based upon a risk -vs. -opportunity
analysis. The risk side of the MTS equation contains a lot of certainties, including the installation cost and zero, or
near-zero, stereo penetration. On the
other hand, the opportunities are less
certain at this point, because there is so
little industry experience. If receiver
penetration grows rapidly, the stereo
pioneers will reap the benefits that accrue to the first in the game. These
benefits will be both direct and indirect.
As viewers purchase stereo televisions
Figure L Critical path analysis of MTS conversion process with minimum cost and fullconversion options.
COMMENCE MTS
OPERATIONS
>$350,000
September 1986
www.americanradiohistory.com
Ciapura, BE's consultant on radio technology, is president of Teknimax, a San Diego
-based telecommunications management consulting firm.
e
ONLY ONE CAMERA SHOOTS
THIS WELL IN 2 FOOTCANDLES.
IMAGINE NOW IT SHOOTS
IN BROAD DAYLIGHT.
The Panasonic' N-3
It's one of
a kind because it's the only camera
with three Newvicon' tubes. And
that means you get outstanding
NifeHaw4.7` NiteHawk"
picture quality under a wide variety
of lighting conditions.
When you're shooting at night
or in d mly lit locations, as in the
simula:ed example above, the N -3's
unique combiiation of three'/"
Newvicon tubes ets you make the
most of available light by providing
bright, natura v deo images.
In sunlight an: in the studio the
N-3 continues t_ shine with 600
lines horizontal -esolution. An
impressive S,N -atio. As well as
minimal lag, burn -in, comet tailing
and geometric cistortion. What's
more, the N-3 has all the professional fea -u -es you'd expect from
the broad line of Panasonic three tube cameras.
Still, with all the N-3 has going
for it, there's another bright spot.
Its price.
Audition :he NiteHawk and see
why from six -light to night light no
other camera can hold a candle to it.
Northeast: (201) 348-7620. Southeast: (404) 925-6835.
For more information, call your nearest Panason c regional cf ice
Midwest: (312) 981-4826. Southwest: (214) 257-7733_ Nest: (714) 895-7200. Northwest: (203) 251-5209.
Panasonic
Industrial Company
Circle (35. on Reply Card
www.americanradiohistory.com
and adapters, they are likely to tune in
some programs that they might not
otherwise view, to give the stereo a try.
A certain percentage will like the programs and stay with them for the long
term, even after the novelty of the stereo
wanes. That's a direct benefit. The improved station's image as a technical
leader in the market is an indirect benefit
of conversion.
The key to effectively optimizing the
risk-vs. -opportunity equation lies in
knowing how to get the best bang for the
buck on the risk side, while making the
most of the opportunities once the go
decision has been made. Over the past
few months BE has featured several articles dealing with transmission system
optimization, stereo audio proofs,
equivalent mode tests and programming
configuration for stereo television. This
article will provide an overview of the
technical factors from a business perspective with the objective of charting the
least costly and most effective path to
successful MTS deployment. This approach should be of value to broadcasters planning stereo conversion. The
overview also should be of interest to
broadcasters already converted to MTS
who may be confused by some of the
system's many anomalies or by the initial
audience response.
How much stereo?
The first tough point of decision is
reached before the conversion cost
estimate can even get under way. Should
the entire audio chain be converted, or
should network stereo programs be inserted downstream? Engineering purity
suggests that an immediate stereo conversion of the whole system is the right
way to go. Unfortunately, the financial
consequences of this would be enormous. As a matter of fact, the routing
and mixing revamping project would be
far more time-consuming and costly than
the transmission system conversion.
Adding the MTS generator, monitor,
stereo audio processing and STL
modification generally costs less than
$100,000. A new console and routing
system at the studio can quickly total an
additional $250,000. The downstream insertion option, therefore, has significant
expense advantages, and a reduced initial capital investment means less risk if
receiver penetration is slow to build.
One simple method of achieving a
downstream insertion is to switch to the
network audio feed at the input of the
stereo audio processing when the net is
feeding stereo. Although a manual
switch from mono to stereo is preferred,
the left channel is normally used for
mono programming. Therefore, the
switch may be triggered by the presence
of right -channel audio, which would occur only during a stereo feed. When
stereo is not available, the stereo audio
processor is fed from either the regular
mono signal split to both stereo inputs, or
from the output of a stereo synthesizer.
Some stereo synthesizers provide this
feature internally and need only to be installed in the output of the router to the
STL in order to accomplish automatic
stereo switching.
As with any new technology, practical
experience often dictates a somewhat
different approach than what seems obvious at the start. Gaining some operational experience with a simple system
to begin with, then converting the
studio(s) on a gradual basis when all of
the requirements and quirks are more
fully identified, can result in a much
more efficient and flexible system. As
few as three or four months can be invaluable for monitoring stereo programs
and getting a feel for what technical
parameters have the greatest practical
significance. If an immediate full conversion is preferred, discussions with
engineering staff members at other sta-
The SSL Stereo Video System
The Practical Standard For MTS Production
Before and beyond the transmitter, Multichannel Television
Sound is an art. In the studio and post -production suite, the
creative use of stereo can do as much or more than lighting,
lensing, colour and video effects to give depth, impact and
immediacy to the television picture. It quite literally adds an
entirely new dimension to the viewing experience.
In stereo, television is a whole new
ball game or newscast, or series,
-
or advert, or sitcom, or special.
Because stereo is both natural and
compelling, the programming
possibilities are as broad as the
imagination and skills of today's
sound designers. Technical limitations and the constraints of time
are the only obstacles. And
that's where SSL can help.
.9s:sMIR
of television audio production,
Only SSL has triple stereo mix
buses for stereo music, dialogue
and effects, plus rapid mix -minus
matrixing for Second Audio Program creation. Only SSL provides
compressor/limiters, parametric
equalizers, expanders and noise
gates on every channel plus
balance and image width controls
for all stereo sources. And only
SSL provides such time -saving operational features as patch free audio subgrouping and pushbutton signal processor
routing. For post -production efficiency, even the multitrack
electronics remotes are built right in. And that's just the
new line standard equipment!
-
tlegig
Our SL 6000 E Series Stereo Video
System handles complex MTS
production with unrivalled ease and
efficiency. Designed to simultaneously speed and enhance all aspects
the SL 6000 E Series makes
innovative stereo programming
practical on a daily basis.
-
Options include Total Recall' an SSL exclusive, completely
independent of the audio path, which allows any operator to
recreate the most intricate console setups for any programme
oawsw®
with rapid accuracy, week after week. Programmable dynamic
stereo equalisation and panning may also be added, along with
www.americanradiohistory.com
and with consultants who are experienced in MTS can be helpful in
avoiding costly errors.
Lions
The great synthesis debate
Stereo synthesis for television is one of
those areas in which things are not really
what they at first appear to be, resulting
in some unexpected viewer reaction. As
in the early days of FM stereo, when
stereo program material was less than
abundant, it is attractive to offer a synthesized stereo derived from a mono feed
so that the stereo pilot may be left on full
time. This maximizes the product differentiation that was probably an important factor in your decision to convert to
stereo. Unfortunately, like most wonderfully simple solutions, this approach is
not without its problems.
Astute viewers will soon realize that
the synthesized signal is not real stereo
and may conclude that stereo television
is deficient compared to the real stereo
they get from their VCRs and laserdiscs.
Then there are the mono and stereo
compatibility problems generated by the
synthesizers. There are two different
synthesis schemes in wide use today, and
each has its own peculiarities.
The band -splitting variety shunts
discrete frequency bands to the left and
right channels. This approach is based on
the theory that most sound covers a
relatively narrow frequency band and,
therefore, will flow to the channel optimized for its range. In theory, all of the
bands from the left and right add up to
the original mono signal in an L+R or
mono receiver. However, some broadcasters are finding that the process isn't
quite perfect and their mono sound on
the air simply doesn't sound like the
mono program feed. Thisecan be a problem because it means sacrificing the majority of viewers' mono sound to achieve
the stereo product differentiation. This is
a trade-off that many broadcasters are
loathe to make.
The other type of synthesizer
generates time -delay effects to produce a
stereolike sound. The inexpensive versions use bucket -brigade technology,
while the premium units employ digitaldelay lines. Either way, the result is the
generation of an L-R component
without affecting the L+R, so the mono
signal remains intact. However, this
system also has its problems.
An increasing number of viewers are
installing surround-sound decoders to
retrieve the sound effects that remain encoded on the stereo audio tracks of many
videocassette and laserdisc movies. Un-
fortunately, the L-R component
generated by the time -delay synthesizers
leaks into the surround channel, producing an
irritating echo effect. Also,
because the surround speakers in such a
system are usually inferior to the left and
right front speakers in such a system
(they normally only reproduce sound effects), the overall broadcast audio quality
is reduced.
Poor phasing integrity on stereo feeds
will cause similar effects. In either case,
the only solution is for the viewer to turn
off the surround sound when stereo
television is being received. This is
something the viewer does not have to
do when watching mono or stereo tapes
or discs.
The truth about companded L-R
Although the companded L-R that is a
part of the BTSC configuration is an excellent system and can yield greatly improved overall signal-to-noise ratios, it
also embodies several traps. First of all,
simply measuring the noise floor at the
stereo modulation monitor audio output
or at a receiver after the audio signal is
removed does not give a valid representation of audible noise performance.
High levels of incidental carrier phase
modulation (ICPM) will generate a buzz
multi -repeatable Events Control, Automatic
Dialogue Replacement, and centralised
command of up to five synchronised audio
and video machines. All of this is thoroughly
integrated with the SSL Studio Computerthe world's number one choice for mixing
automation.
Best of all, the SSL Stereo Video System is
not a hasty revamp of an old mono design. Nor is it an experimental project in search of a guinea pig. It is a practical,
reliable international standard for advanced television audio
production proven in well over half a million hours of
network and independent studio and mobile operation
in Great Britain, Japan, Germany, Scandanavia, Australia,
Canada and all across the United States.
-
-
Take advantage of our experience. Call or write today for a
free 40 page colour brochure describing the operation and
applications of the SL 6000 E Series Stereo Video System.
If your station or facility is contemplating an upgrade to full
MTS production capabilities, we'll be happy to arrange a
complete demonstration. And be sure to ask about our
training programmes.
Solid State Logic
Begbroke, Oxford, England OX5 1 RU (08675) 4353
200 West 57th Street . New York, New York 10019. (212) 315-1111
6255 Sunset Boulevard Los Angeles, California 90028. (213) 463-4444
www.americanradiohistory.com
behind the audio that will be quite audible when speech is present, but will virtually disappear when audio modulation
is removed. As a result, although conventional S/N tests will look quite good,
stereo -equipped viewers will get a buzz
burst with every syllable.
The better the viewer's audio system,
the more noticeable the problem. This is
because the extended low -frequency
response at the receiver exacerbates the
modulation noise problem. The real intent of the companding is to improve the
broadband noise performance of the
L-R channel and to minimize the
audibility of Nyquist slope ICPM in inter carrier detection receivers. Broadcasters
should not use companding as a cover-up
for transmitter ICPM.
Many stations will find it economically
attractive to begin MTS transmission
with their existing filterplexers and
diplexers. This will allow them to see
how they work before investing in a major RF plumbing project. That's fine in
terms of reducing the capital risk, but it
may be tough to keep the ICPM below
3% or 4%.
Fortunately, there is a way to minimize
the audible effect of the modulation
noise at the viewer's receiver. If the
15.734kHz pilot phase is shifted so that
Answering viewer
inquiries
As you might expect, early response
from viewers regarding stereo audio
includes some surprising comments
and unanticipated questions. The
following is a summary of the most
common ones and suggestions for the
station's responses:
*How can I receive the stereo sound
that you are advertising?
If the viewer's TV is less than two
years old, recommend checking with
the dealer or manufacturer to see if a
stereo adapter is available. Do not
recommend trying adapters not
specifically designed for the viewer's
receiver. Because of potential levelmatching problems with the com-
panded L-R signal, outboard
adapters are not as successful as were
the old FM stereo adapters. If a
dedicated adapter is not available and
the viewer is not interested in purchasing a new stereo television, recommend a stereo TV audio receiver. The
Radio Shack TV-100 drives line inputs
or external speakers directly, tunes all
VHF and UHF channels and seems to
be well received. As a matter of fact,
many TV stations are using them for
air monitors.
1 have a stereo VCR and yet I don't
get stereo from your station when I
feed the tuner output into my stereo
system.
Unfortunately, many VCRs, which
are equipped for stereo audio record
and playback, are not equipped with
MTS receivers. Viewers should be instructed to check their operator's
manual to see if MTS is mentioned. 1f
not, the VCR almost certainly does not
possess a stereo TV tuner.
There is a hum sometimes when
people talk or sing. I only get this on
your station. I have a new stereo
television that has outputs that drive
my stereo system with a speaker on
either side of the television.
At this point it is nice to know that
the station's ICPM is either low or
phase-shifted to null in a quadrature
detector. The viewer can then be told
that the receiver or cable system is the
problem. Viewers who use external
This new QuantAuralQA1OO Audio
Program Analyzer gives you the advantage
in competitive broadcasting
Simply put, the QA-100 quantifies what you
hear. Your station sound can now be electronically
monitored the way you hear it. Exactly. And, you
can monitor the competition tool
Real time analysis of any audio signal. From a
receiver, tape recorder, or processing equipment.
You see the measurements as you hear the sound.
Changes in processing or variations in system performance are immediately shown on the QA-100
panel meter or bargraph display-using program
material as the signal source.
The QA -100 hears like a program director and
talks like an engineer. With it you can monitor maximum peak level (relative peak modulation), overall
O TOMA C
processing effectiveness (average level), tightness of
sound and processing control (peak density), tonal
balance, consistency and preemphasis (four band
real time analyzer), stereo image width (L + R to
L - R ratio) and "punch" (special "aural intensity"
measurement)
Interested? To learn more about how the QA-100
will help your station compete, call Potomac
Instruments today.
INSTRUMENTS
932 PHILADELPHIA AVE. SILVER SPRING, MD 20910
(301) 589.2662
Circle (38) on Reply Card
58
Broadcast Engineering
September 1986
www.americanradiohistory.com
.
QuantAural is
a
registered trademark.
How to keep your
mixing board from
holding you back.
Today's technological revolution is a
battle fought on two fronts: quality and
cost. Recent advances in recording equipment let you do more than you ever
could before And for less money. But
what about your mixing console? Can it
keep pace with recent giant steps such as
the significant advances in the quality
of analog and digital recording
equipment? Without sacrificing
your budget?
If you're mixing on a RAMSA
WR-T800 series console, the
answer is yes. RAMSAs 8 -buss
consoles are a smart choice for
8 or 16 -track recording. They
offer the quality you need to
II,ICT
bring your recording chain up
to today's demanding specs.
-
F:=N1 M
51 -ND
X
I
s
Panasonic
Industrial Company
SI IFCI
I
F
PCC 1.1
Program
Mix Control
RAMSA's T-Series
consoles save you
time, too. Each input channel simultaneously accepts
Mic, Line and Tape signals. A timesaving feature, the Program Mix
RAMSA WR T820
©
.4BV
mu
PHASE
MIS:
IN,
113
TAPE
INPUT
MIC
I INC
TRIM
Pushbutton
Input
Selection
CfvLl
SI IVO l'AN
SI NI,
control and stereo Solo switches
let you choose the signal
source you want without re patching. So you get from
basic tracks to final mix in
record time.
Because with the RAMSA
T-Series, you get a mixing board
that does much more for less
without holding anything back.
1186 Panasonic
Cit cle (37) on Reply Card
www.americanradiohistory.com
speakers from their stereo systems will
be the ones to first notice the buzz
because of the extended low-frequency
response, especially if the loudness
contour is turned on.
*When a talk show is on in stereo
the announcer's voice tone seems to
change periodically.
Some
stereo
synthesizers
switch
automatically from stereo pass through to synthesize when they sense
equal left and right, which would be
the case with a mono signal. Unfortunately, an announcer speaking alone
and mixed to center produces the same
signal. The synthesizer thinks it's a
mono program and switches on. The
solution is to disable the mono -sensing
feature in the synthesizer so that it
senses mono only when a left -only
signal is present. It is not often that a
left-only mix shows up during a
stereocast, but it can happen. An interview is one case in which this can occur. Ideally, the mono -to-stereo switch
should be done manually.
*After I hooked up my stereo to my
stereo TV receiver the picture got
worse.
Ask if the viewer used a signal splitter to obtain an antenna signal for the
stereo receiver. The additional loss
may be just enough to drop the television below its noise -free threshold. This
can be a problem if several sets in the
house are driven by the same antenna
or cable. Also suggest that the viewer
check all antenna leads. In just hooking up an external speaker, an unwary
viewer can sometimes pull the shield
away from an F connector.
the buzz is nulled out in a quadrature
detector, the effects of the high ICPM on
the viewer's audio will be greatly reduced. The pilot phase adjustment on the
stereo generator can be used for this. An
adjustable delay in the video input at the
exciter should have the same result.
Another trap lies in the critical nature
of the level -matching requirements in
the BTSC mode. Because the L-R channel is companded, stereo television is not
like stereo FM. Stereo TV receiver
decoders are calibrated to precisely track
the 25kHz L+R and 50kHz L-R deviation references. The station must meet
these standards precisely or stereo
separation will rapidly deteriorate. This
is why it has been suggested that finetuning of the transmission system should
be done in the equivalent mode (uncompanded L-R for testing). (See
"Understanding MTS Equivalent Mode,"
page 52 in the September 1985 issue of
Broadcast Engineering.) Otherwise,
the effects of transmission system nonlinearities are hard to detect in the
presence of compander tracking and
matching induced separation losses.
The best approach is to check out the
transmission system first by making
separation measurements in the
60
Broadcast Engineering
equivalent mode, then follow up with
separation measurements in the BTSC
mode to check compander tracking
against the standard in the demodulator.
The companded tests should be made
at several levels to assure acceptable
tracking. Equivalent mode separation
figures of about 40dB and BTSC figures
of about 30dB should be easily attainable. Level and frequency response
errors inside a companded loop are
multiplied by the amount of the
companding ratio, which is 2:1 at low
frequencies and 3:1 at high frequencies.
This means that the stereo performance
of MTS is two to three times more sensitive to differential (L+R vs. L-R) gain
errors as stereo FM.
Fortunately, the stereo generator at
the station is not likely to require much
maintenance. However, it is essential
that good BTSC separation figures be
verified when the conversion is first
made, because it is inevitable that there
will be viewer complaints about stereo
reception. It is imperative that the station
knows for sure that its stereo signal is
properly operating. This is especially
true where there are intervening cable
systems. The trap lies in taking the companding for granted. If you do, you'll
forever wonder if the viewer problems
with stereo are somehow related to
diplexer bandwidth.
Promotional considerations
After the stereocast commitment has
been made, it's important for the station
to take the lead in helping receiver
penetration grow as rapidly as possible.
This may be critical if there is to be a
reasonable return on the conversion investment through increased ratings. The
public can be induced to buy stereo TV
equipment only if they know about the
stereo and good stereo programs are
available to enjoy. Although "Miami
Vice" in stereo on NBC may be a super
draw, local production opportunities
should not be dismissed.
Los Angeles independent, KTLA-TV,
broadcasts the Rose Bowl Parade in
stereo, and what a viewing experience
that is! Chief engineer Ira Goldstone is an
MTS pioneer, having made the conversion in 1984. KTLA also produces
baseball and basketball games in stereo
to supplement syndicated features, such
as "Fame," that are available in stereo.
Many films also are available in stereo,
and despite some of the concerns expressed at last year's SMPTE/USC stereo
conference regarding the suitability of
stereo film mixes for television, the
author has auditioned dozens of laserdisc
stereo releases and found them all to be
acceptable, and most of them great.
These same audio mixes are available for
TV broadcast.
On-air promotion of the stereo
September 1986
www.americanradiohistory.com
capability should include a brief message
about how to receive the stereo. It's best
to recommend only a stereo television or
stereo audio receiver in the promo.
Recommending stereo VCRs or adapters
could come back to haunt your station.
Getting stereo program notations in
local newspaper TV guides should not be
too difficult. However, as yet, the national TV listings have been slow to respond. This probably means that the
country's stereo TV broadcasters have
not been assertive enough in exploiting
the opportunity to differentiate their air
product.
MTS makes sense
The MTS environment today is, in
many ways, reminiscent of the early
days of FM stereo. There are few stereo
receivers, most programming is still
mono and the audience, for the most
part, doesn't understand or care about
the technology. There's just one big difference. You are talking to a different
consumer these days, one who will buy,
watch, listen, smell and feel anything
that is promoted as being new and good
to have. Stereo already has become a
part of everything from VCRs to
miniature radios and cassette players for
joggers. Stereo television is here to stay,
and it makes good business sense to get
in early and learn the craft of broadcasting it.
The best part about stereo television is
that it's really easy and inexpensive to
convert. Although some diplexers may
not be ideal for MTS, most will work.
Many older exciters can be converted
easily to accept a wideband audio input
with a simple card or module change.
And, downstream audio insertion allows
quick and inexpensive participation.
Network affiliates can look forward to
ever-increasing releases of satellite delivered stereo programming. In addition, almost every movie produced in the
past few years has been recorded in
Dolby stereo. All this means that the
stereo programming is available and that
even more programs will become
available in the future.
The successful stations are going to be
those who take advantage of the MTS
system now. They stand to reap the
benefits (and profits) of early conversion.
Over the past 12 months, the number of
stations broadcasting in MTS has increased tenfold. These stations are
broadcasting not only network stereo
programming, but also locally originated
stereo programming. In most cases, the
stations convert to stereo as a means to
attract a larger local audience.
It appears as though stereo broadcasting will soon become a way of life for
TV stations. If your station has not yet
converted, it is time to give the matter
careful thought.
I =r:.)))ll
THE PERFORMER
The DVE System 10 from NEC is one of
the hottest selling digital video effects systems
on the market today. For good reason: it performs. To find out for yourself, just spend a little
time behind the controls. Get a feel for 3-D roration, infinite perspective, cube making, tearing, A/B switching, key masking an ease of use that will make
you feel like an expert in no time.
The word is that the DVE System 10 is
quickly becoming the choice for TV stations,
production, and post-production facilities
throughout the country.
So take yourself on an adventure in creativity with the system backed
up by one of the biggest names
in the industry. The DVE
System 10 from NEC.
NEC
IMAGINE WHAT WE'LL DO FOR YOU
DVE is a registered trademark of NEC Corporation.
1255 Michael Drive, Wood Dale, IL 60191
Toll free 1-800-323-6656 In Illinois phone 312-860-7600
CCCOMPUTERS AND COMMUNICATIONS
NEC America, Inc., Broadcast Equipment Division
Circle (39) on Reply Card
www.americanradiohistory.com
Linear keying
in video production
By Tom Goldberg
By using linear keying to soften, highlight and blend images, you
can create design effects that give you the edge in video production.
precise control of key levels and object
edge definitions-were impossible to
achieve. These fall into the category of
effects called linear keying.
The value of keying
Few TV productions rely strictly upon
simple title keying. In most cases, a full capability keyer provides the numerous
key applications used in the video. Matting, seamless inserts and special effects
with glowing and soft edges are requirements of many producers and commercial clients.
Achieving such effects hinges on advancements in keying technology and
the development of high -gain, finediscrimination and low-gain, naturaledged keys. Typically part of the production switcher, effects keying should play
a role in a new switcher.
Key issues
Linear keying describes the new
generation of switcher effects. However,
a number of questions have been raised
in regard to the technique. They include:
Exactly what is linear keying and
what are its advantages?
How important are high -gain keys
where linearity is not critical?
Are linear low -gain keys possible
when control originates from an external
source?
How does the degree of linearity appear in the final key? and
How important are exact minimum
gains in different keying applications?
Answers to these questions and an
understanding of basic keying concepts
explain how different key effects are accomplished.
Reviewing techniques
What is thought of as keying today
bears little resemblance to the original
concept of keying. When commercial
television first began, keying usually involved a non-additive mix between the
background and key video signals. The
result was more of a superimposition
than a key with the brighter of the two
images being dominant. The technique
worked fine if the background was no
brighter than the key. Otherwise, portions of the keyed information were lost
in the surrounding image.
In searching for a better method,
designers sought to emulate the film
technique of creating a matte, that is,
cutting a hole in the background and
substituting other video where the
background had been cut away. The first
keyers accomplished this goal electronically. Although early keyers made
titling, bordering and other simple matting tasks possible, the film-quality appearance was not achieved. Edges often
displayed peculiarities of high-speed
switching between the video sources.
A gain control, usually labeled edge or
soft, brought an initial solution for better
T
100IRE
1_
LINEAR,
1:1
GAIN
T
1_
100IRE
10 -step key signal
used with three different gain values of linear
and non-linear keyers.
Figure 1. The result of a
LINEAR, 2:1 GAIN
The
repertoire of special effects that
are made possible by the keying facilities
in modern video production switchers is
increasingly diverse and sophisticated. It
wasn't that long ago that soft-edged keys
and glows around images-the results of
Goldberg is product manager for switcher products,
Ampex Corporation, Wheatridge, CO.
62
Broadcast Engineering
T
KEY SIGNAL
September 1986
www.americanradiohistory.com
T
1001RE
1_
NONLINEAR GAIN
APPROXIMATELY 1.4:1
"Our purpose is to
keep you on the air.
Our extensive inventory of broadcast tubes, RF
transistors and related components ensures delivery
of the product to you on time -even if have to run
the package to the airport myself. Last year our
company made over 7500 overnight deliveries, so
we take emergencies seriously!"
l
Rector Munoz,
Distribution Services
Manager
$30 Million Inventory 98% Same Day Shipment
Technical knowledge to
help you save time and
money by choosing the
right component.
PRODUCTS: Cathode Ray Tubes Diodes Klystrons Monitor Tubes
Plumbicon Tubes Receiving Tubes RF Ceramic Capacitors RF Transistors
Saticons Solid State Replacements Transmitter/Power Tubes Tube
Sockets Accessories TV Linear Devices Vacuum Capacitors Vidicons
Vistacons
MANUFACTURERS: Acrian Amperex Cetron EEV Eimac GE Hitachi
ITT Jennings Machlett National Philips RCA Raytheon Thomson
CSF Varian Westinghouse
800-323-1770
Circle (40) on Reply Card
Richardson
Electronics, Ltd.
Broadcast Division Calvert Electronics, Inc
Convenient Sales Offices: Franklin Park,
IL Woodland Hills, CA Belmont, CA Dallas, TX
Norwell, MA Rockville Centre, NY East Rutherford, NJ Winter Park, FL Brampton, Ontario,
Canada Lincoln, England Gennevilliers, France
www.americanradiohistory.com
keying. With gain control, keyers were
better able to achieve the level and clarity of film matting. Continued research in
keying technology has expanded the
range and precision of the full-capability
linear keyer.
More than a name
Linear key systems are available in
most modern, high -quality switchers.
When the unit includes gain control
through a softness or key edge adjustment, the keyer could be considered
linear. In most traditional keys, as with
many character generators, whether or
not the key is linear is a moot point. Rise
times of the video are fast and the levels
are either black or white. The result is a
key that is either fully in or fully out at
any instant in time, regardless of where
the gain or clip level is set.
Linear keying becomes more important, however, when the key signal rise
times have significant slope or when they
contain differing video levels and when
the desired result contains areas of
mixed key and background video. Consider, for example, a fuzzy appearance
or glow around an object or title. The
source image is from a monochrome
camera. When the camera is defocused,
images no longer have sharp rise times
because, in the blurred area, the image
creating the key may vary from black
through gray to white.
A truly linear keyer enables the creation of a mix between background and
insert video within this blurred region.
The clip level determines the point on
the control signal slope where the
nominal mix occurs. The gain control
determines the width of the resulting
mixing region. From a different point of
view, the gain control adjusts how much
of a change in key video is necessary to
mix the key from fully in to fully out.
With high -gain keys, a slight change
causes the key either to replace the
background entirely or to not be visible
at all. As gain is reduced, a greater
change in key video is required to cause
a complete swing in the effect video. Between the extremes, insert and background video signals mix in proportion
to intermediate values of key video.
Low -gain keying first appeared in the
RGB chroma -key. Until recently, most
chroma-key effects were obvious, showing peculiar sizzling or sparkling edges.
By lowering the gain during keying, such
undesirable edge effect can be minimized. Even a sharply focused camera
image has significant rise times around
chroma -key subjects. Therefore, slight
gain reduction allows the keyer to mix in
the subject during those rise times.
The need for high gain
Reduced gain is not solely responsible
for the clarity of high-quality keying or
A friend for life.
It's time you got to know Orban's 422A (Mono)/
424A (Dual-Channel/Stereo) Gated Compressor/
Limiter/De-Esser-known in reputable broadcast
circles as the "Studio Optimod". Users of the
422A/424A tell us that what impresses them most
is the unit's astonishingly natural sound-in fact,
"non-sound"-even at high compression ratios and
with substantial gain reduction, where most other
units pump and breathe.
Whether you use it as a hard or soft peak limiter,
a gentle "soft -knee" compressor, a full function de esser, or all simultaneously, the versatile 422A/424A
gives you the controls you need to get your sound
Linear keying hinges on the real differences between the key signal and
the key insert. The key signal controls
when the key is in, out or in between. It
is often referred to as the hole cutter.
The key insert or fill signal is video
that appears in the hole in the output.
In self-filled luminance keys, the key
and the insert are from the same
source. Examples of effective self-filled
keys are simple character generators
or monochrome cameras.
Greater sophistication involves key
signals and inserts from different
sources. Most high -quality character
generators and digital effects devices
provide key outputs that are separate
from the key video.
The RGB chroma -key was the first
commonly used process in which the
key was not the same as the insert
video. Separate R, G and B video
signals, fed to the switcher independent
from the camera composite signal, are
processed independently to create a
shape based on some desired chroma key hue. The shape cuts the hole for
the inserted composite camera video.
Another example of different key
and insert signals is the matte -filled
key. In this case, the insert is a full field
of solid matte color that appears only
where determined by the key signal.
just right-quickly and surely. Best of all, the 422A/
424A's wide control range means that the same unit
can create either natural gain -riding or special effects-you don't have to buy two boxes to get these
capabilities.
One economical package is all you need to handle
your basic production level control chores, DJ mic
enhancement, or STL/telco protection. The 422A/
424A does it elegantly with a timeless design that
will solve your gain -control problems now, and for
years to come.
Get to know Orban's 422A/424A "Studio Optimod".
It'll be a friend for life.
0t aA
Circle (41) on Reply Card
64
Hole cutters
and fillers
Broadcast Engineering September 1986
www.americanradiohistory.com
Orban Associates Inc.
645 Bryant St., San Francisco, CA 94107
(415) 957-1067 Telex: 17-1480
PAY LESS ATTENTION TO
YOUR VIDEO CART MACHINE
Now Available in
BetaCam Format
Great idea! Now you can do just that with the TCS2000.
The Cart Machine automatically manages, records and plays -to-air
all forms of spots and programs, giving you much more uninterrupted
time away from programming concerns.
The Cart Machine holds up to 280 carts on-line. Tracks 65,000 carts
in the database. With its 1,000 event look ahead feature, you receive a
printed list of needed carts and your saturation spot carts never have to
leave the machine.
The Cart Machine's comprehensive software system interacts with
your traffic system to download your logs and automatically preplans the
spot play lists days in advance.
Now other station operations get your undivided attention-with
The Cart Machine.
Ode
l«
We put smarts in The Cart Machine.
Odetics, Inc. 1515 S. Manchester Ave., Anaheim, CA 92802-2907.
Call toll free 1-830-243-2001. In California call 800-238-4422 or 714-774-5000.
Circle (42) on Reply Card
www.americanradiohistory.com
compositing. If the key signal rises more
slowly than the response time of the
keyer circuit, reducing gain will soften
the edge of the key and frequently yield
a more natural appearance. However,
other issues are also involved.
Low gain significantly eliminates a
pasted -on look, but when fine differentia-
tions
between
Keying on components
Video production switcher specification sheets often indicate that chromakey is available. Some models include
a chroma-keyer as standard equipment, while others offer options of encoded and/or RGB systems.
Of the two, the RGB-type keyer
should be the simpler because specific
levels of red, green and blue signals
form the keying pattern. Encoded
chroma-keyers must first decode the
signal to RGB with the risk of noise
entering the decoding process.
Chroma -keying with component
signals introduces another challenge.
video levels are
necessary, higher -gain systems should be
used. For example, consider a logo that
is to be keyed over a picture of the
automobile dealership's building. The
logo contains highlights, reflections and
near blacks. Because of the logo variations, any background selected may include areas approximating levels created
by features of the logo. You run the risk
of punching holes in the logo image.
Higher key gains used on the logo improve the chance of discriminating from
among the subtle levels of luminance.
The standard video black level (setup)
is 7.5IRE units. High gain in keying is important if superblack (between OIRE and
7.5iRE) is involved. A common production problem arises when an image is
transferred to videotape for later keying
into a new background. One method
would place the image over a solid color
on tape, followed by a composite
chroma -key. That method seldom looks
as good as a luminance key, however.
This can be further complicated by the
fact that the colors in the image may
Because of differences in the signals,
RGB keyers cannot directly handle
Y/I/Q,
Y/U/V or Y/R -Y/B -Y
signals without some alteration of the
key matrix circuits.
Solutions to this dilemma include en-
make it impossible to find a unique solid
background color.
Another solution is to place the image
over superblack for the recording.
Recombining the image uses
a
luminance key, setting the clip level between the true black and superblack.
This may require an exceptional amount
of gain, however. The videotape playback contains roughly l IRE unit of noise
at both the true 7.5iRE and OiRE levels,
coding
to composite video, then
decoding to RGB. High -quality encoders and decoders make this a viable
alternative,
but
whenever
active
devices process signals, the possibility
of artifacts and noises exists.
Transcoding or intermatrix products
allow any component format signal to
be translated to any other format.
Without introducing reference subcarrier to the rematrixing process, the
resulting signals maintain the component video advantages.
A third possibility places format
compensation in the keyer as semiintelligent matrices. From switcher
panel controls, adjustments to
multiplier circuits in the level -sensing
key matrix can be made through software, providing a flexible system that
adapts easily to the signals in use.
leaving a 5IRE window in which to differentiate between the subject and the
background. In such a situation, the highgain keyer overcomes the limitation of
keyers that can differentiate a 4IRE to
5IRE level change at best.
External keys
So far, this article has discussed simple
keying, or the self key, in which the key
Continued on page 70
AUTOMATED
BROADCASTING
SYSTEMS
Four Models
SOL -6800 / MICRO
For VTR with 4 -input AV switcher
From
1
$2,500
SOL -6800 / MINI
(Fully programmable)
For 4 VTRs with 6 -input AV switcher
From
$9,000
SOL -6800 / U.I.S.
(Upgradable intelligent system)
DPS-170 Time Base Corrector
New technology yields a price/performance
breakthrough in a single, space -saving rack
unit. The DPS-170 time -base corrects
monochrome and heterodyne inputs for editing,
assembly and match framing. Direct -color is
achieved with 3.58 MHz feedback to
tape player.
The DPS-170 gives you a wide dynamic
tracking range of -1 to +3 with clear viewing at
up to ±30X normal tape speed. You get tape
source flexibility, with a 16 -line buffered
120 Middlefield Road, Scarborough. Ontario
Canada MIS 4M6 (416) 299-6888 Telex 065-25344
correction window and RF/TTL selectable drop
out compensator input.
- High performance/low cost
- Heterodyne or Direct Colour
- Dynamic Tracking® capability
- Digital Dropout Compensator
- Matched Frame Editing
.Trade mark of Sony Corp
Scientific
Atlanta
Digital Video Systems Division
Circle (43) on Reply Card
66
Broadcast Engineering
September 1986
www.americanradiohistory.com
For 8 VTRs with 12 -input AV switcher
From
$12,000
SOL -6800
(Fully programmable expandable)
For 8 VTRs with 12 -input AV switcher
From
A
$17,000
COMPANY DEDICATED TO AUTOMATION
SaLuTEL
H.A. Solutec Ltd.
4360 d'Iberville, Montreal
Quebec Canada H2H 2L8
Tel: (514) 522-8960 Telex: 055-62139
Circle (44) on Reply Card
IMPORTANT NEWS
Miller Fluid Heads are pleased to announce, for the first time, their entire
range of professional camera support products are now available in the
United States, direct from the manufacturer.
12 MODELS OF ENG/EFP FLUID HEADS,11 MODELS OF ENG/EFP TRIPODS,
DOLLYS, SPECIAL APPLICATION MOUNTS, ETC.
Mil liv 4
y
aim
Apro
f
es
.
1%'
44K
+r_
Ill
41110
elb
w
MILLER
co.TY
pRex
MILLER FLUID HEADS [USA) Inc.
2819 W OLIVE AVE, BURBANK CA 91505, Tel: [818] 8416262 Tlx: 283223
SUPPORTING AMERICAN FILM AND TELEVISION SINCE 1957
Circle (45) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
67
LINK YOUR NEWS VEHICLE AND STUDIO INSTANTLY VIA SATELLITE,
Wherever your satellite news gathering
truck goes to get the news, you have to communicate with your crew. And get the story on
the air. COMSAT General's SkyBridge is the
quickest way to do both.
SkyBridge is the complete, end -to-end voice
and video communications service designed
specifically for broadcasters. It lets you communicate instantly between your studio and
remote locations as easily as picking up a
phone, using Demand Assigned Multiple Access
(DAMA) direct dial telephone connections (the
industry's least expensive and most flexible).
And your network can be managed from our
central operations facility for timely scheduling
and cost -saving transmission.
A PERFECT, YET EXPANDABLE FIT. SkyBridge can
do whatever you want to do, using full or half -
COMSAT is a registered trademark and service mark of the Communications Satellite Corporation.
www.americanradiohistory.com
transponder Ku -band satellite capacity. Change
your voice communications (including IFB) to
meet your needs on a day-to-day basis. Create
instant networks using multiple trucks as temporary uplinks, and control them from one
source. It's your network. We'll help you
manage it. Your news
crews go anywhere to
get the story first. With
SkyBridge, nothing gets
in their way.
For complete details on SkyBridge and our
other video transmission services (including
end -to -end broadcast networks, backhaul net works and transponder leasing), call Art Hill
at (202) 863-6909.
61' COMSAT GENERAL CORPORATION
i
950 L'Enfant Plaza S.W.
Circle
www.americanradiohistory.com
SM
Washington, D.C. 20024
(46) on Reply Card
Switching components
According to some engineers, the
most difficult design aspect of a video
production switcher is correct timing.
The only aspect that might be more difficult is the human interface, that is,
the control panel itself.
When a video production switcher is
installed, a special effort is needed to
allow for and correct signal timing
from all sources through video cable
lengths, adjustable delay lines or
through a system of sync generators
that provide for delay compensation.
(For more details, see the articles "Sync
Processing and Distribution" and
"Understanding SC/H Phase" in the July 1986 issue of BE.)
1f you assume all signals are in time
at the switcher inputs, then they must
remain in time, even though one or
more have taken paths through mixeffects amplifiers, multiple re-entries
Continued from page 66
signal and the insert video are the same
source. Isolated or external keys present
a different challenge because separate
hole cutters and insert video are provided. Although linear keyers perform the
self key well, not all are capable of doing
a low -gain key based upon external key
signals. In order to take advantage of to-
Talk Shows
Aren't Tough
Anymore!
adjustable variable delays, the engineer can compensate for differences
between the components more easily.
Some in the broadcast industry have
indicated a disappointment in the slow
movement toward component production. One of the reasons results from
the number of changes made since the
and keyers. An important specification
for system design, when considering a
new switcher, is the electrical path
length, usually given in nanoseconds
or in degrees of subcarrier.
Switchers designed to use analog
components present additional difficulty. Three paths for each input must remain in time along the entire length of
the switcher. Any instability among the
three component channels causes a
lack of sharpness and color purity in
the resulting images.
The stability of electronic devices in
modern systems makes possible
switcher designs incorporating fixed or
variable delays along the length of the
electrical path. Fixed-delay designs require the engineer to ensure that all
three component signals from each
source are in time at their entry point
into the switcher. With the alternative,
first component camera/recorder
products were introduced. The lack of
component products covering segments of the production process, particularly switchers, video monitors and
monitoring systems, has helped to slow
the conversion to components. The
problems will lessen as complete component systems are introduced.
Designs are expensive without a
ready base of customers. On the other
hand, without available products,
equipment users tend to shy away from
concepts that lack a visible manufacturer base. As manufacturers and
users become better acquainted with
analog or digital component operation, component use will increase.
repertoire of production tools,
graphic art paint systems, digital effects
units and anti-aliased character generators, the keyer must work with a signal
that is separate from the insert video.
In the case of a digital effects unit,
under normal circumstances the external
key shape comes into the switcher from
the effects system to cut a hole precisely
the size and shape of the reduced raster
coming from that unit's composite video
output. Keyer gain is not necessarily
critical, because the rise times are fast.
However, if an effects system keysoftness feature is used, the hole -cutting
signal will have sloped edges.
Suppose the desired effect is for the
keyer to mix between the background
day's
2
Cleanest, Fastest
Catch-up Ever...
BD980 Comes Fully
Loaded.
3
Stereo Audio So Clean..
Automatically builds up delay
quickly and inaudibly. Uses
exclusive Eventide patented
technology for catch-up quality
light-years ahead of earlier
designs.
Stereo operation, 20kHz.
bandwidth and 10 seconds of
delay are standard. And
BD980 is priced to be a
great value.
You'll want to keep the BD980
in -line at all times. BD980 features 16 bit linear PCM design
and 50kHz digital sampling
rate.
a
BB
ss
Eventide
All of BD980's automatic
modes can be set to give you
4, 6, 8 or 10 seconds of on -air
stereo delay.
Wert
Takes The
Hassles Out Of
Talk Show Production
...Sounds Better, Too
It's A Stereo Time
Compressor, Too.
Get OUT Of Delay
Instantly shortens (or lengthens) audio spots up to ten
seconds. Better stereo/mono
phase compatibility than
megabuck single purpose time
compressors. Works with ANY
cart or tape machine
variable speed NOT required.
-
Es
...
As A Production Tool
BD980's Manual mode lets
you set delay in one millisecond steps, from zero to 10
seconds. Ideal for vocal doubling, echo, and other effects.
Eventide Inc.
,
One Alsan Way
Broadcast Engineering
7
Switch To A Helicopter
Traffic Report...
Or other "live cued" event,
with no timing or monitoring
hassles. Just push the WAIT &
EXIT button. The Eventide
BD980 makes the "impossible" switch easy!
9
Large Alphanumeric
Display.
Shows amount of delay,
"safe" reading and operating
mode at a glance. BD980
operating functions are fully
remoteable and plug -compatible with our BD955.
Little Ferry, New Jersey 07643
Circle (47) on Reply Card
70
...
Just push the RAMP TO
ZERO button and go on with
the show. It's that simple.
Delay inaudibly"catchesdown" to zero. antic switching or monitoring hassles?
Forget 'em!
-
Available Now! See how
easy talk shows can be
Call your Eventide dealer to
arrange for a demo.
Or call Eventide direct at
1 (800) 446-7878.
Eventide
the next step
6
When It's Time To
5
New Eventide BD980
Broadcast Delay
or
10 Seconds
Of Stereo Delay.
4, 6, 8,
September 1986
www.americanradiohistory.com
J
(201) 641-1200
The Abekas A53 -D
Digital Special Effects System
The innovative tradition of Abekas
continues with the A53-D-the
most cost-effective, high -quality
three-dimensional effects system
available today.
In single or dual channel configuration, the A53-D gives you a full
array of three-dimensional features.
These include: perspective and 3D
rotation, variable rotation axes and
3D locate, field/frame freeze and
full manipulation of frozen pictures,
variable border and background,
crop and aspect change, A/B switch-
ing and GPI control, and smooth
linear motion and trajectory with
variable tension.
The A53 -D makes good sense for
both live broadcast and post-production applications. For broadcasting,
the A53-D offers a simple -to -use
control panel with fast access to 24
on-line effects. For post -production,
the system's extensive programming
features and precise control let you
create intricate effects limited only
by your imagination.
You can digitally interface the
A53-D to the highly acclaimed
Abekas A62 digital disk recorder.
This unique duo gives you the ability
to composite unlimited layers of
manipulated video without generation loss.
Let the A53 -D add a whole new
dimension to your bottom line,
with unmatched price and performance. For details, contact: Abekas
Video Systems, Inc., 353A Vintage
Park Drive, Foster City, CA 94404
(415) 571-1711.
Abekas
Video Systems, Inc
Now Anything is Possible
Circle (48) on Reply Card
www.americanradiohistory.com
---LOWGAIN WINDOW
CLIP LEVEL
KEY SIGNAL
i
BACKGROUND
KEY
TYPICAL HIGH -GAIN KEY
UNITY GAIN
WINDOW
KEY SIGNAL
BACKGROUND
KEY
UNITY GAIN KEY
and effects video during the sloping
region of the key signal. The effect is
possible only if the keyer can apply
variable gain to the isolated hole -cutting
signal. To circumvent this necessity requires patching of video and tying up additional capabilities of the switcher.
A favorite effect in today's production
market involves flying a key signal and
its associated video around the screen. If
the key signal has any softness, then the
flying image can be combined with soft
edges blending into the background. To
accomplish this, a hole-cutting signal applied to the digital key channel of the
digital effects unit produces an output for
rekeying into an image. With external
linear keying capability, the rise times of
the key signal maintained in the effects
equipment make the flown image look
more natural.
Another application requiring linear
keying from an external key source in -
.
1'
1
I
I
1
BACKGROUND
KEY
TYPICAL LOW -GAIN KEY
Figure 2. A view of the key input and
background signals shows their interaction in
different keyers. In the low-gain key, the window moves and changes size with clip setting.
volves an independent key hole from the
graphic art paint system. The artist
creates a soft-edged shape with the
graphic airbrush to produce a highlighting glow around an advertised product. The shape signal is then fed into an
isolated key input of a linear keyer.
Degrees of linearity
As long as keyers have high gain for
level discrimination and low gain for any
type of key, most production requirements can be met. Because image
quality is the goal, however, other factors should also be considered.
For a keyer labeled as linear, the question arises as to how linear, and how low
a gain is available. Accurate linearity is
important when the production calls for
precise control over the smoothness of
transitions between insert and background videos. Often the difference between true and approximate linearity is
visible only through close scrutiny, but
production clients have a way of seeing
the smallest discrepancy.
The degree of linearity determines if a
certain percentage of change in key
video yields the same relative percent -
age variation in the key and background
mix at high- and low -luminance levels.
To measure this, you can key a
monochrome stairstep over black with
low gain and a white matte fill. Then,
determine how much variation exists in
the number of IRE units between each
step with a given clip and gain setting.
The measurement of keyer linearity
requires that the key be white -filled over
black (or vice versa), so the key signal
determines how much white is mixed
with the black. If the key were self -filled,
each step of key signal would control
how much of that same luminance mixed
with the background. This would yield
the product of the video times itself, a
squared relationship and a resulting key
that is far from linear.
Minimum gain factors
Just how low is minimum gain? For
most practical low -keying work, a gain of
two will do. For a 10IRE change in key
signal, the result is a 20IRE change with
an appropriate clip setting (as in the
white -insert -over-black example). Gains
of approximately two allow easy control
of soft -key transitions.
Some facilities require a gain of one.
For each increment of 10IRE in key
signal, the result is exactly 10IRE of
change. That is, the key signal is directly
proportional to the mix value in a one-toone correspondence. If a monochrome
ramp key signal is filled with white over
black, the net result is the same image as
the keying ramp. With a gain of two, only half the ramp would be visible.
In reality, the requirement is that the
exact gain is known and is suitably low
that subtle mix variations can be controlled. Not every keying system with
this capability allows control over this
type of key to come from the switcher.
Adjustments are made by changing the
key video rather than adjusting keyer
controls. All in all, the best keyer will
have low -gain adjustment and yet allow
adequate control of clipping, regardless
of what gain level has been used.
Key decisions
A special effects system inserts color bars into
the cloud background. With key softness
added, sharp edges are removed.
72
Broadcast Engineering
A low-gain RGB chroma nulled key places the
flowers and vase over bars. With high gain,
the flowers remain realistic, while the vase
takes on a surrealistic aspect.
September 1986
www.americanradiohistory.com
Analyzing production requirements
allows you to determine how important
the keying factors are to your applications. Beyond simple titling, most users
could benefit from a linear keyer. High gain, fine -discrimination keys; natural edged keys; exactly linear mixed key
levels and exactly controlled proportions
of the key mix would allow you to perform a variety of keying applications.
All the criteria should be examined in
the evaluation of any piece of equipment. Your major concern, particularly
in purchasing a new switcher, is deciding
on the capabilities you require today and
planning for what you'll need tomorrow.
At issue is that future equipment and production techniques may make even
heavier demands upon any keyer's flexibility and accuracy.
I ='. 4)111
SHOOT
IT.
Take your best shot with Thomson Betacams,
studio cameras and field cameras.
SHAPE IT.
Create your best ideas on Vidifont Character
Generators/Paint and Graphics Systems.
SCAN IT.
Digitize, process and store your best slides on
the Thomson TTV 2710 slide scanner.
PICTURE (TALL.
WITH THOMSON.
QTHOMSON-CSF BROADCAST, INC.
37 Brownhouse Road
Stamford, CT 06902-6303
Tel: (203) 965-7000 TWX: (701) 474-3346
Circle (50) on Reply Card
www.americanradiohistory.com
Wiring an audio -video
production facility
By Edgar Lee Howard
Properly wiring an audio -video facility requires more than a reel of cable.
If you don't know what you're doing, there are pitfalls at every connection.
SOURCE
RESISTANCE
It should come as no surprise to most of
you that the systems in the broadcast
business are not all fused together into
one giant black box. Rather, broadcast
facilities consist of a myriad of small
black boxes, interconnected with each
other and with the outside world. These
days, more time is devoted not to designing and building these black boxes, but
to mounting them in racks and connecting them into systems.
There have been many technical
changes over the years. Gone is the
cotton -covered wire. Gone is the big, fat
RG/11, with its solder-on, screw-on connectors. Gone is the enigma of all audio
interconnects, the Christmas tree-and
with it, the melted insulation and burned
fingers. On the way to well -deserved extinction are most solder -type connectors.
They are being replaced with neat crimp on units that are not only faster, but more
reliable.
Figure
1. A simple current loop consisting
a generator and load.
of
WIRE LOSS
WIRE LOSS
.
_
Figure 2. This circuit shows the addition of a
source resistance and wire loss, which causes
a voltage drop.
lems will be created. Interconnecting
equipment can produce noise, distortion
and even dangerous conditions. If you
are to avoid these potential problems in
your installation, you must understand
the theory behind proper interconnection techniques.
Figure 1 shows a simple current loop,
with the same instantaneous current circulating in every part. All the voltage
generated appears up across the load.
Figure 2 shows a more realistic situation. Wires have resistance and,
therefore, some loss. Generators are not
perfect, and they too have losses. This internal loss is shown as a series source
resistance in Figure 2. Most active
devices are single -ended. Their inputs
Interconnection theory
broadcast system, several
common elements exist. For one thing,
the total system is composed of a large
number of individual components. Many
of these components, such as tape
machines, audio consoles and cameras,
can operate as stand-alone devices.
However, they are of little use when
operating alone. For broadcast equipment to be useful, it has to be interconnected with other devices. Unfortunately, the interconnection process is complex and fraught with pitfalls.
To connect the broadcast equipment to
other devices, cable or wire is used.
Paired and shielded wire typically is used
for audio, and coaxial cable is used for
video. In each case, the specific wiring
requirements are different. However, the
basic task is the same: to deliver signal or
power to other broadcast equipment.
Whenever two devices are connected
together, there is the chance that prob In a typical
Howard Is supervisor of maintenance and systems
development for WOSU-TV, Columbus, OH.
74
Broadcast Engineering
R
RACK
RESISTANCE
LOAD
Figure 3. Mounting two
LOAD
sets of generators and loads in the same equipment rack can cause circulating currents to be exchanged between the devices.
September 1986
www.americanradiohistory.com
XOA1 IS GREAT
LAND OF
THE
MIDNIGHT SUN
George Miller lives in Alaska and shoots documentaries. So half the year
he's shooting at night.
That's why he replaced the camera he was using with a Sharp XC-Al. The
picture is amazingly quiet. Even when he
goes to 18db gain.
And thanks to all the information the
XC-Al displays in the viewfinder, George's
job is a lot easier. Step-by-step instructions
coach him on what to do, then disappear or
move to one corner automatically.
Of course, George realizes that the
XC-Al can't do everything, so he still keeps the camera he replaced with it for one
very important job-he uses it to anchor his boat.
Sli4AR P
FROM SHARP MINDS
COME SHARP PRODUCTS`'
For more information call (201) 529-8731. Write Sharp Electronics Corp., Professional Products Division,
Sharp Plaza, Mahwah, NJ 07430. Or visit your local Sharp dealer. ©1986 Sharp Electronics Corporation.
Circle (51) on Reply Card
www.americanradiohistory.com
and outputs usually are referenced to the
same common point. Therefore, you can
assume the lower end of the generator
and the load are connected to the local
chassis ground.
What happens now? Well, for the dc
and low-frequency ac cases, there is still
a simple current loop, so some of the
signal from the generator develops
voltages across the two wire resistances.
This reduces the signal developed across
the load resistor, which is called wire
loss. Notice that there is a signal (voltage)
drop across the lower conductor because
of the wire loss. Each end of the lower
conductor is connected to each chassis
ground. The two chassis (generator and
load) are now at different potentials.
If the generator and the load both are
installed into the same equipment rack,
the resistance of the rack frame will appear as a parallel current path to the
lower conductor. At first, this might
seem to be an advantage, in that the
rack-frame path somewhat decreases the
losses in the lower conductor. However,
consider what happens if there are two
pairs of equipment chassis mounted in
the same rack. (See Figure 3.)
Notice that each pair of chassis
generates a voltage drop across the rack
resistance. However, each pair sees the
voltage drop of the other pair as a part of
its own current loop. If you turned off
one of the generators, you'd hope that its
Wn,
LINE -BLACK
ELK
WIRE RESISTANCE
MAINS
NEUTRAL-WHITE
WHT
POLE
TRANSFORMER
I
GREEN
NEUTRAL
EARTH GROUND
AT TRANSFORMER
DROP
STATION
Figure 4. A typical primary power installation. Shown are four loads across one
primary feed.
CHASSIS
BLK
WHT
GREEN
/J7
CHASSIS
/ff
-
CHASSIS
companion load would see no signal.
Unfortunately, as long as there is signal
current flowing in the rack resistance, a
voltage will be developed. This voltage
will cause some current to circulate even
in the circuit whose generator has been
de -energized. You have just created
crosstalk. Although the signal levels may
be small, they still exist and can become
a real problem, as you'll see later.
Primary wiring
Even worse signal contamination can
result from improperly installed power
systems. Figure 4 illustrates a typical
primary distribution system. For most installations, there is a pole- or pad -
mounted transformer that develops the
CHASSIS
120V, 240V or 3 -phase 208V service
your facility uses. For reasons probably
more historical than sensible, one leg of
the load side of this transformer is
grounded. For single-phase service, this
means that there is one hot wire and one
neutral wire. The hot wire is usually
black and the neutral wire is usually
white. The neutral wire is close to
ground potential. For safety reasons,
fuses or circuit breakers are installed in
the hot or line path to each major equipment load.
Why do Jensen Transformers have
Clearer Midrange and Top End?
The high frequency rolloff of a Jensen
Transformer is optimized, by computer
analysis, to fit the Bessel Low Pass Filter
response. This means minimum overshoot
and ringing and flat group delay for best time
alignment of all spectral components of the
musical waveform.
In
55
129
4
257
153
321
449
3135
512
DATA POINT
-
OTHER
JE11P-1
other words, the harmonics arrive
at the same time as the fundamental
+.3
STEP WAVEFORM
frequency.
9.2
The result is a clear midrange and top
end without the harsh, edgy sound which
has been one of the most objectionable
u
25.0
TIME
u
31.3
u
37.5
u
03.0
u
99.9
é
u
(sec)
sonic complaints about transformers.
There's no "midrange smear."
Only Jensen has this benefit of hi -tech
computer optimization.
GROUP DELAY
Visitors by appointment only Closed Fridays.
10735 BURBANK BOULEVARD
NORTH HOLLYWOOD, CA 91601
(213) 876-0059
ift
jensenINCORPORATE
transformers
D
Circle (52) on Reply Card
76
Broadcast Engineering
September 1986
www.americanradiohistory.com
T
CI IECK
A MONT
TS
A
A
PUT1 IT
AS
The only colors you'll see on these Sharp monitors are
true colors.
Because they both have a shadow mask CRT with U.S.
controlled phosphors.
Plus a comb filter that cuts
cross -color interference.
They also have 600
lines of resolution, so the
picture is as sharp as the
color is accurate.
Plus multiple inputs,
including RGB, that let
you change sources at the
flick of a switch.
And two time constants, so you can analyze
VTR reproduction.
All for $3,500 for our 13 -inch model and $4,300 for our 19 -inch.
Or for $770, there's our 9 -inch utility color monitor for remotes and
editing. With many of the features our larger models have.
So contact your local Sharp dealer, call Sharp at (201) 529-8731, or
write Sharp Electronics Corporation, Professional Products Division,
Sharp Plaza, Mahwah, N.J. 07430.
And the next time you're checking out
monitors, remember:
Next to Sharp, any other monitor is the
Our 9" utility color monitor
for remotes and editing. next best thing.
AN Equipment, Audio, Banking Systems, Broadcast Cameras, Calculators, Cash
Registers, Computers, Copiers, Electronic Components, Electronic Typewriters, Facsimile,
Medical Products, Microwave Ovens, Televisions, Vacuum Cleaners, Video Recorders.
Prices quoted are suggested list prices. 01986 Sharp Electronics Corp.
Circle (53) on Reply Card
www.americanradiohistory.com
SHARP
FROM SHARP MINDS
COME SHARP PRODUCTS"
If a load such as an equipment power
transformer is attached, current will flow
in the loop and both transformers. As
might be expected, IR drops will occur in
both the line and neutral conductors.
Because this is primary power, and not
video or audio signals, there are amperes
of current flowing in these wires. This
current can produce several volts of drop
as a result. Zero gauge wire has a
resistance of approximately 0.112 per
1,000 feet. A 500 -foot feeder would have
1,000 total feet of wire. If 100A is flowing
in the circuit, a voltage drop of approx-
imately 10V, 5V each way, is produced.
You can see that IR drop in primary
feeders can be significant.
If the power transformer primaries
were the only elements connected to the
power distribution point, you'd have few
problems. However, that is not usually
the case.
Most equipment chassis are connected
to the station ground system. This
ground should be an earth ground.
Remember that one side of the primary
power transformer also is connected to
earth ground. The neutral wire, which
connects the two transformers as shown
in Figure 4, develops several volts of
drop because of the resistance in the
wire. A third wire now comes into play.
This third wire, called the safety
ground, is not connected to the neutral.
Performance ...
NMI
Performance is a word often heard in the audio industry. Whether it is
consumer Hi-Fi, studio broadcast or communication equipment,
recent years have seen tremendous improvements in performance.
This creates a need for more performance in your audio measurement
equipment.
The Amber 5500 Programmable Audio Measurement System meets
the challenge with a performance level among the best in the industry
(distortion to below 0.001 %/ - 100dB, noise to below luV/ - 120dBm,
balanced generator output over 30V/ + 30dBm). And in another
measure of performance - thoroughness and speed of testing - the
5500 excels as well with measurements to virtually all world standards, NAB, AES, CCIF, CCIR, CCITT, IHF, DIN, SMPTE, three to
ten times faster than other systems. For ATE applications, the 5500
can be easily driven by your controller via either the GPIB/IEEE-488
or serial RS -232 port. To ensure that the 5500 continues to excel in
performance, its unique modular architecture lets the system grow
and change as the industry advances.
Improve the performance of your product by using a high performance audio test system. Ask for our comprehensive technical
brochure on the Amber 5500.
Amber also makes one of the most popular portable high
performance audio measurement systems - the 3501. Half the
weight and size of comparable instruments, the 3501 has one of
the best reliability records in the industry.
Amber Electro Design Inc.
amber
4810 Jean Talon West
Montreal Canada H4P 2N5
Telephone (514) 7354105
Telex 05-827598
US Toll free 800-361 3697
Circle (16) on Reply Card
78
Broadcast Engineering
September 1986
www.americanradiohistory.com
Generally, the safety ground (which is
usually a green wire) is connected to the
station ground through the grounded
equipment chassis.
Consider what can happen if the safety
ground is connected to the neutral at the
power panel. Suppose there is a drop of
5V in the neutral between the pole
transformer earth ground and the power panel neutral. Remember that the green wire safety ground has just been connected to this same power-panel neutral.
The safety ground is also connected to
the equipment chassis, which is connected to the station ground and in turn
to earth ground. An ac circulating current has now been developed through
the station ground, in parallel with all of
those interconnects discussed previously.
This combination of signals adds to the
total noise problem in the facility. Connecting the safety ground to the power panel neutral is a common mistake.
The safety ground is by far the worst
culprit when it comes to generating
noise. However, it is not the only one.
Anything that permits current to flow
from the primary circuit of the power
transformers into the chassis ground can
cause noise. Some equipment is supplied
with resistor-capacitor bypass networks
connected between the line side of the ac
input and the chassis ground. This bypass
network simply couples ac noise directly
into the equipment chassis.
Another noise source is a noise suppression filter that decouples both sides
of the ac line to the chassis. To a lesser
extent, the winding capacitance between
the power transformer primary and the
transformer core or electrostatic shield
also can couple ac energy into the station
ground system.
Solutions
How can you get rid of these noise
sources? Check within each piece of
equipment to be sure nothing but induc-
tance in the power transformer couples
energy out of the primary circuit.
Remove all of those little RC bypass networks whenever you find them. Ensure
that RF filters bypass from line to neutral
and never to the chassis.
Check the capacitance of each power
transformer primary to the electrostatic
shield. Be sure the end with the most
capacitance is connected to the neutral.
More capacitance but much less voltage
means that less energy is coupled into
the chassis. Above all else, never connect the safety ground wire to anything
but the station ground.
If you can get away with it, eliminate
the safety ground wire altogether and
wire all of the ac distribution with two
conductor cables. Equipment mounted in
metal racks and bonded to a technical
ground is unlikely to elevate itself
dangerously above ground, so no safety
hazard exists.
If you have to meet local code re Continued on page 82
//////%%%%///%//////1111111111\\\\\\\\\\\\\\\\\\\\\\O\\
nulnnnNALVZCe
®ROMDE85CNWARZ
uli.
mUklv
HEMEKT
LEVEL
EEE
1
OOIATIOO
r/ ru 1.
aar/
..
FUECTIOO / CAVA
s,r rn s 1
,
Tr
1
I
1
IOINPUTEEOOF
ORWT
:i
(4-...)
IF+E
0. 1,
I',¡rl
1
urn
......
..w
eIF
n
1
I
1
.
El
MT
I
E
(-I
MO--
ï-
.IOIWE
'... ñ
... .n
C'....
.. ...
,..,.
.../
«,.
FILTER
,
DETECT
WOW OFLUTiEE
...
a
i
..
t«..1...,.,
l-)
n
a
VIII
.
/NOISE
'.'.' ....
nn
C2.
7
o
9
4
6
e
1 '"
nn.
-
' iñ.
L=
=
:
..
L
>
l
L
the high notes of our audio specialist:
frequency range 10 Hz to
100 kHz, 3 Hz to 300 kHz
(-3 dB)
Audio Analyzer UPA is the intelligent answer when you need a system -capable
psophometer with integrated frequency counter. With options you can turn
it into a complete audio test setup, with weighting filters for every application.
voltage range <10 µV to 300 V
with 1µV resolution
distortion <0.003 to 100 % or
-90 to 0 dB
wow & flutter 0.003 to 5
Write or call for full details of UPA Audio Analyzer
ROHDE &SCHWARZ
polarad
Rohde & Schwarz-Polarad, Inc., 5 Delaware Dr., Lake Success, N.Y. 11042
Tel: 516-328-1100 TWX: 510-223-0414
Circle (55) on Reply Card
www.americanradiohistory.com
D-
Cairn Broadcast
to meet
PV40x1
for 30mm and 25mm cameras.
The Olympian-proven at the 1984 Olympic
Games, its 40X reach is perfect for sports and
all outdoor broadcast operations.
Focal length: 13.5-540mm (27-1080mm w/built-in
extender)
Max. Relative Aperture*: 1:1.7 through 270mm
1:2.8 at 540mm
25mm format
P18x15BIE for 30mm and 25mm cameras.
The Widest-a very wide 60° angle of view
plus incredible edge -to-edge sharpness,
fidelity and sensitivity. Supplied with 1.5X and
2X built-in extenders plus pattern projector.
Focal length: 15-270mm (30-540mm w/2X extender)
Max. Relative Aperture*: 1:2.1 through 218mm
1:2.7 at 270mm
25mm format
Your
PV14x12
igh Resolution Lens for 30mm
and 25mm cameras.
A Unique Design- featuring extensive use of
Fluorite lens elements, this lightweight, compact
14X studio lens provides high sensitivity and
critical sharpness at all focal lengths.
Focal length: 12.5.175mm (1.5X and 2X extenders built-in
Max. Relative Aperture*: 1:1.6 at all focal lengths
'25mm format
J15x8.5BIE for 2/3" cameras.
2/3" Economy-full utility for all studio
situations, combining a 15X zoom ratio with
an M.O.D. of under two feet, a 54° angle of
view and high sensitivity throughout the range.
J18x9BIE for 2/3" cameras.
Greater Reach, Lighter Weight-nothing
matches the 18X zoom power of this lens-and
it weighs less than 4 lbs.! It increases the
flexibility of any portable camera.
Focal length: 8.5-128mm (17-256mm w/built-in
extender)
Max Relative Aperture: 1:1.6 at all focal lengths
Focal length: 9-162mm (18-324mm w/2X extender)
Max. Relative Aperture: 1:1.7 through 116mm
1:2.4 at 162mm
www.americanradiohistory.com
J14x8 BIE High Resolution Lens for 2/3" cameras
Super wide (60°) and super sharp from corner-to corner. This compact lens also provides a 14X
zoom ratio and built-in 2X extender.
Focal length: 8-112mm (16-224mm w/built-in extender)
Max. Relative Aperture:1:1.7 through 91mm
1:2.2 at 112mm
TelevisiontheLenses.
future.
needs. Now and in
J45x9.5 BIE fo- 2/3" cameras_
Incredible45X reach with you 2/3" cameras
Perfect for sports and all outdoor E.F.P.
applications.
-
Focal length: 9.5-430mm (19-860mm w/built-in
extender)
Max. Relative Aperture: L1.7 through 201mm
1:3.0 at 40omm
J25x11.5
3reater Peach-a 25X zocm lens designed
specifically for 2/3" cameras. The power and
scope of 1" systems, the economy and
efficiency of your 2/3" cameras.
Focal length: 11.5-288mm (23-576mm w/2X extender)
Max. Relative Aperture: 1:1.6 th-ougln 220mm
1:2.1 at 288mm
J13x9BIE for 2/3" cameras.
The Portable Standard-used by cameramen
around the world under all conditions,
the J13x9BIE is a proven performer with
superior sharpness and sensitivity.
J15x9.5 for 2/3" cameras.
Quality plus Economy-you can't buy more lens
for less money. Lightweight and sensitive, it meets
the needs of both cameramen and accountants
yet lives up to its Canon name.
Focal length: 9-118mm (18-236mm w/2X extender)
Max. Relative Aperture: 1:1.6 through 99mm
Focal length: 9.5-143mm
Max. Relative Aperture: 1:1.8 through 112mm
1:2.3 at 143mm
1:1.9 at 118mm
J20x8.5BIE for 2/3" carreras.
Two Ass gnments-use a 13 < zoom for EN 3.
use the J20x8.5BIE for studio or outdoor
broadcast assignments-with the same 2/3"
camera!
Focal length: 8.5-170mm (17-340mm w/2X extender)
Max. Relative Aperture: 1:1.6 through 130mm
1:2.1 at 170mm
J3x6 B Ultra Wide -Angle Lens for 2/3"
cameras.
The widest of the ultra -wide zooms at 72.5?
this incredible 8X lens also has a M.O.O. or
only 11"-it's great for interviews!
Focal length: 6-48mm
Max. Relative Aperture:1:1.7 through 33mm
1:1.9 at 48mm
Cau
Optics Division
Canon USA, Inc. Head Office: One Canon Plaza, Lake Success, NY 11042 #516) 488-6700
Dallas Office: 3200 Regent Blvd.. Irving, TX 75063 (214) 830-9600. Chicago Office: 100 Park Blvd., Itasca, IL 60143 (312) 250-6200
West Coast Office: 123 Paularino Avenue East, Costa Mesa, CA 92626 (714) 979-6000
,,Iit,
Canon Canada, Inc., 6390 Dixie Road. Mississauga, Ontario L5T1P7, Canada (416) 578-27:30
Circlle (56) on Reply Card
www.americanradiohistory.com
$A..ne
R
o
///
COMMON MODE SIGNAL
Figure 5.
Using transformers can isolate circulating currents, preventing noise. Here, the
common -mode signal is never coupled to the audio signal.
Continued from page 78
quirements, use the electrical scheme
that is used in hospitals. These areas
meet special safety requirements and use
a separate technical ground that has no
connection to the electrical power
distribution system Sometimes called
orange ground systems, they are more
expensive to implement than the green
ground systems, but meet safety code requirements while preventing circulating
currents in the equipment grounds.
Or, if the ground to the signal path is
eliminated, circulating currents cannot
flow. This will prevent noise problems.
For audio -range signals, this ground path
is eliminated easily. Simply use
transformers to interconnect the equipment, as shown in Figure 5.
The current loop in the interconnecting wires remains, but the current is entirely isolated from the grounds and from
any common -mode voltages and cur-
rents. Also note that two transformers
aren't necessary. Figure 6 achieves the
same current loop independence with
only one transformer. Having the loop
grounded at one point does not couple
noise into the loop, because only one
connection is made. This is fortunate,
because transformers tend to become
large and expensive when they are required to pass full -bandwidth audio
signals at high power levels. Transformers, if they are used at all, belong in
the low -power input stages.
High -frequency noise
These techniques are fine for low fre-
quencies. At
higher frequencies,
however, stray capacitances begin to
manifest themselves. Figure 7 shows
that, with high frequencies, capacitive
leakage paths are possible. For instance,
a path from the high side of the loop to
the chassis ground provides a complete
Signal distribution
Now that you have a better idea of the
problems associated with power distribution, look at signal distribution. Recall
from Figure 2 that the grounding prob-
lems began when the chassis grounds
were interconnected on the generator
and the load. If nothing is connected to
the equipment chassis, circulating currents in the grounds are not a problem.
o
o
///
Figure 6.
COMMON MODE SIGNAL
///
A single transformer can prevent circulating noise currents as shown here.
PlffflE
CHASER
... a Sound investment
From
The Smart Audio Time Base Corrector
...
Definitely Discriminating!
11ItilIllt NIIItNNI
Stereo is everywhere ... except in the listener's ears.
Less than 50% of all radio receivers are stereo; most
televisions are mono. So mono compatibility along
with high quality stereo is extremely important to your
success in the marketplace.
The Howe 2300 Phase Chaser GUARANTEES MONO
COMPATIBILITY AND STEREO INTEGRITY
everywhere in your audio chain, simply *.
FEATURES:
IN
Corrects time delay errors up to ±150 microseconds
Original stereo information remains unchanged
Active balanced I/O; XLR connectors
Programmable missing channel sensing and
correction
Channel polarity error detection and correction
2300 Central Ave., Suite E
Boulder, Colorado 80301
Call Bill Laletin at 1-800-525-7520
to place your order.
*No pilot tone or prior encoding required.
Circle (57) on Reply Card
www.americanradiohistory.com
'
A TOUGH /CT TO FOLLOW
Genesis
1TM
With ACT 1TM$27,990
Genesis 1 ACT 1, Microtime's high quality, low-cost digital effects system
increases creative capabilities to your imagination's limit. Create through
self -prompting, icon-driven menus and instructions for sequences involving
moves, freeze, flips, tumbles, posterize, shadow, variable aspect ratio,
XY mosaic, strobe, and source change.
ACT 1 offers:
3 -Axis joystick control
O Keyframe creation of sequences
Smooth curvilinear movement
Frame accurate duration of a sequence
Routing switcher interface for dual input switching
when flipping and tumbling
Three levels of sequence storage:
RAM, internal and portable
Genesis 1 ACT 1...A user-friendly digital effects system for your video
productions. An ACT not to be missed at $27,990.
Genesis
1
MICROTIME
A Subsidiary of ANDERSEN GROUP
Northeast, Ray Bouchard (609) 896-3716
Central, David Everett (312) 934-9191
Southcentral, Steve Krant (214) 644-0232
Southeast, Jerry Rankin (404) 979-4437
Western, Chuck Bocan (714) 989-4433
Microtime, Inc.
1280 Blue Hills Avenue
Bloomfield, CT 06002 USA
Tel: (203) 242-4242
TWX: 710-425-1165
Genesis
1
and ACT 1 are trademarks of Microtime, Inc.
Circle (58) on Reply Card
www.americanradiohistory.com
ground currents.
The sending end of the shield and the
chassis are now at the same potential,
and can't couple noise. The receiving
end, however, is still able to couple stray
energy as before, so the improvement is
limited to approximately 6dB. This
theory indicates that when shields are
used, they should be grounded at the
sending end only.
Balanced circuits
Look again at the noise problem.
Recall that signal contamination noise
comes from currents flowing through the
load due to capacitive coupling between
the hot wire and the local ground. Consider how you can use a balanced output
to your advantage.
Figure 10 shows a symmetrical or
balanced output stage with identical
COMMON MODE NOISE
Figure
7. Capacitive leakage paths develop when high frequencies are present. These paths are
represented by Cure and 2
circuit for ground signals to flow. Some
of these high frequencies also flow
through the input transformer primary
and, therefore, can add noise to the
desired signal. The higher the frequency,
the lower the effective impedance and
the greater the signal contamination.
What can you do about it? You could
electrostatically shield the interconnecting wires and tie the shield to only the
sending end's chassis ground, as shown
in Figure 8. With this scheme, both ends
of the stray capacitors are now at the
same potential, so no ground signal currents flow. Notice, however, that if the
shield is grounded at only the receiving
end, as in Figure 9, you have just about
the worst possible case of capacitive
7
SHIELD
TOD TCD
D
C
CD
/77
Oo
TCD
Co
It
CD
(7)
COMMON MODE NOISE
Figure 8. Grounding the cable shield at the sending end proves to
reducing the effects of stray capacitance.
be an effective method
NEW PRODUCT! BROADCAST QUALIT.
VIDEO -STEREO AUDIO DA-$595
The DA -5020P video -stereo audio
distribution amplifier from ICM is
perfect for the most demanding needs
of video tape duplication or other
distribution requirements. Its broadcast
quality video section and Beta -VHS
hi-fi quality audio sections are second
to none in performance.
Video specs include an impressive 20
MHz bandwidth, 1/4% P-P differential
gain, 1/a° P-P differential phase, and 80
db S/N ratio. Audio specs are equally
impressive - completely flat bandwidth
from 35 Hz to 25 KHz, better than 90
db S/N ratio, and .05% THD.
Each video and audio section provides
12 perfectly matched outputs from a
single input. Stacking additional DA's
will provide more outputs. The rack
mountable cabinet is 13/4' high. Front
panel screwdriver adjustments and test
points facilitate level adjustments and
high frequency compensation.
Call or write
for additional information!
ICM VIDEO
701 WEST SHERIDAN AVENUE
OKLAHOMA CITY, OK 73126
(800) 426-9825 TOLL FREE
P.O. BOX
26330
12 VIDEO AND 12 STEREO
AUDIO OUTPUTS
VIDEO
Circle (59) on Reply Card
84
Broadcast Engineering September 1986
www.americanradiohistory.com
of
IF TRANSMITTER FAILURE HAS
CAUSED YOU TO LOSE REVENUE,
LET US INTRODUCE OUR INEXPENSIVE
EMERGENCY TRANSMITTER.
what happens at your
station when your FM
transmitter goes down? Or
your studio transmission
link is disrupted? Or a
power loss at the transmitter site occurs?
QEI has an inexpensive
Solve the problems caused
solution. Our low-power
FM transmitter designed for
studio operation can
handle all these emergencies and keep you on
the air. In many cases
you'll retain the majority of
your audience simply because your studio is usually
located more central to
your market than your
transmitter site.
by an STL or main
transmitter failure ... and
do it on a modest budget.
For more information contact John Tiedeck at 609
728-2020. He will put a
package together to meet
your station's needs.
For a small investment
your station will gain
protection against lost
revenues and the embarrassment of discontinued service.
QEI's low -power
transmitters are all
solid-state and are
available in 150w,
300w or 500 -watt
power output levels.
No warm-up
-
A
Coverage using QEI
studio location transmitter
Coverage using
station's primary transmitter
B
is
re-
quired. They are on
the air in less than
10 seconds ... and
VtÍ1.5TS40
have hundreds of
thousands of trouble free hours. Virtually silent
in operation, all our transmitters use QEI's famous
675 synthesized exciter.
So
cover yourself with
QEI
a
low-power FM trans-
mitter located at your
studio site ..
.
RM
TRANSMITTER
QEI Corporation
One Airport Drive
P.O. Box D
Williamstown, NJ 08094
Phone: 609-728-2020
Call Toll Free 800-334-9154
QEI Corporation
Circle (60) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering 85
SHIELD
COMMON MODE NOISE
Figure 12. Small trimmer capacitors can be
Figure 9. Grounding the cable shield at the receiving end can still couple ground noise into the
used to balance out any stray capacitance.
system.
Inductive coupling
generator or source impedances, Rg , in
each output line. These generators produce out-of -phase identical signals on
each output with respect to the local
chassis ground. The interconnecting
wire is terminated as before, and symbolic stray capacitances are shown con-
capacitors (see Figure 12) could be installed from each side of the input to
local ground, and one or the other could
be adjusted to balance the stray
capacitance or the magnitude of the
source resistance. This is sometimes
necessary to deal with adverse sources,
COMMON MODE SIGNAL
Figure 10. The balanced source and load configuration shown here can still suffer from stray
capacitance problems.
nected to the terminating chassis.
Again, this is a worst -case example.
Figure 10 has been redrawn to give a
better idea of what is happening. The
new schematic, shown in Figure 11,
treats the generators, stray capacitances,
and ground-noise sources as a bridge
configuration. If the R, values are equal
and the CSTRAY values are equal, then you
have a balanced bridge. This means that
points A and B are at the same potential
with respect to the ground noise.
COMMON
MODE
SIGNAL
CSTRAY,
CSTRAYZ
02
Figure 11. Balanced source and load
redrawn in a bridge configuration.
Therefore, no ground noise -induced currents can flow through the load.
Assume that the source resistances are
the same and the stray capacitances are
the same. If they aren't, suitable variable
86
such as telephone lines.
Other noise sources
If you change the label of the ground noise generator and think of it as just
some other signal, then you can use this
same model to consider the effects of
capacitive coupling other signals into the
circuit. The model and the results are the
same. If the source resistances are equal
in the circuit, and the stray capacitances
are the same between the other signal
and each of the conductors, then no
interference-signal energy can exist
across the load. Therefore, there will be
no crosstalk.
The key is having equal -value stray
capacitances from the outside sources to
the two conductors. The simplest way to
ensure this is by using twisted pairs of
wires for the interconnects. Over any
reasonable length, the tightly twisted
conductors both occupy the same space.
The two conductors are both equally
close to any adjacent noise source, so
they have identical stray capacitance
values. When driven and terminated in a
balanced manner, twisted pairs, even unshielded pairs, are virtually immune to
capacitive crosstalk. In a similar manner,
balanced-driven twisted pairs produce
little coupling into other conductors.
Again, the two equal capacitive components of coupling are out of phase and,
therefore, cancel each other.
Broadcast Engineering September 1986
www.americanradiohistory.com
Although this article has focused on
the effects of capacitive coupling, induc-
tive coupling effects also are present.
The current loop discussed previously
can be thought of as a single-turn winding of a transformer. Therefore, any
magnetic flux passing through this loop
will induce a current in the wire and
create unwanted signals into the load.
Shielding, whether woven mesh or foil,
is not composed from magnetic
materials, which makes it of little use
against magnetic flux.
Fortunately, the twisted pair is the
answer again. In a tightly twisted pair
there is little space between the conductors, so the area of the one turn loop is
small, and little flux can pass through it.
Also, because the wires are twisted, the
direction in which current is induced by
the applied magnetic field reverses for
each half-twist of the wires. Over a large
number of twists, the net -induced current is quite small because each half-twist
cancels out the one before it.
Twisted pairs are also virtually immune to inductive crosstalk. Twisted
pairs generate little net magnetic flux
because the contributions from successive half-twists are out of phase and
cancel out.
The major points that have been
discussed are that:
Twisted pairs should be used to
eliminate inductive crosstalk.
Twisted pairs, shielded or not, should
be used to eliminate capacitive crosstalk.
The circuit must be driven balanced with
equal source resistances and terminated
in a true balanced input.
Electrostatic shielding, if present,
must be grounded only at the sending
end.
Proper operation is contingent upon
terminating the twisted pair with a
balanced input. So far, this article has
discussed using transformers to balance
the circuits. Even though the transformer
has a number of inherent problems, such
as poor frequency response and high
distortion, the floating -primary input
transformer is virtually insensitive to the
ground -referenced inputs (ground noise
and crosstalk). This insensitivity is possible because there is no current path from
the primary to ground. Only an imbalance in primary winding capacitances
to ground from the windings can upset
Continued on page 90
-
Whatever your imaging application medical or
industrial diagnostics, machine vision, broadcasting or
CCTV, surveillance or robotics Amperex is eager to
work with you.
The resources available to you at our Slatersville, Rhode
Island facility include our Research and Development
and Applications Engineering Departments. Both are
integrated with a "super clean" Class 100 manufacturing
plant. In addition to offering a broad range of imaging
devices including the newest solid state image sensors,
Amperex is continuously developing new technologies
and adapting existing products to the
specific needs of our customers.
The Amperex reputation as an image
maker is based on supplying the right
products for your imaging needs. For
more information call or write Imaging
Products Group, Amperex Electronic
Corporation, Slatersville, Rhode Island
02876. (401) 762-3800. A North American
Philips Company. Outside the U.S.A. contact:
Philips Electronic Components and
Materials Division, 5600 MD Eindhoven,
The Netherlands.
-
The
ma
High Resolution Diode Gun'
Plumbicon° TV Camera Tubes for
diagnostic imaging.
Amperex
Amperex Imaging Products
...we see things your way.
Pyroelectric DTGFB vidicon tube
with 8-14 micron sensitivity for
thermal imaging and 24 -hour
surveillance.
Electro -magnetic coil
assemblies.
Vidicon
tubes low
cost general purpose
-
to fiber optic
special window
types.
Image intensifier tubes
including microchannel
plate and proximity
focused types.
Solid state
thermal imaging
devices for 3-5
micron and 8-13 micron
applications.
High resolution frame
transfer CCD image
sensors for color and
black and white applications.
Diode Gun and Triode Gun Plumbicon camera
tubes for color or general purpose imaging.
Circle (61) on Reply Card
www.americanradiohistory.com
Newvicon°
high -sensitivity
camera tubes for
low light and 1
micron IR imaging.
NO PATCHING
QUESTION IS TOO
TOUGH FOR ADC'S
"PANEL Of EXPERTS:
MODERATOR: "Thank you, and
welcome. First question, please
don't hesitate to give us your
best shot:'
QUESTION #1: "OK, Panel, I
need patchbays that keep my
racks neat and tidy, without a lot
of cabling clutter. And I need to
install them quickly and securely.
Any suggestions?"
PROPATCH: "Sure- try ADC
Pro Patch Mark II patchbays. They're
fully enclosed, and all the terminations are QCP punchdowns on the
back of the box. Fast installation is
one reason we're the panel of
-
experts."
QUESTION #2: 'This one's
tougher, Panel. I need to terminate
www.americanradiohistory.com
my patchbays in the bottom of
the rack, but I want my jacks
protected'
BJF: "No problem. ADC's
Broadcast Jackfield (BJF) Mark II
series gives you the best of both
worlds. They feature Ultra Patch
termination panels with QCP punch downs on the end of a harness. So
you can terminate your cabling
wherever it's most convenient. The
patchbay chassis supports the cable
harness and covers the jacks."
QUESTION #3: "What about
when your budget's tight? I need
quality patchbays, but I've got a
small facility and I can't spend
a lot of money'?
PATCH KIT: "Our Patch Kit is
exactly what you're looking for It's
a Broadcast Jackfield Mark II chassis
without the cabling. Just add your
own cable and you'll have it made.
And you'll save money
by doing it yourself."
instead. Because it's modular; you
can install the number of video and/
or audio modules you need- no
more, no less. And it's expandable."
ve,
QUES11ON
#5: "I'm
convinced,
Panel. You're
`z,
QUESTION #4:
"Let's see you answer
this one, Panel. I have
a small off-line suite
and I need to patch a
few audio circuits
AND a few video circuits. If you want me
to buy two dozen circuits at a
time, forget it'?
VAMP: "Don't buy more patching
than you need. Buy an ADC Video/
Audio Modular Patchbay (VAMP)
great patch -
bays. But doing
designation
strips drives me
crazy"
MODERATOR:
"We've got the answer- our Self
43.
Adhesive Identification Labeling
System (SAILS for short). It's a
special computer -printable,
adhesive -backed polyester label.
Circle (62) on Reply Card
SAILS won't discolor, smear or tear;
and they're removable. You don't
even need special software to print
on them. You'll find SAILS on
every ADC patchbay. Any more
questions?"
QUESTION #6: "Just one.
Where can I buy ADC patchbays
in a hurry?"
MODERATOR: "Call us at (612)
893-3010, and we'll give you the
name of your nearest ADC stocking
distributor Like everyone on our
panel of experts, he really delivers."
'
Telecommunications
ADC Telecommunications, Inc. 4900 West 78th Street
Minneapolis, Minnesota 55435 (612) 893-3010
www.americanradiohistory.com
IN
NON -INVERTING
A=
-RF; FORRE= RL; Av
RL
=
-1
Av=1
+ RF;FOR RF
Rte;
A=1+1=2
Figure 13. Inverting and non-inverting operational amplifiers.
Continued from page 86
the isolation.
The transformer's center tap should
not be connected to anything. If it is
grounded, the transformer's rejection of
ground -returned signals or noises
depends on the precision with which the
center tap is placed in the electrical
center of the winding.
Active circuits
many instances, active circuits can
be used in place of transformers. If the
ground -return signals are common to
both input lines and are reasonable in
terms of level and frequency, the noise
can be suppressed by active circuits.
The operational amplifier (shown in
Figure 13) has two operational modes:
inverting and non -inverting. The resistor
connected to the positive input does not
affect the gain and is usually selected to
minimize offset in the amplifier.
Figure 14 illustrates a unity gain line
receiver with immunity to common mode signals. This can be demonstrated
by taking each input signal through the
circuit separately, and then adding the
resulting outputs. The top input, consisting of +signal, +noise (+S+N),
passes through inverted with unity gain,
In
as
-(+S+N).
INVERTING
INPUT
+S+N
R
NON -INVERTING
INPUT
-S+N
Figure 14. Balanced, unity gain receivers,
such as the one here, can provide isolation
from common -mode noise signals.
The lower input, consisting of -signal,
+noise (-S+N), is divided by two to
compensate for the circuit's gain of two.
This -S+N signal passes through unchanged, as -S+N. The sum is -2S. The
differential input terms add and the
common -mode terms cancel.
This circuit serves to illustrate that
common -mode rejection is possible without the use of transformers. Unlike the
transformer, which simply ignores
common -mode energy, the active line
90
Broadcast Engineering
receiver must amplify and then cancel
out common -mode energy. The amplifier
also has some maximum signal-handling
capability limit. Common-mode signals
greater in amplitude than this limit will
saturate the amplifier and destroy the
desired signal.
Also, no amplifier is completely free
from distortion. A small amount of noise
will contaminate the signal. The result is
that the -2S output is not pure S, but
rather, includes a noise residue instead of
a perfectly canceled N. In high-noise environments the floating-primary transformer is often still the best answer.
Video
These designs work well for audio
signals, but what about video? Balanced
video coaxial cables are available, but
are usually reserved for long-haul telephone company circuits and other special applications. They are seldom used
in station construction. Fiber-optic links
are also free from common-mode problems, but are not widely used for simple
system interconnects.
Because of the requirements for wide
bandwidth and minimal waveform distortion, video cable is typically driven
unbalanced and terminated at its characteristic impedance. Typically, the shield
is grounded to the chassis at each end of
the cable. By now, you can probably
guess that this will introduce groundnoise currents into the video circuit loop.
It is not possible to truly balance the
coaxial cable. This is because the center
and outer conductors' resistances are different and the stray capacitances are not
at all symmetrical. Even so, ground -noise
currents can be eliminated by terminating the cable with a differential amplifier.
Most of the newer video DAs and similar pieces of equipment have floating
video connectors and differential-mode
input circuitry to make ground -noise
elimination possible. Special care must
be taken when passing video cables
through patch panels and feedthroughs.
If the shield comes into electrical contact
with the local ground, ground noise will
be introduced inadvertently.
Installation notes
The author has had success distributing audio throughout a facility with foil shielded cable (Belden 8451). Ground the
shield, where practical, at the sending
end. Otherwise let it float. Telephonestyle punchblocks are used as terminal
and interconnect blocks. The punch-on
contacts work well even with the strand-
September 1986
www.americanradiohistory.com
ed 8451 wire. The punch-on blocks are
also easy to use.
Mount the punchblocks on the exposed
ends of equipment rack rows where they
will be neatly covered by the rack end panels. Plastic wire channels run vertically next to the punchblocks to contain
the wiring. First strip off the jacket and
cable shield at the base of the rack to
save space in the channels. The red and
black conductors are then tightly twisted
with an electric drill, placed in the plastic
channels, then connected to the blocks.
Build plug-in audio patchpanels by
mounting each jackfield onto a 13/4 -inch
bathtub chassis, with two 25 -pair ribbon
connectors mounted on the back of each
chassis. The top and bottom rows of the
jacks are wired to the top and bottom
25 -pair connectors. Premanufactured or
locally made 25 -pair pigtails carry the
signals to and from the punchblocks.
Even though the pairs are not shielded,
crosstalk is not a problem.
It should be stressed that punchblocks,
25-pair twisted cables, and these installation techniques are for line -level signals.
These techniques should not be used for
microphone-level signals. Microphone
circuits should have continuous shields
and soldered connections all the way
from the microphone to the preamplifier.
Patching microphone -level circuits also
is not recommended.
Swept -video cable should be used in
your installations even though it is more
expensive than RF cable. The swept
cable's solid -copper center conductors
and densely woven shields provide much
lower resistance than other cables. In addition to the lower resistive losses, swept
video cable (such as Belden 8279 or
8281) has been optimized for flat
response in
the video spectrum.
Therefore, this type of cable requires less
equalization than RF-type cables.
Plan ahead
Now that you've covered the basics,
the first step to any wiring project is the
drawing board. You need to carefully
plan the installation. Drawing the proposed facility on paper helps to avoid
costly wiring mistakes.
As you design the system on paper,
look for areas that have the potential for
grounding problems. Are there bulkheads where the video cables can be inadvertently grounded? Are any of the
audio or video cables being carried in
conduit with power cables? Have you
routed any audio or video cables near
primary power transformers?
Use the planning stage to try out different installation and connection ideas.
You need time to think through the project and try to resolve any problems on
paper first-before you have to resolve
them in the field.
Wiring any facility is a challenge.
Carefully planned and executed, however, this kind of project can be highly
gratifying.
I =TA)))I
A monitor to keep
an eye on your video
equipment.
At Camera Mart.
Tektronix 1750 Series Waveform Vector Monitor
No matter how versati e or advanced video equipment is, it must
operate reliably and up to specs.
That's why we at Camera Mart are so impressed with the Tektronix 1750
Series Waveform/Vector Monitor, a brand new, compact unit that monitors
all your other video equipment to make sure everything is working perfectly.
The 1750 Series combines all the conventional monitoring capabilities
plus the ability to perform SCH phasing tasks.
SCH phase and color frame matching is measured directly using the
new SCH MODE. This makes it ideal for production and editing applications
where the maintenance of SCH phase and color frame relationships is critical.
It's new, and, as you'd expect, it's available right now from Camera Mart.
The more you know about video, the more you can
rely on Camera Mart.
The
Camera Mart, Inc.
456 West 55th Street. New York 10019 (212) 757-6977
Telex: 275619 FAX (212) 582-2498
305 Vine St., Liverpool, NY 13088 (315) 457-3703
Sales Service Rental
See Us at SMPTE Booth 1144
Circle (95) on Reply Card
www.americanradiohistory.com
Microphones,
from the inside out
By Tim Schneckloth
The more you know about microphones, the better your station will sound.
Microphones are transducers-nothing
more, nothing less. No matter how large
or small, elaborate or simple, expensive
or economical a microphone might be, it
has only one basic function: to convert
acoustical energy to electrical energy.
With that established, you might
wonder why microphones exist in such a
mind -boggling array of sizes, shapes,
frequency -response tailorings and element types. The answer is simple.
Although the basic function of all
microphones is the same, they have to
work for many different applications and
under various conditions. A transducer
element that works well with a CB radio,
for instance, might be a noisy horror in a
recording studio.
With applications in mind, let's examine some different microphone types,
what's inside them and how they work.
Condensers
Condenser microphones have been
steadily gaining in popularity over the
past decade, and with good reason. They
can be designed to be extremely small
and lightweight, and they can provide
clean, precise, accurate sound reproduction with great clarity. For these reasons,
condenser microphones (such as lavalier
and surface-mount microphones) are
often used for applications in which
unobtrusiveness or high -quality sound
reproduction (such as in studio record-
capacitor. When sound waves strike the
diaphragm, they cause a change in the
spacing between the diaphragm and
backplate, varying the electrical
capacitance above and below a nominal
value. When a dc bias voltage is added,
the capacitance variations are translated
into variations in electrical voltage. The
extremely small capacitance value gives
condenser microphones a high impedance, making it necessary to add an
active circuit that converts the impedance value and makes the signal
usable.
A related technique is used in electret
microphones (more accurately called
electret -biased condenser microphones).
In this case, the condenser's dc bias is
supplied by an electret material, rather
than by a battery or power supply. The
electret material, generally a fluorocarbon polymer, can be a part of the
diaphragm or the backplate, and its electrostatic charge lasts indefinitely.
The increasing popularity of condenser
microphones is largely a function of the
recent improvements in condenser
microphone design. A lot of the problems traditionally associated with these
microphones, (sensitivity to wind and
"explosive" breath, fragility and RF
ing) is a must.
In the world of microphones, however,
there's always a trade-off. To get the advantages of a condenser microphone you
have to put up with a few disadvantages.
These include the necessity of powering
an impedance -converting circuit, a high
degree of sensitivity to wind, a dynamic
92
Broadcast Engineering
broadcast, stage, recording and general
sound -reinforcement applications. In all
likelihood, this trend will continue.
Dynamics
Dynamic (also known as moving coil)
microphones are the real workhorses of
the microphone world. When you consider the pros and cons previously
discussed, dynamics fare well. They can
be built for extreme ruggedness and
reliability, they aren't particularly
temperamental and they don't require a
powered impedance -conversion circuit
or a dc bias charge. Dynamics also have
good sound quality, although they can't
provide the detail and precision of the
finest, most expensive condenser
(dynamics can be built fairly inexpensively). All these factors combine to
make the dynamic microphone popular
in many applications, and to make it the
world's most common, best-known
microphone type.
A dynamic transducer consists of a
lightweight, bobbinless coil (the voice
CASE
TERMINAL
INSULATOR
SPRING CONTACT
REAR ENTRY HOLES
range limited by the impedance converter and the need for shielding against
RF and electrostatic interference.
A condenser microphone's transducer
element consists of a lightweight metal
or metalized plastic diaphragm located
near a metal backplate. This forms a
Schneckloth is marketing communications
dinator for Shure Brothers, Evanston, IL.
noise) can be alleviated by new condenser designs and improvements in
shock mounting and wind/pop filters. As
a result, condenser microphones are being used more and more for virtually all
ACOUSTICAL RESISTANCE
INSULATOR
BACKPLATE
SPACER
DIAPHRAGM
RESONATOR
GRILLE
coor-
A cutaway illustration
of a condenser microphone element used in a unidirectional microphone.
September 1986
www.americanradiohistory.com
THE DESIGN WILL INSPIRE You.
THE NAME WILL IMPRESS You.
THE PRICE WILL CONSOLE You.
UREI has some consoling news for stations with ideas that are
bigger than their budgets: our superior line of broadcast consoles put a better on-air board within your reach.
All nine of our 5, 8 or 12 mixer consoles offer the design and
performance features your on -air staff and engineers are after.
At a price general managers only dreamed of before.
Working jocks and announcers helped us lay out a control
panel that puts you instantly at ease. Phone jacks are logically
placed. Recessed push buttons and gold -contact rocker
switches operate surely, quietly. Cueing and monitoring are
simple, yet versatile. Plus, you choose the attenuators-Penny
and Giles faders, Shallco or conductive plastic pots.
We consulted station engineers to bring you consoles that
perform reliably, adapt easily and install quickly, without special tools or accessories. Hinged panels allow fast access to
plug-in cards and circuitry. And no other consoles in this class
can deliver greater head room, lower noise or less distortion.
Built-in flexibility plus optional accessories such as our copy
stand and turntable preamp mean any UREI console can adapt
to your station's special on -air needs. Standard features include
monitor, cue, headphone amp and cue speaker. Reliability is
built-in too. Because UREI has been researching and advancing
broadcast products for over 25 years.
UREI Broadcast Consoles. Why make do with less when you
can afford to move up to more? Learn more about our 1650,
1680 and 1690 Series by contacting your UREI dealer today.
IBL Professional
85W Balboa Boulevard
Northridge. CA 91329
V
Circle (65) on Reply Card
www.americanradiohistory.com
TERMINAL
POLE PIECE
VOICE COIL
attached to a diaphragm and
suspended in the gap between the poles
of a permanent magnet. The clearance
between the coil and the magnet's poles
is quite small. When sound waves cause
the diaphragm to move, the coil moves
as well. By moving within the magnetic
gap, the coil induces an output
coil)
voltage-your signal.
The impedance of dynamic microphones is mostly resistive and, as a
result, the output is not substantially affected by electrical loading. These microphones are capable of a wide frequency
response and have a large dynamic
range with low noise and minimal distortion. Dynamic microphones can be readily designed to be unidirectional or omnidirectional.
Owing to their advantages and versatility, dynamic microphones are commonly used for practically every applica -
fragility and their tendency toward large
size. They do, however, provide good
frequency response (including extended
low -frequency response), excellent
sound quality and low handling sensitivity. They are used for studio recording,
broadcast and stage applications.
Basically, ribbon microphones produce
an output signal in the same way that
dynamic microphones do: a conductor
moves in a magnetic field and induces a
voltage. Instead of a voice coil, however,
a ribbon microphone has a thin strip (or
ribbon) of aluminum foil suspended between two poles of a permanent magnet.
The ribbon, which may be as thin as
0.0001 of an inch, acts like a -turn coil
and also serves as the diaphragm.
1
A basic dynamic microphone element.
tion. Size is something of a limitation,
however. Although they can be made
fairly small and lightweight, the performance of dynamic microphones tends to
suffer as they decrease in size. After all,
an effective voice coil and magnet can be
made only so small. For this reason,
condenser -type transducers have, for the
most part, taken over the lavalier
microphone market.
Ribbons
Ribbon microphones are not nearly as
common as condensers and dynamics,
largely because of their reputation for
Piezoelectrics
Piezoelectric (ceramic) transducers
have a high output and a fairly broad frequency response, especially at the lowfrequency end. They are generally inexpensive and reliable and are used in communication microphones and some
sound measurement devices. Their main
disadvantages are a high impedance
(which makes them susceptible to electrical noise) and a substantial response to
mechanical vibration.
Piezoelectric transducers have the
equivalent circuit of a capacitor in series
with a voltage generator. When mechanically stressed, the element generates a
Remote Control FREEDOM
.. .
Gentner's VRC-1000" Remote Control Unit uses
inexpensive, readily available dial -up circuits for
all types of remote control applications.
Transmitter - Main/back-up
ENG
...Dial -up Convenience!
GEIVTIVERT"
RF PRODUCTS DIVISION
Satellite
Machine Control
STL/Microwave
Broadcast Engineering
us in
Booths
426,
and 513, SBE
San Jose, California 95152
P.O. Box 32550
(408) 926-3400 Telex II: 510-600-1445
Circle (66) on Reply Card
94
Visit
September 1986
www.americanradiohistory.com
To a company whose
name means quality,
it was a natural step
to take.
Dielectric Communications is now your single source
for complete UHF RF systems due to our recent purchase of RCA's Antenna Division. Dielectric and RCA
have had a long-term association, and are both known
worldwide for highly reliable broadcasting equipment.
It was only natural for Dielectric to begin offering
these high quality antennas as part of our already extensive line of UHF components.
Over 600 UHF Pylon Antennas have been shipped
from our Gibbsboro, NJ, assembly/test range and are
providing years of trouble -free service with minimal
maintenance. These ruggedly constructed antennas
are designed for low relative windload and weight. All
use a single feed point with high power input ratings.
They are available in numerous vertical and horizontal
pattern combinations to meet a wide range of broadcast coverage requirements.
Other broadcast products manufactured by Dielectric
include: coaxial and waveguide diplexers; motorized
waveguide and coaxial switches; rigid coax and
waveguide transmission line and filter products; and
custom RF systems with Magic Tee switching for UHF
stations.
Dielectric's reliable equipment is backed by a full
range of in-house services from design to field testing.
Call us today for free specification brochures
-
1.800.341 -9678.
The
Tradition
Continues.
DIELECTRIC
r7
Raymond, Maine 04071
(207) 655-4555 (800) 341-9678
TWX: 710-229-6890
:
Circle (67) on Reply Card
www.americanradiohistory.com
,'.
I
voltage across its opposing surfaces. One
end of the piezoelectric element is attached to the center of a diaphragm
(usually made of aluminum foil) and the
other end of the element is clamped to
the microphone frame.
Controlled magnetics
Because controlled magnetic microphones have a narrow frequency range
and are highly susceptible to vibration,
they are largely unsuitable for broadcast
or stage applications. They are,
however, often used for communications
and paging, because of their fairly high
degree of sensitivity, ruggedness and
dependability.
Controlled magnetic transducers have
also been called magnetic, variablereluctance, moving-armature and balanced -armature, depending on the manufacturer. They consist of a strip of
magnetically permeable material suspended in a coil of wire, with one end
placed between the poles of a permanent
magnet. The center of the diaphragm is
attached at the suspended end of the armature.
Movement of the armature in the
magnet's gap induces a voltage in the
surrounding coil. The voltage is proportionate to the armature swing and constitutes the output signal. Electrically, the
transducer is equivalent to a voltage
generator in series with a resistor and an
inductor.
Carbons
Carbon microphones are low cost, rugged and reliable, and they have a high
output signal. They are used by the
millions in telephone handsets. However, their output is inconsistent, distorted and useful only over a limited frequency range.
The carbon microphone consists of a
metal diaphragm, a fixed backplate and
carbon granules sandwiched in between.
When sound waves move the diaphragm, they vary the pressure on the
carbon granules. The changes in
pressure in turn cause the resistance between diaphragm and backplate to vary.
The transducer doesn't actually generate
a voltage, but rather, modulates an externally supplied current.
The priorities involved in whatever job
a microphone is to perform dictates what
type of transducer element is needed.
Most broadcast applications require
either a dynamic or a condenser element. Once this has been determined,
there are other factors to consider.
Directionality
Every microphone has a directionality
or polar pattern. That is, each microphone responds in a specific way to
sounds arriving from different directions.
The polar pattern simply describes
graphically the directionality of a given
microphone. Although many different
polar patterns are possible, the most
common are omnidirectional, bidirec96
Broadcast Engineering
150
150°
90°
Izo°
t,',t dB.,
90°
30°
\
-10
5 a9
150°
Izo°41,464
g%i
,' /
I20°
lair2dwin
90"
aae
60°
°On%
180°
80°
90°
H5de
60°
60°
30°
60°
IOie
`-5A9
30°
30°
0
2,500Hz
250Hz
6,300Hz
500Hz
--- -
1,000Hz
10,000Hz
Figure
1. Typical cardioid polar pattern. The circular graph plots the output in decibels as a
function of the microphone's angle relative to the sound source.
tional and varieties of unidirectional.
An omnidirectional microphone responds uniformly to the sound arriving
from any direction, whereas a unidirectional microphone is most sensitive to
sounds arriving at the front of the
microphone. It is less sensitive to sounds
coming from other directions.
The main disadvantages of an omnidirectional microphone as compared
with a unidirectional microphone are a
susceptibility to feedback (especially in
sound -reinforcement applications) and a
lack of rejection of background sounds
and noise.
Omnidirectional microphones are,
however, widely used in broadcast applications for several reasons. It's difficult
to make a unidirectional microphone
very small. As a result, most small
lavalier microphones are omnidirectional. This doesn't create much of a
problem, however, because most broadcast situations in which lavalier
microphones are employed can be controlled to minimize background noise
and unwanted extraneous sounds.
Also, many of the microphones used
by reporters are omnidirectional,
because it's often desirable for a broad -
a
cast microphone in the field to pick up
some ambient sounds and background
noises to add to the broadcast's sense of
liveness. Another plus is the omnidirectional microphone's capability to pick up
room ambiance and natural reverberation to alleviate the aural flatness a
unidirectional mic might provide.
There are many applications, however, in which unidirectionality is a
must. The most obvious, of course, are
those that have feedback problems. By
avoiding the pickup of extraneous
sounds, a unidirectional microphone will
make
more overall
90°
150°
150°
120°lee
120°
liteoveelä
`
90°
Ire
, 0e721
*60°
60°
\\
120°
90°
90°
60°
oae
_s,,°
100Hz
500Hz
1,000Hz
Figure 2. Typical supercardioid polar pattern. Note
September 1986
www.americanradiohistory.com
150°
120°
15dB
microphone rather than at the back.
gain
180°
180°
1
system
available, resulting in less of a tendency
to set up a feedback loop. The unidirectional microphone's rejection of off -axis
sounds is often a plus in broadcast situations because the results are cleaner and
more intelligible, especially under noisy
conditions.
The most common form of unidirectional microphone is the basic cardioid
type, whose polar pattern (see Figure 1)
is graphically depicted as heart -shaped.
The area at the bottom of the heart corresponds to the on -axis front of the
microphone, the area of best receptivity.
The notch at the top of the heart cor-
30°
\
.11b
»...»
60°
_
/
30°
0
3,150Hz
10,000Hz
the nulls, which appear at the sides
of the
THE BEST SELLING STANDARDS CONVERTER WORLDWIDE
E
'
'.
Ca
1=
0
Só500
DEGITIJ STANDARDS
CONVERTER AND
PROCRSOR
AVS, manufacturers of the best selling standards converter and signal processor, introduce the AVS 6500.
The new model now includes Genlock... RGB output... SECAM linput... PAL-M option ...
Automatic input selection with manual override... Freeze-frame/Freeze-field ... Multigrab ...other processing
features of both the AVS 6000 and AVS 6500 include Switchable motion interpolation... Noise Reduction...
Horizontal and vertical chroma retiming ...Detail enhancement... NTSC comb filter decoder... Timing stabilisation.
Both models are mountable 19" rack designs with the option of a remote control panel.
AVS
Setting the Standard Worldwide
AVS, Venture House, Davis Road, Chessington, Surrey KT9 1TT. Telephone: 01-391 5678.
Telex: 267439 AVS. FAX: 01-391 5409.
AVS inc, 100 Oak Street, Norwood, New Jersey 07648 USA.
Telephone: 201 7671000. Telex: 642107.
A Member of the AVESCO plc group.
AVS users include: ABC BRITISH TELECOM CBS NEWS CENTRAL OFFICE OF INFORMATION (UK) CHANNEL 7 (Australia) CNN HELSINKI TV
QATAR TV UNIVERSITY OF THE WEST INDIES VISNEWS (UK) WORLDWIDE TELEVISION NEWS
.
Circle (132) on Reply Card
www.americanradiohistory.com
ITN MINISTRY OF INFORMATION
(Kuwait)
+10
-10
20
50
loa
10,000
1,000
20,000
FREQUENCY IN HERTZ
Figure 3. A typical frequency response for
a microphone used in stage and general sound reinforcement work. Note the high -end presence peak and low -end rolloff.
responds to the back of the microphone,
the area of least receptivity, referred to
as the null. By contrast, an omnidirec-
tional microphone's polar pattern is
ideally depicted as a circle.
Other varieties of unidirectional
microphones include the supercardioid
(in which the nulls are located at the
sides of the polar pattern, as shown in
Figure 2), the hypercardioid, and
ultradirectional types such as shotgun
microphones and parabolic reflectors.
These types offer progressively better rejection of off -axis sound but sometimes at
the expense of frequency response
and/or polar pattern smoothness.
Frequency response
The frequency response of a
microphone describes the sensitivity of a
microphone as a function of frequency
(see Figure 3). The range of the response
defines the highest and lowest frequencies the microphone can successfully
reproduce. The shape of a microphone's
response curve indicates how it responds
in this range. The specification is usually
given in hertz plus or minus some
decibel limits. In most cases, a graph
showing at least the on -axis response of
the microphone accompanies the
description.
Frequency response is often affected
cUanguand Betties"
Broadcast Audio
Consoles
by the polar pattern of the microphone.
That is, the frequency response may
vary depending on the direction of the
sound source and the distance from the
sound source to the microphone. In addition, some microphones have built-in
equalization controls that can alter their
frequency response.
What kind of frequency response a
microphone should have depends on its
application and the personal taste of the
users. There is no such thing as an ideal
frequency response for a particular
microphone. For a precise, accurate,
lifelike studio recording, a microphone
with an extremely flat frequency response might be desirable. For most
sound reinforcement and other vocal oriented applications, however, a presence boost in the upper mid-range and
rolloff on the low end adds clarity,
brilliance and intelligibility, and helps
alleviate proximity effect (the tendency
of a unidirectional microphone's bass response to increase as the sound source
gets closer to the microphone element).
When selecting a microphone for
broadcast applications, it's best to closely
examine the application and the environment in which the microphone will be
used. Will the microphone be used up
close? Consider proximity effect. What
kind of voice does the user have? A person with a low voice might prefer a high end presence boost; someone with a
Performance, Value and
Reliability through
Innovative Technology
Raised, tactile feel, lighted membrane
switch panel-digitally scanned
12 stereo inputs plus optional expander
VCA controls, rotary and linear
Analog and fluorescent meters
Modular, plug in electronics
Easy punch block installation
Effective RF protection
BC8DS
8 Mixer
Dual Stereo
only
$2,995
AUDIO
TECHNOLOGIES
INCORPORATED
328 Maple Avenue, Horsham, PA 19044
Circle (36) on Reply Card
98
Broadcast Engineering
September 1986
www.americanradiohistory.com
(215) 443-0330
frie
a4rif
hours
ten
MTBF, it could be s
With 20,000
zer
HP Audio nalyze with down
years before the won't lose p
a break. So you
And at $5800* (or
or money on repairs. you can easily afford
a source),
$3900* without audio distortion analyzer
reliable
the most
on the market.
the HP8903B/E, call es, or
For details about listed in8the white
123
your local HP office
1-800-55
number.
free
toll
41 26-12 ext.515.
use our
California,
ext.515.In
L1-800 HEWLETT
eaPACKABO
"U.S. list price
Circle (68) on Reply Card
www.americanradiohistory.com
high-pitched voice might prefer a flat
response. Will the microphone be worn
on the chest? Some microphones' frequency responses are specially tailored
to compensate for chest resonance. Also,
think about the kind of room or
enclosure in which the microphone will
be used.
There are a lot of variables to consider,
but in the final analysis, the best judge of
the right microphone is a trained ear.
Other considerations
Other microphone specifications that
should be considered when selecting a
particular model for a particular job include sensitivity (the voltage or power
output level of a microphone as a function of the sound -pressure level applied),
impedance rating (which tells the user
whether the microphone is compatible
with other equipment), polarity and
power requirements.
Microphone specifications that may be
critical to a broadcast application include
hum and RFI pickup, output noise, clipping level, maximum sound-pressure
level (SPL) and signal-to-noise (S/N). The
hum pickup (or hum sensitivity)
describes the microphone's susceptibility
to stray electromagnetic fields from
power
transformers and other ac sources. The
measurement usually is given in
equivalent SPL for a specified hum field
fluorescent lights, motors,
strength.
The RFI sensitivity
of
a
microphone, although not usually
specified, is a measurement of the
susceptibility of the unit to radio frequency interference. In general, condenser
microphones are more at risk than
dynamics, but any application in an area
of strong radio or TV signals requires
minimum RFI sensitivity.
The output noise of a dynamic
microphone is a function of its actual impedance, because a dynamic micro
phone is a passive (non -powered) device.
In practice, the noise figure for a
dynamic microphone is never quoted.
For condenser microphones, however,
the output noise is an important and
measurable quantity. Because the condenser microphone is an active device,
its internal circuitry produces a finite
amount of electrical noise. This measurement usually is given in equivalent SPL
with a specified weighting curve that
relates the noise to its perceived
loudness by the human ear. The lower
the noise figure, the better.
The output clipping level of a
microphone is its maximum electrical
output (in volts or decibels) before significant distortion is produced. It is usually
given at some specified load impedance(s) together with the minimum
recommended load impedance. Again,
this figure is quoted only for condenser
microphones, because it is a function of
the active circuitry in the device. The
maximum output level of a microphone
is affected by the input impedance of the
associated equipment.
Maximum SPL (given in decibels at
one or more load impedances) refers to
the loudest sound the microphone can
take before distortion occurs. Once
again, this is always specified for condenser microphones and almost never
for dynamics. The limitations in the condenser microphones are the internal circuits and, in some cases, the condenser
element itself. Dynamic microphones
have no active internal circuitry to
overload, and dynamic elements are
generally capable of withstanding much
higher sound-pressure levels without
damage or distortion.
The microphone's S/N is the difference
(in decibels) between the residual output
noise of the microphone and the output
level of the microphone at some
specified input SPL (usually 94dB). This
specification applies only to condenser
microphones because of their inherent
output noise and maximum output level
limitations.
It's obvious that a lot of variables are
involved in the microphone's task of
changing acoustical energy to electrical
energy. Fortunately, the variety of
microphones available is so vast that you
can find a suitable one for just about any
application.
I: )))I
-
IT'S IN THERE SOMEWHERE.
you just need time to find it.
Time code. As a video professional, you know the vital role
it plays in the editing and tape management process.
DATUM's 5300 ITP
Our Intelligent Time Processor (ITP) can give you all
the time code capability you'll ever want. It's
available in four models, ranging from a basic
SMPTE/EBU time code reader/generator
to a comprehensive processor, complete with character generation and
VITC code capability. And it's
expandable. You can choose the
basic unit now and upgrade later.
Let us show you what our 5300 ITP can
do for you.
Call or write for complete information.
Datuminc TIMING DIVISION
1363 S. State College Blvd.
Anaheim, CA 92806
(714) 533-6333
Circle (63) on Reply Card
100
Broadcast Engineering
September 1986
www.americanradiohistory.com
44.
III
he Ones to Watch!
IKEGAVI'S BROADCAST & INDUSTRIAL VONITORS:
WE HAVE WHAT YOU'RE LOOKING FOR.
Whether you re looking for broadcast or
industrial color or B&W monitors, one look at
an Ikegami 9. 10. or 3H series monitor and
you II look -o more.
And now everyone can afford to own an
Ikegami monitor with prices starting at under
$400 for cur new PM9-5. 9" monochrome
model.
Ikegami 's
9
series high resolution
broadcast Television monitors utilize In -Line
Gun self converging cathode ray tubes with
American Standard matched phosphors and
are availab e in a 20. 14 and 10 inch models.
The 1C series resolution broadcast television moritors utilize Delta -Gun tubes to
achieve maximum brightness and exceptional convergence and are available in 20
and 14 inch versions.
The 3H series high resolution broadcast
television monitors feature high quality
monochrome displays suitable for sophisticated broadcast studio applications. Available in 9, V, single and dual 9 inch monitors.
For a complete demonstration of
Ikegami monitors and cameras, contact us
or visit your local Ikegami dealer.
Prices Stare At Under $400
kegami
Ikegami Electronics (USA), Inc. 37 Brook Avenue Maywood, NJ 07607
East Coast: (201) 368-9171 West Coast: (213) 534-0050 Southeast: (813) 884-2046 Southwest: (214) 233-2844 Midwest: (312) 834-9774
Circle (70) on Reply Card
www.americanradiohistory.com
Classic beauty is unmistakable. You know it when you
see it.
Like the beauty you get
w th Ampex 196. Clean, clear
pictures that capture every
sparkling moment of your
production.
No other video tape
delivers such consistent low dropout performance. Or such
dynamic picture quality.
By focusing on critical drop o its, especially in the area
not compensated for by your
VTR, we developed a video
tape you can rely on for all
your applications.
The secret behind our
success is Ampex Process
Management. APM is a unique
manufacturing concept
elabling us to control the
consistency of the entire production process. From raw
materials to finished products.
So you always get the
c eanest, sharpest pictures time
cfter time, reel after reel,
carton after carton. That's why
top professionals around the
world specify Ampex 196.
If you'd like to know more
about how APM contributes
h beautiful pictures, call or
write Ampex today for a
free brochure.
Ampex Corporation, Magnetic Tape Division, 401 Broadway, Redwood City, CA 94c63, 41/367-3804.
www.americanradiohistory.com
AU
T
',`
/WIPE
Circle (71) on Reply Caro
www.americanradiohistory.com
Planning wireless
microphone systems
By H.Y. Miyahira
and Donald A. Kutz
Wireless microphones are useful devices, but you have to
do a lot of planning in order to avoid trouble.
Technological advances of the late
1960s have tremendously affected both
the size and performance of wireless
mics. Until the mid -60s, wireless mics
were large and used miniature vacuum
tubes, offering limited dynamic range
and poor audio quality. The advent of
semiconductor technology in the late
1960s eliminated many problems.
In the early 1970s, the integrated circuit compandor was introduced and was
incorporated into the wireless mic. At
about the same time, the FCC authorized
the use of frequencies in TV channels 7
through 13 for wireless mic use. Thus,
the wireless mic's most serious problem-radio interference from other
services-was virtually eliminated.
Diversity reception was developed,
which minimized dropout and greatly
improved transmission reliability.
Today's wireless microphones provide
quality and reliable operation. They are
small, lightweight and rugged. (See
Figure 1.) Even so, wireless mics are
prone to pitfalls, most of which can be
eliminated by careful planning.
Radio frequencies
There are no international standards
i
AUDIO
INPUT
I
I
\
for wireless mic radio frequency allocations or performance standards, such as
transmitter power limits, frequency
stability or RF bandwidth. The frequency
bands typically used for wireless microphone systems are shown in Figure 2.
The FCC regulates the operation of
wireless mics in the United States, under
the following rules (see Figure 3):
Part 15, Subpart D, allows low -power
communication devices to operate in the
49.81MHz to 49.90MHz band. Power is
limited to 10,000µV/m (approximately
1mW to 5mW) radiation at a 3-meter
distance and a 5kHz audio frequency
limit. This RF spectrum segment is
susceptible to high levels of manmade
noise. This noise is typically generated
by auto ignition, fluorescent lights and
dimmers. The band's low -power restriction imposed by the FCC only aggravates
the problem. Also, because these frequencies are evenly spaced 15kHz apart,
only three wireless mics can operate
simultaneously without RF intermodulation products causing interference.
Part 15, Subpart E, allows wireless
mics to operate in the commercial FM
broadcasting band with only 50µV/m
radiation at 15m. With this power restriction, it is not practical to use this band for
professional applications in which
reliable transmission performance is
needed.
Part 90 allows wireless mics to operate
on a shared basis with business radio
services. Continuous radio transmission
authorized if the transmitter power is
limited to 120mW. This is a significant
improvement over the limitations of Part
15. The business radio service frequencies for wireless mics are: 30.76MHz to
is
FUNCTIONS AS WIRES
Figure I. Block diagram of
a
wireless
microphone.
Miyahira is president of HM Electronics, San Diego.
Kutz Is vice president of operations for HM Electronics.
Figure 2. International
frequency allocation
for wireless microphone systems.
43MHz (VHF lowband), 150MHz to
173.4MHz (VHF highband), 457MHz to
470MHz (UHF lowband) and 806MHz to
866MHz (UHF highband).
More recently, the FCC authorized the
use of frequencies between 169MHz and
171MHz on a shared basis with other
non-government and government operations, but with less susceptibility of interference. These frequencies were
formerly reserved for hydrological or
meteorological data transmissions.
At 150MHz and higher, manmade
noise decreases significantly. With the
higher power, greater transmission
bandwidth, many more available frequencies and the shorter antenna requirements, operation in the VHF highband (and higher) is more desirable than
operation at lower frequencies. The major disadvantage with operation under
Part 90 is interference from other
business radio services, except for the
limited frequencies formerly assigned to
hydrological services. Station operating
licenses are required and the transmitter
must be FCC type accepted.
Part 74 restricts wireless mic use to
broadcast, video production and filmmaking applications. Wireless mics can
operate in the 174MHz to 216MHz range
(TV channels 7 through 13) on a noninterference basis. This means that, for a
given location, wireless mics can operate
on unused TV channels. Transmitter
power is limited to 50mW. Station
operating licenses are required for
broadcasters and filmmakers, and the
transmitter must be FCC type accepted.
VHF highband operation under Part 74
offers the best operating area for
wireless mics.
RF frequency characteristics
The free -space transmission loss between a transmitter and a receiver with
J
MHz
104
30
50
70
Broadcast Engineering
80
88
108
120
210
September 1986
www.americanradiohistory.com
400
410
450
470
940
960
Did you know. .. that with
a UHF TV transmitter from
Philips you pay for
a lot less?
... a lot less
space to house it
.... a lot less attention
to keep it maintained
... and a lot less money to run it
Every business wants to keep its costs down.
So it's hardly surprising that so many people
have already chosen our UHF television
klystron tubes
for outputs
between 30 and
transmitters.
240kW. You'll
soon see the
value of getting
a lot less for
your money.
There are plenty of reasons: the tremendous
quality of our equipment, their compact size,
the design concept with everything built-in,
easy maintenance, easy adjustment, high
efficiency and excellent stability.
The result for you is substantial savings
on the cost of housing the transmitter, of
maintaining it and of running it. The result
for us is that we're now the largest off-shore
supplier in America - and have well over
2000 installations world wide.
See the UHF 1790 range with high power
PHILIPS TELEVISION SYSTEMS, INC.
900 Corporate Drive, PO Box 618, Mahwah,
New Jersey 07430 USA Tel: 201-529-1550
Telex: 37-62558
Canada: Electro & Optical Systems Ltd, 31 Progress
Court, Scarborough, Ontario, Canada M1G 3V5
Tel:
(416) 439-9333
Telex: 065-25431
Philips UHF television transmitters
PHILIPS
Broadcast Equipment
PHILIPS
Circle (89) on Reply Card
Reliability thr(niTh Quality
www.americanradiohistory.com
FCC
RULES
PART 90
®
e
PART 74
riving at the receiver via various paths.
The loss of reception at the wireless
mic receiver is usually referred to as a
dropout. This dropout is caused by
several factors. if a transmitter is, for example, too far from the receiver, increasing P, can help, but battery consumption
and FCC regulations must be considered.
The
can be increased, but physical
limitations and cost must be weighed.
Most dropouts are caused by multipath
cancellations. Multipath occurs when the
transmitted signal takes more than one
path to the receiver. Several paths can
occur when the environment in which
the wireless microphone is operating
contains metal or objects that reflect
radio signals. In TV studios, multipath
can be caused by cameras, lighting
equipment or scenery. Due to the arriving signal's phase differentials, the resultant signal can be enhanced or totally
A
PART 15
PART 15
D
1
I
FREQUENCY
100MHz
I
I
200MHz
S00MHz
400MHz
500MHz
55
I
I
800MHz
900MHz
Figure 3. Wireless microphone frequency bands for the United States.
an isotropic antenna can be computed by
the following equation:
« = -37.85
Where:
+ 20 log F
+ 20 log D
= space transmission loss in
decibels
F = frequency in megahertz
D = distance in feet
«
This equation clearly shows that less
transmitter power is required for an
equivalent signal strength at the receiver
as the frequency is lowered. A major difficulty for wireless microphone manufacturers is the design of efficient antennas
for lowband VHF operation. However, at
highband VHF, efficient radiators are
quite practical. Consequently, the
150MHz to 216MHz band is usually more
desirable than the UHF band.
Manmade noise decreases with increasing frequency, becoming asymptotic to galactic noise near 400MHz.
Above 150MHz, manmade noise is not a
serious problem for most applications.
Interference from other radio services
is the major problem at both VHF and
UHF. The only clear channels available
are the unused local TV channels. For
remote applications, this becomes a
problem because a clear TV channel in
one city may not be clear in another.
Traveling groups, therefore, use the
former hydrological frequencies as the
best alternative.
This relationship is important to
understanding the practical solutions and
limitations that must be considered in
any FM wireless mic system. Not all of
the power (P,) transmitted will reach the
receiver. Transmission efficiency is also
degraded by path losses from interfering
objects (such as people and other equipment) between the transmitter and
receiver, the transmitter antenna
polarization and interfering signals from
multipath reflections. These three
elements affect the total power P, received at the antenna A,, The total
algebraic sum of these signals must be
considered and the power at the receiver
.
now becomes:
P, =
P,
A
+
P,
E
multipath
dropouts. One technique that is useful in
minimizing multipath dropouts is true
diversity reception.
True diversity reception
True diversity reception requires two
or more receiving antenna systems. The
conditions required to take advantage of
diversity reception include:
a single transmitter source,
uncorrelated, statistically independent
signals and
multiple receiving antenna systems.
The success of any true diversity
reception system depends on the degree
to which the independently received
signals are uncorrelated. If a true diversity reception system cannot produce un-
n
4aD;
canceled, thus creating
Luk
k=1
correlated, statistically independent
Where: n= number of paths considered
Lk = amplitude of the Km
signal
e k = phase of the K'5 signal
Note that the second term on the right
side of the equation could be net positive
or negative, depending on the relative
amplitudes and phases of the signals ar-
signals, then a diversity reception system
does not exist. The block diagram of a
basic true diversity reception system is
shown in Figure 4.
A single transmitter generates signals
over paths D,,, and D,,,, that arrive at the
diversity receiver for processing. A true
diversity reception system can be implemented in many ways, but all systems
Continued on page 110
REFLECTIVE SURFACE
Dropouts
A wireless mic transmitter radiates
power in many directions simultaneously. The exact pattern depends on the
UNCORRELATED INDEPENDENT SIGNALS
specific mechanical configuration of the
antenna system. The power (P,) received at the receiver antenna is:
P, A,o
P, =
4
r
PATH
TRANSMITTER
SOURCE
D2
N
ANT
1
ANT
MULTIPLE
RECEIVING
ANTENNA
SYSTEMS
Where: P, = Power transmitter
= Area of receiver
A
antenna
D,, = Distance from
transmitter to
receiver
106
Broadcast Engineering
Figure 4. Simplified block diagram of a true
diversify reception system.
September 1986
www.americanradiohistory.com
COMBINING/SWITCHING
CIRCUITS
K
It takes a unique graphics look
to stand out from today's look alike news productions. So
we've built some unique graphics
tools into our new ESS-3 Still Store
that you won't find anywhere else.
The ESS-3 lets you compose an
unlimited number of elements, all
with the fidelity of first generation
video. You can cut and paste, key
and drop shadow irregular shapes,
and program your own dissolves,
cuts and wipes. And with its var-
iable compression you can insert
over -the -shoulder stills-without
a digital video effects unit.
If you're bored with your titles
simply scan in your own typefaces;
then resize, compress, color and
dropshadow to achieve your own
new look.
And, to make your news preparation fast and effortless, the ESS-3
displays 12 stills at one time for you
to browse through and edit. Compare that to any description -only
www.americanradiohistory.com
index system.
So if you want to jazz up your
news, and get the signal quality that
comes only from Ampex, get the
complete story on the new ESS-3.
Atlanta (404) 491-7112 Chicago (312) 593-6000
Dallas (214) 960-1162 Los Angeles (818) 365-8627
New Jersey (201) 825-9600
(In New York (212) 947-8633(
San Francisco (415) 367-2296
Washington, D.C. (301) 530-8800
Canada (416) 821-8840
AM PEX
Ampex Corporation
One of The Signal Companies
NOW, A LINCH
VIDEO TAPE THAT
LOOKS GREAT TO
Introducing -inch
EASTMAN Professional
Video Tape, EVT-2000 (Broadcast
Quality). With the
durability to satisfy
the toughest editor,
and the signal characteristics to
brighten the eyes of the most
demanding engineer.
The latest advances in binder technology have produced a highly
durable video tape that runs
smoothly and withstands the
ravages of heavy editing and
still -framing without increasing
EDITORS
1
ND ENGINEER
headwear.
New EASTMAN Professional
Video Tape, EVT-2000, is formu
lated to deliver clean, crisp,
brilliant pictures and excellent
audio performance. Chrominance and luminance are
superior. Dropouts are minimal.
EVT-2000 is recommended for
production, post production, and
heavy editing, while our economical EVT-1000 video tape is suggested
for duplicating and syndication.
EASTMAN Professional Video
Tape, EVT-2000, is available in C format lengths from 34 to 188 minutes
and B -format lengths from 34 to 126
minutes.
For details, write to Eastman Kodak
Company, Dept A3067, 343 State
Street, Rochester, NY 14650. Or call
toll free 800 44KODAK (1 800 445-6325),
Ext 864.
1
EVT-2000
PROFESSIONAL VIDEO TAPE (BROADCAST QUALITY)
www.americanradiohistory.com
EASTMAN EODAh 7.:OMPANY, Motion Picture and
Audiovisual Products Division.
Video Graphic Courtesy of:
Abel Image Research/Cinecommunications, Malaysia/
KHK/Needham, Malaysia
Eastman Kodak Company, 1986
C
rcle (74) on Rep
y
Cad
www.americanradiohistory.com
Continued from page 106
combine the received
independent
signals in some method. The particular
combining technique chosen is based on
cost and the degree of improvement required. The less predictable or less closely related the signals over paths D,r, to
D, , the more significant the benefits
provided by the diversity system.
Diversity classifications
True diversity reception techniques
are classified by the method of processing and extracting the uncorrelated
statistically independent signals. Common classifications for true diversity
systems are outlined in Table 1.
The technique most commonly used
for wireless microphones is space diversity. Space diversity can be implemented
in many different ways, but the three
basic requirements of diversity reception
mentioned earlier must still be satisfied.
Polarization diversity is a special case
COMBINING METHOD
TECHNIQUE
SELECTION (ALSO REFERRED
TO AS SWITCHING OR
OPTIMAL SWITCHING)
SWITCHES TO OPTIMUM INPUT
MAXIMAL RATIO (ALSO
REFERRED TO AS VARIABLE
GAIN)
ADDS SIGNALS WITH VARIABLE
GAIN AMPLIFIERS
EQUAL GAIN (ALSO REFERRED
TO AS LINEAR ADDER)
ADDS SIGNALS LINEARLY
Table 2. Combining methods for processing signals of a diversity receiving system.
of space diversity. Here, the receiving
antennas must be orthogonally located
in order to capture the uncorrelated independent signals.
For space diversity systems, two or
more receiving antennas are required
and they must be located at least
1/2 -wavelength
apart. The amount of
separation determines the degree of the
DIVERSITY
RECEPTION
TRUE DIVERSITY
CLASSIFICATION
TECHNIQUE
SPACE
X
SPATIALLY SEPARATED
ANTENNA
POLARIZATION
X
ORTHOGONAL ANTENNAS
(
Table
1. Classifications
of true diversity receiving systems.
uncorrelated signals. Each antenna in
the array provides an independent path
that is combined to produce the desired
signal improvement.
Combining methods
The various combining methods for
processing the independent signals are
shown in Table 2. Selection combining
results in switching to the incoming
signal with the best signal-to-noise ratio.
Figure 5 depicts a selection diversity
combiner that can be used either before
or after audio detection.
In maximal ratio combining, the input
signals are weighted proportionately to
their carrier S/N power ratios and then
summed. The input signals must,
therefore, be co-phased. A modification
of this approach is equal gain combining,
By replacing conventional gears which control the zoom and focus servos with modern ny b
Angenieux has made yet another breakthrough in the design and construction of its broadcast lenses.
Substantially lighter, mechanically quicker, and dramatically quieter, with sophisticated internal hood
soundproofing, recessed hood handles, an internal heater, digital readouts for iris position, extender
position, and a three lamp diascope all standard, Angenieux's New Generation of broadcast lenses are
at the crest of the industry's future wave.
Among Angenieux's New Generation of ENG zoom lenses are the 14x7 ultra wide angle, the 14x8 with
a non -rotating front focusing element, and the 14x9, all with a maximum relative aperture of f/1.6the fastest in the industry.
For studio and outside broadcast use Angenieux's New Generation includes the new 15x HP series
15x13 HP 1 format and 15x17 HP 11/4' format-and the high quality studio/O.B. 18x12.5 1" format
and 18x16.5 1 1/4" format lenses.
And that's not all. Angenieux's highly skilled engineers are working harder than ever before to meet
the industry's demand for more and better broadcast lenses.
ANGENIEUX. The New Generation. The Heritage Of Excellence.
-
angenieux
Opticam SA,
4.
Corp. of America 7700 No. Kendall Dr., Miami, FL 33156
Rue Pedro Meylan, Case postale 91, 1211 -Geneva -17, Switzerland
Circle (49) on Reply Card
110
Broadcast Engineering
Tel: (305) 595-1144
Tel: 22-36-22-66
September 1986
www.americanradiohistory.com
Telex: 80-8425
Telex: 27670 Optic CH
FAX: 305-595-4636
FAX: 22-86-12-49
Ov r Smart Little Switch Now Has The Self:
T
R
O
L
N
CO
Of A Yoga Enthusiast
In 1979, our "Smart Little Switch" led the industry. At the time, this 10 x 10 switch had things pretty
well under control. With its HDTV performance and component capability at NTSC prices, it soon
had risen to become our fastest selling product. Today, it's still the source of considerable peace of
Now we've teamed the Smart Little Switch with our new Series 1
mind on the part of users.
Controls and are achieving far greater levels of self-control. With a wide range of options,
Just connect our PCA -904A
users can add big system features to any Series 10 ever built.
Control containing one of its many software programs to the comm line and you have
in one rack unit. Insert a different program and
X -Y control of the entire matrix
you have sequential control that even remembers what you do for the time you
do it. That's not all. Select from our growing library of software programs,
in combination with Series Controls, and you can achieve such big system
features as: Batch switching from a VDT or computer, or simply from 20
push buttons, each programmed for a different batch Dedicated two bus control in a single rack unit Long distance computer control via
modems. How's that for control? Using our new Series 1 Controls,
there's no end to the system well-being that can be achieved if you
put your mind to it. Why not Lotus Position your Series 10 for
higher levels of control. If you're not a Series 10 user, with a
little serious meditation you could be. To order, control
yourself and call: 800-854-2831 NA. 619-263-7711 CA.
-
1
Leaders in Signal
(D
Switching and Control
See us at SMPTE
Booth No. 1309
ALI 1=1.
5275 Market Street, San Diego, Califorcita92114
Circle (75) on Reply Card
www.americanradiohistory.com
i
v
RECEIVER PRE.DETECTION
INPUT
RECEIVER PRE -DETECTION
INPUT
(OR POST.DETECTION OUTPUT)
(OR POST -DETECTION OUTPUT)
in which all inputs are set equal to a constant unity value. A comparison of the
combining methods and relative improvements are shown in Figure 6.
Figure 7 is a block diagram for a system
that allows either maximal ratio or equal
gain combining.
10
l
GAIN SET
AND
SUMMING AMPLIFIERS
o
8
PP
tSP+\t5
OJP OP\P
E
6
V
SIGNAL OUTPUT
Figure 5. Block diagram of a selection diversity system.
AgE1.ECt10H
4
2
The CDI-750 Time Code
Reader/Generator
s
ó
2
3
4
5
6
7
8
9
10
NUMBER OF INPUT SIGNALS
Figure 6. Comparison of
the predicted S/N
improvement for three combining methods.
Clearly, the maximal ratio combining
method offers the best possibility for improvement over a non -diversity system.
Unfortunately, it is also the most difficult
to implement. Wireless mics typically use
selection and equal gain combining
diversity. The choice is based on reducing the probability of dropouts. Any of
the combining techniques can be implemented in the receiver in pre- or postdetection. A comparison of the advantages and disadvantages of various combining methods is shown in Table 3.
Compandors
More
than just
a matter
of time
The CDI-750 is a full function reader, generator, character inserter and programmable 16-event controller
all rolled into one. In addition to simultaneously
generating and reading time code, this intelligent
microprocessor-based instrument offers a programmable jam sync mode, built-in time of day clock, and
an RS -232/422 computer interface. And with front
panel controls, the CDI-750 is an easy unit to operate,
affording the user greater flexibility.
Fully compatible with the Shadow II" and Softouch,"
this system's state-of-the-art software controls make
it readily adaptable to future needs.
Each unit carries a 3 year warranty.
For more details contact Cipher Digital today. Call
(800) 331-9066.
cipher cigital, inc,
P
O BOX 170/FREDERICK. MD 21701
(301)695-0200
70KP.29
today,
TELEX
272065
rOhS'lStPrl+tGltXt
tO1++C)UIoAI.
Circle (78) on Reply Card
112
Broadcast Engineering
September 1986
www.americanradiohistory.com
The audio compandor developed from
the telephone industry's need to improve
long-distance cable communications.
First used in the New York/London radio
circuit in 1932, the compandor provided
a great improvement in signal quality
and helped overcome the problems of
static and limited dynamic range. The
Bell System first used compandors on a
wire line in 1941, further improving
telephone transmission quality.
A compandor is a 2 -part system consisting of a compressor that reduces the
audio range by providing more gain to
weak signals, and an expander that
restores the signal back to its original
dynamic range ratio. The degree to
which the audio energy is compressed
and expanded is referred to as the compression ratio. Wireless mics typically
use a 2:1 compression ratio. Figure 8
shows how various audio signal levels
might be processed by a compandor with
a 2:1 compression ratio.
Audio compandors are available with
variable gain amplifiers that respond to
changing input levels. With these
devices, a dynamic range of 100dB or
more can be achieved. Without a cornpandor, a wireless mic is subject to noise
FROM HAIRPIN TURNS
TO
ON
SPEED
NEVER
BEEN SO
OTIL
For years, sloppy tape transportation and handling
have made the audio engineer's day much harder than
it had to be.
This tormenting state has come to an end with the
introduction of Sony's APR-5000 2 -track analog recorder, available in a center -track time code version.
The APR -5000's precise handling and numerous
advanced features make the audio engineer's day run
much smoother. For example, the APR -5000's 16 -bit
microprocessor manages audio alignment with a precision that's humanly impossible. And the additional
8 -bit microprocessor opens the way for extremely
sophisticated serial communications. In tandem, they
reach a truly unique level of intelligence.
Not only does the APR-5000 do its job well; it does
it consistently. The die-cast deck plate and Sony's longstanding commitment to quality control maintain that
the APR-5000 will hardly need time off.
All of which results in a consistent sonic performance that'll stand even the most critical audio professionals on their ears.
For a demonstration of the re-
corder that transports analog audio
to a new fidelity high, contact your
nearest Sony office:
Eastern Region (201) 368-5185;
4110>
Southern Region (615) 883-8140;
Central Region (312) 773-6000;
Western Region (213) 639-5370;
Headquarters (201) 930-6145.
SONY
Professional Audio
©
1985 Sony
Corp. of America. Sony is a registered trademark teSon=
Circle (79) on Reply Card
www.americanradiohistory.com
t
p.
ANT
TANT
1
RECEIVER PRE -DETECTION
INPUT
(OR POST-DETECTION OUTPUT)
K
RECEIVER PRE -DETECTION
INPUT
(OR POST -DETECTION OUTPUT)
SELECTION BASED
ON BEST SIN
those for FM) are used to further improve
the transmitted signal. The combinations
of pre-emphasis and companding usually
result in a better-performing system.
Some wireless mic systems use a
limiter to prevent distorted signals.
Although this approach may be useful, it
is seldom sufficient for professional applications. With this design, the limiter
limits the peak input signal without
distortion from 30dB to 40dB. This
means a source with 100dB dynamic
range can be transmitted over the radio
system with 60dB, undistorted. Obviously, 40dB of dynamic range is lost.
-
SELECTOR
OUTPUT
Figure 7. Block diagram of a maximal
ratio/equal gain wireless microphone system.
from its transmission medium and the
audio is seldom acceptable for most professional applications.
Compandor systems are subject to
phenomena known as breathing and
pumping. Breathing occurs with the
release of gain adjustment as it returns to
normal. Pumping is associated with the
attack on the gain. Both occur when the
expansion circuit mistracks the compression circuit. The result is signal expansion that is either greater than or less
than the original compression along with
unmatched time constants.
Pre -emphasis networks (similar t'
COMBINER
ADVANTAGES
DISADVANTAGES
SELECTION
NO
SWITCHING TRANSIENTS
CO -PHASING
REQUIRED
POSSIBLE
HIGH COST WHEN
IMPLEMENTED IN POST DETECTION
MAXIMAL
RATIO
BEST IMPROVEMENT
EQUAL GAIN
IMPROVEMENT IN
COST AND COMPLEXITY
IN S/N
CO -PHASING
REQUIRED
FOR OPTIMUM
S/N
PERFORMANCE
LOW
COST
Table 3. Comparison of advantages and disadvantages of combiner methods.
Advancing technologies can move at
such a rate a new product may blur
by without offering the true explanation of why it was developed in the
first place.
Quite simply the new GLM is a
superior studio quality microphone
that incorporates all the benefits
of its larger more conventional
predecessors.
Crown technology has always
ignored the conventions of new
product development and recognized
no limits in achieving the ultimate
in professional quality.
See your nearest Crown dealer. Find
out how this incredibly small microphone achieves such a high level
of performance.
Crown International, Inc., (219) 294-8000
1718 W. Mishawaka Rd., Elkhart, IN 46517
ocrown,.
Circle (80) on Rep
114
Broadcast Engineering
Card
September 1986
www.americanradiohistory.com
THOMSON rJ
TTV 1623/1624:
the choice
o` two camera heads and seven
adaptors gives a range of
lightweight and high performance
cameras to cover any event.
SCOOP CATCHER
The color video cameras TTV 1623/1624
make available a new generation of
lightweight cameras. With 3 basic
camera heads, 7 adaptors and the
Betacam® VTR, they make up a
complete family, covering a wide range
of requirements, from news gathering to
studio productions.
Integral VTR, auto -setup, comprehensive
remote control, scene files: a level of
THOMSON VIDEO EQUIPEMENT
possibilities and configurations never
seen before. The best of Thomson's
Because the best need the best
technology and quality; the know-how
of a world leader
in
advanced electronic
FRANCE (HEAD OFFICE)
U.S.A.
equipment.
THOMSON VIDÉO ÉQUIPEMENT
17, rue du Petit Albi - CERGY-SAINT-CHRISTOPHE
THOMSON-CSF BROADCAST Inc.
37 Brownhouse Road - STAMFORD
Betocam® is a registered trade mark of Sony
BP
8244 - 95801 CERGY-PONTOISE CEDEX
Phone (1) 34.20.70.00 - Telex 204.780 F
Fox (1) 34.20.70.47
CT 06902 - U.S.A.
Phone (1203) 965.7000
Fax (1203) 327.6175.
Circle (81) on Reply Card
www.americanradiohistory.com
-
Telex 6819035 TCS FB.
-
INPUT
LEVEL
.20dB
COMPRESSION
EXPANSION
0dB
SIGNAL
IN
-
BOdB
I
i
NOISE
80dB
\
Figure 8. Gain level chart for
-
OUTPUT
LEVEL
--
SIGNAL F.
20dB
NON-LINEAR
DEVICE
0dB
SIGNAL
OUT
SIGNAL
OUTPUT
F2
00dB
-80dB
a 2:1 audio
companding system.
FREQUENCY
Multiple microphone systems
IM5
When using multiple wireless mics,
consider the interference from other
sources. These sources can include:
IM3
F1
IM3
F2
IM5
Figure 9. Intermodulation
is produced when
two or more signals combine in a non-linear
device.
transmitter spurs,
transmitter and receiver intermodulation and
splatter.
The FCC requires that all wireless
microphone transmitters conform to the
following limitation:
Maximum spurs (dB) =
-43dB
-
10
log
P,
1W
Although an individual
transmitter
should conform to these specs, its
performance may not be adequate when
six to eight wireless microphones are
operating together. Spurious signals are
generated within the transmitter by mixing together the various signals created
in multiplying the crystal oscillator frequency up to the carrier frequency.
These mixing products, if they fall within
the bandwidth of the receiver, will be
heard as birdies or squeals. These
spurious transmitter outputs are discrete
spectral signals and usually cannot be
easily removed. The higher the multiplication factor used to generate the carrier, the more numerous the spurs can
become.
Intermodulation
T5010. The SMPTE Time Code Generator/Reader
Legends are made to face
the test of time. The T5010
is no exception. Our most
versatile Time Code Reader/
Character Generator, the
T5010 leads the industry with
its user oriented features.
Discover a legend in time.
Contact your local Telcom
dealer, or call us for details.
We'd like to share our time
with you.
The Telcom T5010.
talcum earl>
research
1163 King Road,
Burlington, Ontario. L7R 3X5 (416)681-2450
Circle (116) on Reply Card
116
Broadcast Engineering
September 1986
www.americanradiohistory.com
Transmitter intermodulation, or 1M,
can occur when a carrier frequency from
one source is coupled into the output
stage of another transmitter. These two
signals may combine in various ways,
creating additional RF signals. Typically,
if the output transistor operates non linearly, the two signals can create a
series of mixing products as shown in
Figure 9.
The transmitted IM products may overload the receiver. If the receiver can't
eliminate the interfering signals, the
result may be the creation of squeals,
birdies and an overall sensitivity degradation. These IM products can also be
generated in the front end of the
receiver. This may occur if the local
oscillator signal leaks into the antenna.
When operating multiple wireless microphones, you can help identify the po-
Stations
looking to automate,
look to IGM.
r..,j_.,,1rrrffffit>
.,;:;_..,-
=
Weft Nefflikeiliff
When you are thinking of using a program automation
system, a number of questions come to mind. How
do handle network news? How many events of
memory do need to handle any format? How will this
work with my billing system? With over 20 years of
experience, IGM can help you determine how best to
add automation to your operation. The broadcast
industry has counted on IGM to build automation
systems for all kinds of operations, from small radio
stations to network operations.
We can build a program automation system for your
station using an IBM-PC or compatible as the brain to
I
I
///
control the IGM -SC or IGM -EC automation controllers.
Depending on your specific application, you can add
the IGM GoCart and Instacart to handle your
commercials and announcements or, if you need
reel-to-reel machines or other cart machines, we can
include the Studer-Revox PR -99 and Fidelipac cart
machines in your system.
For information on how you can use automation
successfully, call
800-628-2828
Ext.
578
IGM COV V \CATO\S
282 West Kellogg Road
Bellingham, Washington 98226
Circle (83) on Reply Card
www.americanradiohistory.com
(206) 733-4567
FREQUENCY (IN MEGAHERTZ)
sion range. However, other parameters
more critical to performance and reliability should be examined carefully.
The following tests may prove useful
as you evaluate different wireless
microphone systems:
06
180.8
181.4
184.0
2.8
2.0
0.8
183.4
J
A sample calculation of IM compatibility for an event using four wireless
microphones.
Figure 10.
A-B test
Using a wired mic with an element or
model number identical to your wireless
mic's, feed both mic outputs into an A-B
switch. If an A-B switch is not available,
feed both mics into a mixer. Now test for:
Frequency response. Both mics
should sound identical, with one not
brighter or duller than the other. The
wireless mic should not sound better, but
the same as the wired mic.
Gain. Output levels should be nearly
identical.
Phase. With both mics placed near
each other, a properly phased wireless
mic will not show any cancellation.
Dynamic range. Shout into the mic.
Listen for distortion at high levels. Note
any pumping and breathing action or
other compandor characteristics.
Noise floor. With the mixer gain for
each mic set about equal, listen for
overall noise floor differences.
tential for IM through a simple calculation. First, list all the mic channel frequencies. Then calculate the differences
between the carrier frequencies. If any
two differences are the same or within
0.1MHz, IM may become a problem.
Figure 10 illustrates this process. The
four frequencies are not compatible because there is a difference of only 0.6
and 2.6, respectively. Spurious signals, IF
offsets and any known discrete frequencies in the environment also should be
considered. A simple computer program
lets you make the calculation quickly
and accurately.
Evaluating wireless microphones
Published specifications have limited
value in evaluating wireless mic performance. Depending on the manufacturer,
specifications may be exaggerated or
have qualified conditions that may not
be appropriate for your application.
Because RF power output is limited by
the FCC, most systems operating in the
same band provide comparable transmis-
RF test
Set the receiver squelch for normal
quieting. Remove the transmitter anten-
na, if possible, to induce dropout. Listen
for the squelch action when dropout occurs. A well-designed wireless mic will
minimize the annoying sound of a
dropout.
If an RF spectrum analyzer is available,
check the transmitter spectral purity. A
well -designed and properly aligned
transmitter should not have any spurious
signals within 15MHz of the carrier. This
aspect is especially important in multiple
wireless mic system installations.
If an RF signal generator is available,
apply the generator output to the
receiver input to determine receiver sensitivity. Next, offset the generator frequency by a few kilohertz to simulate
transmitter carrier shift due to aging or
temperature. Most manufacturers specify
± 0.005% frequency stability. At VHF
highband, this is approximately ±8kHz
to ±10kHz.
Now apply a test tone to the signal
generator and measure distortion. A
high distortion level may indicate a narrowband or misaligned receiver.
A wireless mic cannot be better than,
but only as good as, a wired version of
the same type. Because wireless mics are
sophisticated radio systems as well as
audio systems, special care must be
taken in setup. A thorough understanding of the system's features and limitations also is helpful.
1:ä))11
ne_ad
PACO KD -120 can
!!
solve problem and give you Maximum performance with the Ni -Cad battery packs.
PACO BATTERY DEMEMORIZER
/I///
KD-120
By
connecting with SONY
BC
-210
or Panasonic AU -1120. KO
//%/.
///r/r.////%
-ri/i/r
/iiiiiii/iiii
-
after
120 will automatically switch the charger for quick charge
dememorizing the packs.
KO -120
trickle charging system will also
after quick
be engaged
charging.
As
the automatic switch to quick charge engages immediately
after dememorizing channel one. overall dememorizing charging
time is not much longer than charging only.
SPECIFICATIONS)
MOOEE
KO
CORE
DEMEMORILABLE
CONNECTABLE
INPUT
BATTERY
PACK
Ni
-Cad battery pack
SONY BC
CHARGER
AC1204
POWER
CHARGING
001SCHARCE
CURRENT
PACO Ni -Cad BATTERY PACK
120
DP-12 11112%.-L111
l.5Ah-6Ah
Panasonic AU -8120
±10%
POWER
OPERATIONS
50
60Hz
OVA
Trickle charge
100mA
4A (Fixed
current)
Sequential discharge mode
Automatic switching
mode, then
EXTERNAL
210,
12V
DIMENSIONS
ELECTRONICS U.S.A. INC
to quick charge mode after discharge
to trickle charge
mode
W9.8"xK3.2"xD12.7"
WEIGHT
8.218s
714 West Olympic Blvd., Suite 706 Los Angeles, CA 90015
T E L:213-747-6540/TLX:756923/ FAX:213-747-3731
Circle
118
Broadcast Engineering
(841
on Reply Card
September 1986
www.americanradiohistory.com
SEEK PROFESSIONAL HELP.
42B 2 -Track Recorder/Reproducer
Hour after hour in a padded room can drive you
a little close to the edge. And you
don't need any extra trauma from
your 1/2 -track.
Tascam's new 42B 2-channel, 2 speed, 2 -track recorder/reproducer
will take your day -in, day -out, all -
day, all-night schedule in stride.
And features like +4 dBM XLR in
and out, balanced mic inputs for
field use, 250/320 nWb/m, and
front -panel controls reduce stress in
even the most harried engineer.
Call or write TASCAM for the full
story on the 42B. Because it's a
Circle (85) on Reply Card
www.americanradiohistory.com
crazy world out there. And there's no
shame in seeking professional help.
TASCAM
TEAC Professional Division
7733 Telegraph Rd. Montebello, CA 90640
Telephone: (213) 726-0303
'Showpreview!
14
Tuesday
October
1986
SBE convention to be
showcase of activities
By Brad Dick, radio technical editor
The
Society of Broadcast Engineers
(SBE) will hold its first national convention Oct. 14 to 16 at the St. Louis Conven-
tion Center. The event will be a
showcase for society activities and will
launch the SBE into a new level of
visibility in the broadcast community.
The SBE regional conventions will continue to be an important element of
society activities, but the October gathering will provide a central focus for the
national organization.
The convention, directed toward the
needs of broadcast engineers, will consist
of two primary elements: a large exhibition of broadcast equipment and a handson technical conference. The exhibition
will be comprised of about 225 booths
with more than 110 equipment manufacturers in attendance. Because of the emphasis on engineering (rather than programming and management), many
booths are being planned with the working engineer in mind. Attendees are
assured of having ample opportunity to
discuss equipment operation and application during the show.
Engineering conference
The Broadcast Engineering technical conference is being arranged by John
Battison, well known through his work at
the annual WOSU conferences. The
technical sessions will cover topics ranging from new FCC radiation standards to
folded monopole antennas. The conference will feature a balance between
radio and TV sessions. In response to
many requests, the hot new topic of zero
setup for TV systems has been added to
the conference. A special presentation
on zero setup has been scheduled for
Wednesday, Oct. 15, at 3 p.m. Engineers
concerned about setup procedures for
new equipment will want to attend.
Tuesday, October 14
The Wednesday luncheon will be a
highlight of the conference. The featured
speaker will be Tom Keller, vice president for engineering at the NAB. Also appearing will be Jim McKinney, chief of
the FCC's Mass Media Bureau. McKinney
will host a short question-and-answer
session after the luncheon.
At the luncheon, Richard Rudman,
SBE president, will present the first SBE
Industry Award. The award recognizes
an individual who has made a special
contribution to the broadcast industry.
The late Harold Ennes is the recipient of
the 1986 SBE Industry Award, which will
be accepted by his wife, Mary Lou Ennes.
As most broadcast engineers know, Ennes-a long-time advocate for technical
training-wrote many technical books,
some of which were directed specifically
at the special needs of broadcast
engineers. The award is the highest industry honor SBE confers.
The Broadcast Engineering conference will run for three days, opening
on Oct. 14, one day before the exhibits
open. This will give attendees an opportunity to zero in on sessions of special importance to them. The convention center
exhibit floor will be open on Wednesday,
Oct. 15, from 9 a.m. until 6 p.m. and on
Thursday from 9 a.m. until 3 p.m.
The 1986 SBE National Convention
and Broadcast Engineering Conference will continue the tradition of the
Central States regional convention of
free admission to the exhibit hall. In
order to cover expenses, a nominal
registration fee will be charged for admittance to the engineering sessions.
www.americanradiohistory.com
The fee has been set at $25 and will be
used to cover the costs of organizing the
program. An additional fee of $10 will be
charged to those who wish to attend the
luncheon on Wednesday, Oct. 15.
Because this luncheon will be the centerpiece of the convention, interest is expected to be high.
Related events
The social aspects of the SBE's first national convention also are important.
Several local SBE chapters have organized car caravans for travel to St. Louis.
By car-pooling, the cost of getting to the
convention can be made quite
reasonable. At least one SBE chapter has
chartered a bus.
Discount air fares are available on
TWA from Apex Travel in St. Louis.
Special 40% discounted fares can be obtained through Apex if you tell the
operator you want the SBE discount. The
SBE profile number for the special rates
is 99-10405. To qualify for the rates, you
must make your reservations through
Apex Travel. Call 800-325-4933. Inside
Missouri, call 800-392-1474. Discount
rates also are available from both the St.
Louis Sheraton and Radisson hotels.
The SBE will be holding several
meetings in conjunction with the convention. In addition to the annual
membership meeting that will take place
on Tuesday at 5 p.m., chairmen, board of
directors and past presidents meetings
will be held.
A ham radio operator reception will be
held immediately after the Tuesday annual membership meeting. The reception begins at 6 p.m. and will include a
cash bar and door prizes. All amateur
radio operators will want to attend.
A Wednesday evening reception,
hosted by SBE, will allow everyone to
Broadcast Engineering
Technical Sessions Schedule
Tuesday, October 14
TV sessions
9:30 a.m. Continental breakfast
10 a.m. Opening remarks, John H.
Battison, conference chairman
Welcome, Richard Rudman,
SBE president
10:30 a.m. New FCC/FAA tower marking and lighting rules, Lew
Wetzel, Flash Technology
11:05 a.m. The travelers information
service, Richard Crompton,
LPB
11:40 a.m.
Audio
specifications-
what do they really mean?
Iry Joel, Iry Joel and
Associates, consulting
engineers
12:30 p.m. Lunch
1:30 p.m. The FCC
2:45 p.m.
3 p.m.
4
p.m.
5 p.m.
6 p.m.
answers back,
John Reiser, FCC
Coffee break
Consultants round table,
moderator, John H. Batti son; panelists: Don Markley, John F.X. Browne, Lawrence Behr, Wally Johnson
and Iry Joel
Engineering management
SBE national membership
meeting
Ham radio reception
Wednesday, October 15
cluding practical applications, Nick Ostroff, Comark
9:40 a.m. A review of videotape formats, Jerry Bauman, 3M
10:15 a.m. Coffee break
10:30 a.m. Tuning and
adjusting TV
antennas with a spectrum
analyzer, Don Markley, PE,
consulting engineer
11:05 a.m. Stereo TV measurement
techniques, Mike Coleman,
Tektronix
11:40 a.m. Enhanced NTSC transmission and spectrum sharing
with the land mobile service, John F.X. Browne, P.E.
consulting engineer
3 p.m. Zero setup for video
Joint sessions
12:30 p.m. Tom Keller, NAB, and Jim
McKinney, FCC, will speak
at TV/radio luncheon
5
Question/answer session
with Jim McKinney
p.m. SBE chapter chairmen's
7
meeting
p.m. SBE reception
2 p.m.
Thursday, October 16
Radio sessions
Continental breakfast
8:30 a.m. The care and feeding of
folded monopole antennas,
Lawrence Behr, consulting
radio engineers
8 a.m.
Fine-tuning
FM final
stages, Geoffrey Mendenhall, Broadcast Electronics
9:40 a.m. Tuning and adjusting pulse modulated transmitters for
9:05 a.m.
8 a.m. Continental breakfast
8:30 a.m. Switchless RF combiner for
TV, Greg Best, Harris
9:05 a.m. Recent developments in
klystron technology, in-
8 a.m. Continental breakfast
8:30 a.m. Transformer rewinding
techniques,
10:15 a.m.
10:30 a.m.
optimum performance,
David Chenowith, Continental Electronics
10:15 a.m. Coffee break
10:30 a.m. Grounding to
hum and RFI,
eliminate
L.
11:05 a.m.
Scott
Hochberg, Logitek
11:05 a.m. Synchronizing AM transmitters, Oscar Reed, PE, con-
11:40 a.m.
sulting radio engineer
11:40 a.m. Digital audio basics, John
Woram,
Digital Audio
Reports
gather in a relaxed setting. Scheduled are
live band music, dancing, a cash bar
and hors d'oeuvres.
Another group also is using the SBE
convention as an anchor for its activities.
The Community Broadcasters Association (CBA) has decided to hold its
meetings in conjunction with the SBE
show. The CBA announced its intention
Peter
Dahl,
Dahl Transformer Company
9:05 a.m. RF radiation and the broadcaster, Richard Tell, EPA
9:40 a.m. FM allocations and applica-
12:30 p.m.
tion processing, Harry C.
Martin, attorney
Coffee break
The effect of antenna bay
spacing on downward
radiation, Robert Surette
and Peter S. Hayes, Shively
Labs
A variable -speed CD player,
Bill Sacks, Straight Wire
Audio
Computerized engineering
information, Robert Kircher, Dataworld
Conference closing
remarks, John H. Battison,
conference chairman
to participate with SBE in late July. The
addition of the CBA is expected to add
several hundred attendees.
The SBE National Convention and
Broadcast Engineering Conference is
ready to go. All indications point to a successful program for attendees, exhibitors
and the society. See you in St. Louis!
Improve ttie
sound of
your "actualities" with
close-up audio
even when
you're at
telephoto
range. Use
our Short
Shotgun or
one of our
Big Guns.
Choice of
battery or
phantom
powering.
Easy to
hand -hold,
fishpole, or
boom mount.
Complete with
full-length
windscreen.
But the sound is
the clincher: So good
every major network has
bought A-T shotguns ...
and saved a bundle
compared to older designs.
Get the facts from your
A-T dealer or write for complete Audio-Technica AT800
Series catalog and dealer
list today.
audiotechnlcaa
1221
Commerce Dr., Stow, OH 44224
(216) 686-2600
Circle (97) on Reply Card
www.americanradiohistory.com
Showpreview
Friday
October
24
1986
The focus will be
on film and TV
By Carl Bentz, TV technical editor
Not
everyone who's in New York on
Oct. 28 will be there to attend the 100th
birthday celebration and rededication of
the lady in the harbor. Members of the
Society of Motion Picture and Television
Engineers will be there for the 128th fall
SMPTE technical conference and equipment exhibit, which runs Oct. 24 to Oct.
29 at the Jacob K. Javits Convention
Center.
The technical conference and equipment exhibit schedule is unusual this
year in that it will begin on a Friday, extend through the weekend and conclude
on a Wednesday. Previous conferences
always scheduled most activities during
the week. The different format should
allow attendees additional time and opportunity to take in the exhibits and
technical program sessions.
The technical program
Both film and television will be
spotlighted during the week. Industry
representatives from around the world
will attend the program of concurrent
sessions for the two imaging technologies. Six general topics form the tentative schedule for film and five topics will
fill the TV session slate.
The theme for the conference is
Today's Technology-Tomorrow's Reality? In answer to that question, a number
of papers are being considered for
presentation in the sessions.
Unlike previous SMPTE conferences,
high-definition television will not play a
major role in the technical sessions.
Following the failure of the proposed
HDTV standard to achieve approval at
the CCIR meetings in May, an increased
interest in enhanced television can be
expected. Some of the presentations will
discuss advancements made in video encoding for improved NTSC and PAL imaging. Some papers will investigate highdefinition transmission systems that are
compatible with existing transmission
standards.
Improved definition begins with the
TV camera. The CCD as a pickup device,
with and without shutter enhancement,
and improved pickup tubes should be
122
Broadcast Engineering
will
cover some
areas
in
which
computer -assisted operations can
Friday, October 24
Special signal amplitude and timing considerations for the growing use of video
components will prove valuable for
enhance all aspects of the production.
The interest in distribution of data in the
studio for equipment control is expanding. Transmission of digital TV signals
from the studio to the home via fiberoptics suggests the integration of
numerous services in a network -oriented
engineers moving into production
system.
without subcarriers.
As production equipment becomes
more digital in design, the use of computers for processing and system control
will become more prevalent. Discussion
of computer applications in television
Other presentations that are being considered involve adaptive equalization
systems for digital-recording equipment;
designing of new camera/battery interfaces; applications for videodiscs; improved VITS generators and inserters;
high-performance TV cameras; and highpower solid-state TV transmission equipment. Random-access editing, 3-D imaging, video compositing and sync-pulse
generation with logic gate arrays round
out the tentative list of TV paper topics
that have been received at SMPTE headquarters.
New film technologies and considerations for both low- and high-speed
photography will be discussed. Perhaps
your interest is in the increased use of
electronic cinematography in the film industry or a better understanding of 80 -bit
SMPTE time code as applied to film.
Along the lines of visual presentations
will be a film mix theater for video and
speaker directivity considerations for
any size of motion-picture viewing environment.
topics of interest. Signal processing for
effects and system flexibility will involve
parallel video -analog components.
Tentative Conference Schedule
Sunday, October 26
practices-film and video,
part 1
Computer applications for
television
P.M.: Archival film and video
Digital applications for
television, part 1
A.M.: Lab
Monday, October 27
practices-film and video,
part 2
TV sound systems
P.M.: Film and lab technology
Digital applications for
television, part 2
A.M.: Lab
Tuesday, October 28
In the background
A.M.: Film and video post -
production, part 1
Enhancing the theater
experience
TV camera systems
P.M.:
Film and electronic production,
part 1
Enhanced TV systems, part
1
Wednesday, October 29
A.M.: Film and video post-
production, part 2
Audio: "Talkies are back"
P.M.: Film and electronic production,
part 2
Enhanced TV systems, part 2
September 1986
www.americanradiohistory.com
With industry leaders from around the
world to be assembled at the convention
center, a number of the SMPTE working
and study groups will meet to continue
developing standards for many aspects
of film and television. More information
on setup in mixed component/composite
video facilities can be expected, along
with closer definitions of analog- and
digital-component recording systems.
Studies of the problems of component
distribution in video facilities will continue, but because of the sensitive nature
of some of the working and study group
discussions, these meetings may not be
Best Show on Wheels. The New Video 20
Pedestal System.
When you and your EFP camera are on
the go, get maximum portability plus studio
comfort with the Video 20 Pedestal System
from Sachtler. A pneumatically supported
center column with its pressurized balance
system provides multiple load capabilities for
smooth and precise on air movement. The
steerable dolly assures equally smooth and
precise tracking. Also, the Video 20 Pedestal
can be combined with the Sachtler Semi -Dolly
or used as a stable, stationary unit. For lightweight portability and professional results,
the Video 20 Pedestal System proves itself a
champion in action. Everywhere. Every time.
Of course all Video 20 Pedestal System combinations come with Sachtler's guaranteed
leakproof fluid heads for the ultimate in
smooth, precise shooting.
That's what we are known for. Worldwide. For detailed information, please contact
-"
11111
IIII
I,ourIIÍII'JlIIIP
us.
Sachtler. The System.
Sachtler Corp.
400 Oser Avenue
Hauppauge N.Y. 11788
Phone (516) 231-0033
Victory Blvd.
Burbank, CA 91505
Phone (818) 845-4446
3316 W.
Sachtler GmbH Dieselstr.16,
D-8046 Garching/München,
West Germany.
Visit Us in Booth #946, SMPTE
Circle (88) on Reply Card
www.americanradiohistory.com
"T
I
open for public attendance.
A report on the SMPTE task force that
was established in 1985 to study and
analyze the society's standards procedures may be forthcoming. The task
force consists of legal representatives
from manufacturing and broadcasting
companies that make up the SMPTE
Presidential Advisory Council. One major goal of the group is to determine if
more expedient methods are available
for standards development.
N
CENTRAL PARK
ZOO
LINCOLN CENTER
The special events
The annual Eastman Kodak reception
is scheduled for Friday evening. For
those who have not attended one of
these receptions in the past, be prepared
for a pleasant evening and the chance to
meet many SMPTE colleagues.
Roland Zavada will be the speaker for
the SMPTE Fellows luncheon, Sunday,
Oct. 26. He is the recipient of the
society's Progress Award in 1985 for his
work in developing Super 8, Instamatic
and instant photography systems.
Zavada has been a key participant in
developing test procedures to optimize
telecine setups with color films. He also
was instrumental in safe action and safe
title areas for TV viewfinder and monitor
displays. Zavada is responsible for drafting standards proposals for Super 8 for
the American National Standards In Continued on page 128
I
1 59TH STREET
W
Z
W
>
HUDSON
RIVER
a
zW
c>
o
W
W
Z
Z>
>
>
W
D
>
Z
W
á
Z
r-
m
W
x
fm
W
oco
Z
>
ROCKEFELLER
CENTER
x
n
I42ND STREET
LINCOLN
TUNNEL
JACOB K. JAVITS
CONVENTION
CENTER
a'H
EMPIRE
STATE
BUILDING
34TH STREET
(
I
I
MADISON
SQUARE
GARDEN
1. This sketch of a section of Manhattan Island shows some well-known landmarks and
the location of the Jacob K. Jauits Center.
Figure
LIGHTS! CAMERA! HANNAY!
Fast pick-up. Increased safety.
Greater mobility. You get it all with
Hannay Cable Reels. Available
--in portable or stationary models, ' '
these dependable reels safely'-`
handle electrical cable.,
Count on them for timesaving rewind. Easy storage. And all the behind the -scenes operating convenience you'll ever need. Send today for more information _ ..
on the full line of Hannay Cable Reels,
available in a wide selection of sizes,.
Send Today For Free
Literature Packet.
HANNAY
REELS
CLIFFORD B. HANNAY & SON, INC., 600 EAST MAIN STREET
TELEPHONE (518) 797-3791
WESTERLO, NEW YORK 12193
Circle (87) on Reply Card
124
Broadcast Engineering
September 1986
www.americanradiohistory.com
THE PERFECT ECLIPSE
THE
ECLIPSE
EDITOR
1X
AUDIO KINETICS
EC LI
P
AUDIO KINETICS INC
1650 Highway 35,
Suite 5, Middletown,
New Jersey 07748, USA.
201-6718668 Fax: 201 671 6902
AUDIO KINETICS INC
4721 Laurel Canyon Blvd,
Suite 209, No. Hollywood,
Cal 91607, USA
818-980-5717L Fax: 818 7613916
pace
THE ECLIPSE EDITOR
A technological phenomenon in the form of an Intelligent
Audio Edit Controller which puts rival products in the
shade. Having a capacity to control a large number of
events, firing complex user -programmable sequences in
perfect alignment from a single
Q -key,
The Eclipse is
capable of supporting 32 machines.
Many of The Eclipse's unique functions were beyond the
wildest imagination of Audio engineers until Audio
Kinetics applied their advanced research technology to
create an electronic edit controller which will, when
interfaced with Q -LOCK Synchronisers, add a little magic
to modern post production facilities.
Circle (72) on Reply Card
www.americanradiohistory.com
SS
ENGenius!
KEGAM HL-95 IS
THE CROWNING ACH EVEV ENT OF THE 80s.
I
I
I
The engineers at Ikegami have just enhanced the finest ENG component camera in
the industry, by making it the most versatile.
Now the Ikegami HL-95 camera head
can be the crown jewel of your '/2' Beta ENG
system, as well as three other configurations
including 3', '/4" and MII formats.
Considered by many as the most impressive and important hand-held camera
breakthrough of the 80's, the HL-95 achieves
total operational flexibility without compromising strict performance, sensitivity, resolution and registration.
Featuring registration stability without
adjustment (proven over many weeks); better shoulder balance; better low light level
sensitivity (1.5 ft. candles); better S/N for
given low light levels (proven in exhaustive
comparison tests); plus minimum maintenance, weight and power consumption. The
Ikegami HL-95 far outdistances any camera
in its class. It's pure ENGenius.
For a demonstration of the HL-95 and
other Ikegami cameras and monitors, contact us or visit your local Ikegami dealer.
"N .V. Philips
www.americanradiohistory.com
Circle
190)
on Reply Card
ç.
Ikegami Electronics (USA), Inc. 37 Brook Avenue Maywood, NJ 07607
East Coast: (201) 368-9171 West Coast: (213) 534-0050 Southeast: (813) 884-2046 Southwest: (214) 233-2844 Midwest: (312) 834-9774
www.americanradiohistory.com
Continued from page 124
We've taken apart half a million
videocassettes and saved our
customers 2 million dollars
Before we'll reload a 3/4" u-matic videocassette we take it completely apart and
rebuild it inside and out. We replace wiper flaps, friction pads, tape guides and
leader
everything that's needed to make the cassette test as good as new. Only
then will we reload it with new 3 M videotapes or other major brands. If we can't
rebuild it we won't reload it.
Coarc also loads new cassettes with broadcast quality videotape for Betacart
and 3/a" cart systems.
-
v vÑ V
IV
%Or
W N
Custom Loaded Videocassettes (518) 672-7202
P.O. Box 2, Route 217, Mellenville, New York 12544
3/4" RELOADING
D PROFESSIONAL VHS
& BETA
1/2" AND 3/4" CART CASSETTES
Circle (91) on Reply Card
SESCOM, INC.
i3éí
éñm
"the audio source"
FOR ALL OF YOUR AUDIO NEEDS
2100 ward Drive Henderaon,NV 89015 U.S.A.
CALL TO RECEIVE A COPY OF
Sales-Service
OUR POCKET -SIZED CATALOG
(800)834-3457
OTHER BUSINESS: (702)585-3400
CATALOGS
RIO
&
Broadcast Cartridge Service
ORDERS:
TWX(910)397-6998_
CART'EM UP ON
AUDIOPAK AA -4!
(714) 898-7224
5ES
CCM
stitute (ANSI) and the International
Standards Organization (ISO). He has
been a SMPTE member since 1962, and
for eight years, served as engineering
vice president for the society.
Attendees of the honors and awards
luncheon, Monday, Oct. 27, will hear Dr.
George H. Brown, a former engineering
executive with RCA. During his tenure
with RCA, in the era when color TV
technology evolved, Brown was responsible for the company's research,
engineering, patenting and licensing
operations.
The exhibits
The list of equipment manufacturers
continues to grow. Unlike past New York
SMPTE conferences, this year's event is
not confined to hotel ballrooms. Instead,
the long-awaited Javits convention facility will play host. Approximately 300 exhibits will take up three halls on Level I.
An area of 230,000 square feet has been
allocated.
Equipment on display will include
many of the latest analog- and digitalcomponent video equipment; audio
systems to complement enhanced video
technology; and many established audio,
video and film products. Plan to spend a
good deal of time with the products on
display to investigate where the industry
is headed.
Circle (93) on Reply Card
Circle (92) on Reply Card
About New York
Many people attending the conference
will be unacquainted with the Jacob K.
Moving?
Take us with you.
Just peel off the subscription mailing label and attach it to the address change card located at the
front of this issue. Please allow 6-8 weeks to process
your address change.
BRODCST
enGineeRmG
128
Broadcast Engineering
September 1986
www.americanradiohistory.com
Javits Convention Center. The center
spans the area between 11th and 12th
Avenues and 35th to 39th Streets near
Manhattan's West Side. The simplified
map (see Figure 1) notes several wellknown New York landmarks, allowing a
better reference to the convention
center location.
Although the Javits center is advertised as the most modern facility available, it is not necessarily the most conveniently located for conference -goers.
Most of the major hotels are along and
east of Broadway, approximately two
miles away. As a convenience for attendees, shuttle buses will be provided.
Housing for the conference will involve the New York Hilton, Milford
Plaza, Marriott and Sheraton Centre
Hotels. Society members will be able to
enjoy a reduced convention rate when
they return registration material requesting lodging.
For information
To get preregistration information and
forms, contact SMPTE at its new location, 595 West Hartsdale Ave., White
Plains, NY 10607; telephone 914-7611100.
For information about New York, contact the New York Convention and
Visitors Bureau, Two Columbus Circle,
New York, NY 10019.
I: ))))I
Canon ualîty. Canon Value.
Now available'in a full line of camera support products.
MC-200/MC-300 PEDESTALS
TR-60/TR-90 TRIPODS
Featuring Canon's sophisticated Modular Cassette Counterbalance (MCC) system that
makes -hem far lighter and
more mobile, Canon pedestals
also feature a very short
mounting height, making them
ideal for low -angle shooting.
Featuring collapsible tubular
leg construction, integral
spreaders, flip-tip legs with
spikes and rubber padding.
TR-60
Maximum Mounting Weight:
TR-90
Maximum Mounting Weight:
132 lbs.
198 lbs.
Elevation: 20-45 inches
Elevation: 26-48 inches
MC -200
Maximum
286 lbs.
Elevation:
MC -300
Maximum
242 lbs.
Elevation:
Mounting Weight:
24-49 inches
Mounting Weight:
23-60 inches
CD -10 DOLLY
SC-15 CAM HEAD
Designed for use with all
pedestals and tripods, it features a convenient "V" wedge
mounting system and centerof-graviy adjustment control.
The modular panning rod may
be usec on both sides.
MaximLm Mounting Weight:
Designed for use with both
Canon tripods, features a
tricycle caster undercarriage
that enables both free and
single -direction movement.
Maximum Mounting Weight:
330 lbs.
Tilting: ± 50° Panning: 360°
198 lbs.
Fo' years, broadcasters have made Canon
lenses a top choice for studio, field and news pro diction because they know and trust Canon's proven
commitment to quality and value.
Now Canon is proud to introduce a complete,
full -featured, high -quality camera support system,
built to the same high standards and backed by the
Canon service network.
Caiioit
Optics Division
Canon USA, Inc., Head Office: One Canon Plaza, Lake Success, NY 11042 (516) 488-6700
Dallas Office: 3200 Regent Blvd., Irving, TX 75063 (214) 830-9600. Chicago Office: 100 Park Blvd., Itasca, IL 60143 (312) 250-6200
West Coast Office: 123 Paularino Avenue East, Costa Mesa, CA 92626 (714) 979-6000
Canon Canada, Inc., 6390 Dixie Road, Mississauga, Ontario L5T1P7, Canada (416) 678-2730
41985 Canon USA
Circle (64) on Reply Card
www.americanradiohistory.com
.
Inc
SBE Update/
SBE
helps form NFCC
By Bob Van Buhler
The
uniform data organization system be
used. The software being developed will
allow all frequency coordination committees to use a uniform data system, which
will make data transfer easier. Although
a national frequency database is not yet
in the plan, uniform standards may some
day make that possible.
An early NFCC goal is the rapid adoption of standardized database management software for the top 25 broadcast
markets. With the widespread availability of IBM compatible PCs, the committee
feels that uniformity will then eventually
Van Buhier is chief engineer for WBALAM and WIYYFM, Baltimore.
1
-in
EZ
Society of Broadcast Engineers,
together with representatives from other
major broadcast organizations, formed
an industrywide National Frequency
Coordinating Council (NFCC) at a July
meeting in Washington, DC.
Representatives from ABC, CBS, NBC
and Mutual met with trade associations
including SBE and RTNDA to hammer
out the details of the new organization.
The original plan was to form the
NFCC under the auspices of the NAB as
secretariat. The NAB seemed to prefer a
task force arrangement rather than a formal organization with bylaws. At this
writing, the group had not adopted a formal structure.
Some of the key points of agreement
related to the policy, status and nature of
coordinating at the local level. The council agreed that the key to the whole effort is the local frequency coordinator.
The council also realizes that the human
element cannot be replaced by a computer database. It takes a person on-site
to be able to fully understand the local
frequency situation.
Other policy elements included the
recognition of the need for a handbook
of good engineering practice under Part
74. The publication would illustrate the
proper use of ENG and 2 -way equipment,
the fundamentals of site engineering and
microwave and 2 -way protocol for semi technical and non-technical users. NAB
expressed some interest in helping
prepare this document.
Gerry Dalton, SBE national frequency
coordination chairman, participated in
the development of a uniform software
package. Because of the number of coordinators involved, it's important that a
Broadcast Enaineerinq
follow into most markets. The software
should be ready for distribution to local
committees by early 1987 or sooner.
The key goal of the NFCC is to provide
a unified industry voice on the subject of
frequency coordination. If the users are
unified on such matters as policy and
practice, then the FCC and other broadcast organizations will provide the needed recognition and support.
Special events
Tuesday
SBE national membership
meeting.
Ham radio reception, with
door prizes and cash bar.
5 p.m.
6 p.m.
Wednesday
12:30 p.m.
7
Luncheon.
Speaker will be Tom
Keller, NAB.
Special guests include Jim
McKinney, FCC.
Reception and cash bar.
p.m.
National convention
variety of subjects will be
covered at the SBE national convention
next month in St. Louis. The convention,
scheduled for Oct. 14 to 16, will mark the
first time the SBE has held its own national convention.
John Battison, technical conference
chairman, has provided a schedule that
will answer many informational needs
for both radio and TV broadcast
engineers. Not only will the latest
technical topics be discussed, but recent
FCC regulations also will be covered.
The Wednesday, Oct. 15, joint
radio/TV luncheon speaker will be Tom
Keller, senior vice president, science and
technology, NAB. A special guest at the
convention luncheon will be Jim McKinney, chief of the FCC Mass Media
Bureau. A couple of special surprises also
are planned for the luncheon. The cost of
the luncheon is $10.
An important RF radiation update session will be held on Thursday, Oct. 16.
A wide
September 1986www.americanradiohistory.com
Richard Tell, EPA, will report on the
latest RF radiation field tests. In case you
missed the radiation session at the NAB,
this update session is a must -attend
event. Even if you attended the NAB
convention, the RF radiation session will
provide you with the latest information
on measurement techniques and the
results of the tests that were conducted
this summer.
Exhibits
Sold out! That's the word from the national office. The St. Louis chapter has
been successful in selling out all of the
exhibitor space in the convention center.
More than 110 exhibitors will be on hand
to demonstrate their equipment.
Unlike some conventions, the SBE convention will allow you the opportunity to
really look over the equipment and ask
questions. The exhibitors know that
engineers will be attending the convention, so technical experts will be on hand
to field your questions. Plenty of time has
been set aside for touring the exhibits.
Related events
The ham radio reception will be held
Tuesday evening just after the national
SBE meeting. Door prizes and a cash bar
will be available. A Wednesday evening
reception will be hosted by SBE. Bring
your spouse or a friend and visit with old
friends or make new ones. There are
plenty of activities to keep you busy for
all three days.
Because St. Louis is centrally located,
some chapters are organizing group
travel plans. At least one chapter has
chartered a bus. This is a cost-effective
idea and allows additional social time
during the trip to and from the convention. Other chapters are planning car
caravans. If you travel with a group, the
trip is more enjoyable and you can trade
off driving. If you can borrow a company
car, transportation becomes so reasonable your boss can't say no.
To keep the costs as reasonable as
possible, special discount hotel rates are
available from the Sheraton St. Louis
(314-321-5100) and the Radisson Hotel
(314-421-4000). Special 40% discounted
air fares are available from TWA. Tickets
must be ordered through Apex Travel,
St. Louis. Call 800-325-4933. In Missouri,
call 800-392-1473. Mention SBE and the
profile number, 99-10405, when you call.
:7:4»)1
)))1
EXCELLENCE IN THE
AMERICAN TRADITION
American business tradition is characterized by unsurpassed excellence in service,
reliability and quality. True to this tradition, Gray does it the old-fashioned
American way-we do it right the first
time!
ALBANY, GA (912) 883-2121
ATLANTA, GA (404) 956-7725
BATON ROUGE, LA (504) 928-1171
BIRMINGHAM, AL (205) 942-2824
CINCINNATI, OH (513) 896-1011
Teamed with quality cameras from
Ikegami, Gray offers the finest equipment and over a decade of video
engineering expertise. Call your local
Gray office for excellence in service,
reliability and quality.
FT. WALTON BEACH, FL (904) 651-8546
FT. LAUDERDALE, FL (305) 523-3637
N. LITTLE ROCK, AR (501) 758-3234
MEMPHIS, TN (901) 525-1135
GAINESVILLE, FL (904) 332-2436
HUNTSVILLE, AL (205) 881.5840
KNOXVILLE, TN (615) 588-7161
MIAMI, FL (305) 591-3637
MOBILE, AL (205) 476-2051
NASHVILLE, TN (615) 883-9175
NEW ORLEANS, LA (504) 733-7265
(504) 733-7290
ORLANDO, FL (305) 896-7414
ST. PETERSBURG, FL (813) 823.6840
TAMPA, FL (813) 885-1411
GRAY
,t\Y
CONSUL ANTS
T
404 SANDS
DR.
ALBANY, GA 31705
[912) 883-2121
Circle (86) on Reply Card
www.americanradiohistory.com
TWX
I
#
NIC
B10-781-5110
Freeze.
Introducing the fastest,
easiest way to get quality
prints and slides from video.
Now you can capture the
moment, freeze it, and frame it. All
with the touch of a button.
With the new FreezeFrame
Video Image Recorder from
Polaroid.
FreezeFrame produces sharp,
instant color prints and color or
black and white 35mm slides from
virtually any video source. And it
delivers a finished picture that is
far superior in quality and resolu-
132
Broadcast Engineering
tion to direct screen photography
or thermal video image recorders.
If you use video, you need
FreezeFrame.
print off a j ust-breaking news story,
or for color correcting a proof. It
can even help in film-to-video transferring. Medical professionals can
use FreezeFrame
came for diagnostic
recording, patient
referral or teaching.
And it's the easiest
way to get slides or
prints for presentations or training.
FreezeFrame has hundreds
of uses for anyone
who uses video
in their profession. It can be
used in broadcast,
production and advertising to proof, _444013iitwas
FreezeFrame
-"edit, storyboard
can improve
or reference. It can System includes Video Image Recorder,
your image.
be used to pull a control console, and print film camera/adapter. FreezeFrame
35mm camera/adapter optional.
September 1986
www.americanradiohistory.com
Frame.
connects easily to video cameras,
professional VCR's, laser disc
players and computer graphics
systems.
You can preview and even
improve the video image because
FreezeFrame has a full range of
image enhancing controls including
tint, contrast, color, sharpness,
brightness and raster fill. And if
you're shooting prints, Freeze Frame uses a new color print film
specially developed for use with
video imaging.
New FreezeFrame from
Polaroid. It's fast, easy, and at
$1,899* very affordable.
To find out how FreezeFrame
help
you, call toll -free 800-225can
1618, 9 a.m. to 6 p.m. Eastern Time.
Or fill out and return the
coupon. We'll give you the full picture and show you just how easy it
can be to capture the moment on
FreezeFrame.
Polaroid
I
ior more information, mail this
coupon to Polaroid Corp., Dept. 671,
P.O. Box 5011, Clifton, NJ 07015.
Please send more information.
8E911
I'd like a demonstration.
Name
Title
Organization
Address
City
State
Telephone
Video Source
Application
Zip
'Suggested list price. "Polaroid"® "FreezeFrame '" ©1986 Polaroid Corporation
Circle (98) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
133
Station-to station
Monitor modification
eliminates squeal
By E. J. Alexander
Sometimes a small change can be made
equipment's operation that will improve its performance. Although it's
seldom proper to permit significant
changes in an equipment's design,
sometimes slight alterations are useful.
Such is the case with the TFT model
753 AM modulation monitor. The
monitor is a common piece of equipment
in AM stations, so the change I'm suggesting may be useful to many stations.
The modulation monitor produces an
ear-splitting squeal when placed in the
calibrate mode. Typically the monitor's
audio output jack drives the control
room speakers. So, when the monitor is
switched to calibrate, anyone listening to
the air signal is overwhelmed by this
squeal. If the monitor's output jack feeds
the station's entire monitor system, then
everyone in the station is forced to endure this high-pitched tone while the
engineer checks the monitor's calibration. There is, however, a simple
modification to prevent this squeal.
Another modification
in an
While you have the cover off the
monitor, you might want to make
another small modification. Installing
ECG -417 transistor sockets on the ends of
the meter lamp power leads makes
replacement of meter lights much easier.
These sockets make excellent connectors for No. 7382 lamps. This particular
lamp operates at 14V, 0.08A and is rated
for 40,000 hours. Once you've made this
change, replacing lamps will no longer
require a soldering iron and a trip to the
bench.
I:r4)))j
the back of the PC board. Also, be careful
that you don't develop a solder bridge
from the pads to the ground plane. The
modified circuit is shown in Figure 2.
After the modification is completed,
check out the monitor's operation. You
should no longer hear the squeal when
selecting calibrate.
Figure
BACK PC BOARD OF 753
1. Connect the shielded audio cable
from the back -panel audio jack to the frontpanel calibrate switch.
BLK
RED
J
ORIGINAL JUMPER-REMOVE
SHIELD
Making the change
This modification mutes the audio output when the calibrate mode is selected.
The only part required is a short length
of shielded 2 -conductor audio cable.
The calibrate switch has an unused
SPDT section that can be used. By looping the audio signal through this switch,
you can prevent the annoying tone. The
switch simply interrupts the audio feed to
the output amplifier, Z14.
The modification uses the front three
terminals located toward the left edge of
the PC board as shown in Figure 1. Do
not use the outside back terminals. This
unused section is connected to the PC
board ground plane. Connect the cable
to the switch as shown in the drawing.
To complete the modification, remove
the original jumper from the PC board
where the whistle filter switch would
connect, if used. This modification
assumes that the whistle filter option is
not installed on the monitor. If the whistle filter is being used, it will be necessary
to cut a foil on the PC board or break one
lead of either capacitor C12 or R37.
Attach the shielded cable to the switch
as shown in Figure 1. Be certain that you
attach the shield to the ground plane at
Alexander is technical
Russellville, AR.
134
director
for KARV-AM,
BLK
RED
N
R
¢
C62
R38
C61
WHISTLE
FILTER
JACK
BACK PANEL
FRONT -PANEL
CALIBRATE SWITCH
WHISTLE
FILTER
SWITCH
OUT
J12
AUDIO
OUTPUT
15MFD
Figure 2. A schematic diagram of the
modified circuit
Broadcast Engineering September 1986
www.americanradiohistory.com
10K
150pF
TO BACK
PANEL J7
Teiemeirics
camera remote -control systems
FOR IKEGAMI HL -series CAMERAS
specify Telemetrics Type TM -8505.
BVP-series CAMERAS
specify Telemetrics Type TM -8640.
FOR SONY
Telemetricscamera
a
taflters
standard
battery
pack
_your_
camera
SONT
N
elemetrics
remote -
Telemetrics
control
unit
station
base
Tlemetrics
Made in
U.S.A.
VM
PE..rf
00.
ELK MliNlCf
NM.
,MC.
remote
control
camera video from camera
externat video to viewfinder
interphone (bi-directional)
microphone audio from camera
genlock to camera
over distances (up to) 2500 feet
using standard co -axial cable
For Complete Telemetrics Canon
CCD Camera & Pan
Tilt Table Systems
specify TM -8600 -series
For standard
ENG
cameras
specify
Telemetrics
Type TM -8605 -series
PAN/TILT TABLES
camera mounts on & rotates around
center line of Pan.,Tilt Table.
interconnections to camera made
through Pan/Tilt Table, providing for a single cable
from PanTilt Table.
interconnection box connects to
& from signal sources & power.
pedestal, tripod or ceiling mounts.
Optional: servo or manual drive.
FOR INFORMATION
CALL
(201) 423-0347
Circle (130) o^ 7,eply Card
G,r
Q,
`.
.
'c.snc.
Valley St.Hawthorne,N.J.07506
SEE Telemetrics AT SMPTE/NEW YORK BOOTH 1174
7
www.americanradiohistory.com
/People/
L. Sanders and Donald F. Bogue
have been promoted to new positions
with Ampex, Redwood City, CA. Sanders
is vice president of marketing and new
technology, a newly created position. He
is a former vice president and general
manager of the Audio -Video Systems
Division (AVSD) since 1983. Sanders will
examine the markets and technologies of
each division, evaluate its resources and
identify and develop opportunities for
growth. Bogue succeeds Sanders as the
vice president and general manager of
AVSD. He is a former vice president and
general manager of the Magnetic Tape
Division for the past two years.
Mark
Saul Walker, Ralph Moss, Jerry
Barnes and Allen Rumbaugh have
been appointed to positions with Mitsubishi Pro Audio Group, San Fernando,
CA. Walker is manager of broadcast marketing for the New York regional office.
He is responsible for sales for the professional audio and film equipment. Moss is
Eastern regional sales manager. He will
support sales efforts for the professional
audio recording products into the recording studio market. Barnes is an informal
adviser. He will talk to potential users of
Mitsubishi's digital audio products. Rumbaugh is regional sales manager for the
Mid -America district, which includes the
Southeastern United States and extends
from Nebraska east to Virginia. He will
be responsible for sales and promotion of
digital audiotape recorders, analog music
and film consoles and magnetic and optical film products.
sible for the sound contracting and sound
reinforcement segments of the professional audio business. He will direct the
marketing programs and assist in product development. Braithwaite is central
regional sales manager. He will manage
the sales support structure of the Central
United States. Murray is Western
regional sales manager. He will be in
charge of RAMSA's sales support network, interfacing on a regular basis with
distributors and end -users.
Norman H. Pond has been elected as
Tom Harmon has been appointed production manager for Orion Research,
Cleveland. He is responsible for
manufacturing, testing and shipment of
executive vice president of Varian
Associates, Palo Alto, CA. He will continue as president of the Electron Device
Group, a position he has held since joining the company in 1984.
Chris Foreman, Greg Braithwaite and
James Murray have been appointed to
positions with RAMSA, Panasonic Industrial Company's professional audio
products operation, Cypress, CA.
Foreman is marketing manager, respon-
all products.
Thomas W. Knauss, James Ritz and
Jerry Williamson have been appointed
to positions with the audio systems division of Peirce -Phelps, Philadelphia.
Knauss is sales engineer. Ritz is senior
audio engineer. Williamson is a sales
representative.
For fast, accurate service, please remove the peel off label used to
address your magazine, and attach it to the Reader Service Card,
the Address Change Card or to any correspondence you send us
regarding your subscription.
136
Broadcast Engineering
September 1986
www.americanradiohistory.com
THE NEW TSM-60 WAVEFORM MONITOR & VSM-60 VECTORSCOPE
----5
-'0
fl0
so
I,
,
2
,.
IJ
.E
i
4 vinw+T
.---_
EL
.
w
".7.0/10.1
_
'
d
Tgid-8o
.
n,+C
Both available in PAL and PAL -M standard.
Simply the Best.
Prove it, you say? Frankly,
Performance:
In frequency response tests, the
Waveform Monitor is flat to 10 MHz and
is as accurate at 20 MHz as most others at 5!
T:SM -60
Features: The TSM-60, with its impressive array
of standard features, is the only waveform monitor to offer both Line Select and selectable
IH/2H Display Modes.
Delivery: You don't have to wait months or even
weeks for a waveform monitor or vctorscope.
use
welcome the opportunity.
Videotek sets the industry standard by consistently delivering in just days!
Support: If you ever need an answer or technical
backup, you can count onus. Our "Distinguished
Video Industry Service Award" attests to that.
Value: Compare Performance vs. Cost of the
TSM-60 and VSM-60 to any others in our field,
and you'll find none better.
Need more proof? /f so, we invite you to personally evaluate the 7SM-60 Waveform Monitor and
VSM-60 Vectorscope in your own facility. Contact your Authorized Videotek Dealer or the Videotek
office nearest you, and we
arrange foryou to prove to yourself what we mean by Simply the Best.
VIDEOTEK
2
Fi Shoemaker Road, Pottstown, PA 19464, (215) 327-2292. 7WX 7I0-653-0125. 9625 North 21st Drive, Phoenix, AZ 85021,
1986-Videotek,
Circle (99) on Reply Card
www.americanradiohistory.com
(602) 997-'523. TWX 910-951-0621.
Frank Scarlata has been named acting
Ted Valand has been named to a posi-
general manager of the Detroit branch
operation for Victor Duncan, Irving, TX.
He also heads the national lighting program for the company.
tion with BASYS, Mountain View, CA.
He is vice president and general
manager of North American operations.
He will oversee the expansion of
research and development efforts,
Thomas Sutton
has been named
Southwest district sales manager for
Sharp Electronics' professional products
division, Mahwah, NJ. He will cover
Texas east of El Paso, Mississippi,
Oklahoma, Louisiana and Arkansas.
Suzanne Foster
of Audio Kinetics Ltd.,
England, has been appointed marketing
coordinator. She will continue to work in
advertising and organizing exhibits. She
also will be responsible for generating
and coordinating all public relations.
Lori Heller and Andy Lovell have been
appointed to positions with Radio
Systems, Edgemont, PA. Heller is vice
president of operations and Lovell is vice
president of broadcast installations.
develop and implement marketing programs and strengthen product and
customer support for broadcast
automated newsroom systems.
Adolfo Rodriguez has been appointed
marketing product manager for System
One audio test equipment for Audio
Precision, Beaverton, OR. He is responsible for customer applications publications and technical marketing activities.
Robert A. Slutske and Gary Schultz
L.
James Beckman has been appointed
to a position with Shook Electronic
Enterprises, San Antonio, TX. He will
head the marketing and sales activities.
Financial considerations for major investments in ENG, EFP and satellite
news gathering is one of the first areas
he will develop.
A
F
Roy Varda, Janice Haigney, Tom Carrigan and Jim Martin have been named
to positions at Quantel, Palo Alto, CA.
Varda is district manager for New York
and south through Virginia. He will
maintain network accounts in Manhattan
and all other accounts in the Mid -Atlantic
states. Haigney is district manager of
New York and north, covering New York
and New England. Carrigan is Southwest
district manager. He will cover Southern
California, Nevada and Arizona. Martin
is special projects manager. He is responsible for new product introductions and
the integration of Quantel products into
existing systems.
R-
have been appointed to positions with
Ampex audio -video systems division,
Redwood City, CA. Slutske is senior
product manager of video editing
systems. He will manage the marketing,
manufacturing and engineering of video
editing equipment. Schultz is product
marketing manager of editing systems.
:r. -1))I
R
E
/lfff(fff/I/lN(NtHffNf(t[[I1111/I(Hlfllfflfflt(hffll(IMIIIHtlfllffitft(}ffillttlltlltlll(t*
Wireless mobility and the future of
shotgun microphones.
Rapidly evolving film, ENG and EFP technologies demand accuracy, better sound and more.
Beyer shotgun mics add the mobility of wireless to
the longest available reach for new applications,
new possibilities.
Beyer has developed a comprehensive system
with the expanded versatility required of a modern
shotgun. Our CK 706 and CK 707 shotgun capsules (part of the MCM condenser system) interface with the Beyer Wireless System. This true
diversity system has totally reliable glitchfree
signal scanning and virtually inaudible LN companding for unparalleled sonic integrity. The wireless option lets you work from the optimum position in relation to the source, to maximize SIN
-
ratios and minimize off-axis interference without
the hazards and inconvenience of long cable runs:
-
Shotguns that stay with the source,
even when far away.
The new performance standards implicit in the
Beyer MC 736 short shotgun and MC 737 long
shotgun (cabled) enable them to cope with the wide
range offield conditions. Both are designed with
extremely low self-noise (-13 dB) and coloration
for critical studio or location situations requiring
absolute silence. Yet they can also withstand up to
135 dB as protection against radical surges in
volume.
The MC 737's tight, highly directional lobe pattern and longer barrel provide the longest reach
and highest sensitivity when isolating sources
ACCURACY IN AUDIO
138
Broadcast Engineering
September 1986
www.americanradiohistory.com
Business
Marconi receives IBA order
Optical Disc delivers videodiscs
The IBA has placed an order for B7500 series UHF highpower TV transmitters with Marconi Communication
Systems, Chelmsford, England. They will replace a number of
the IBA's existing transmitters.
Optical Disc Corporation, Cerritos, CA, has announced the
delivery of its PAL standard videodisc recording system to
Paris. The ODC 620 delivery marks the first time single copy,
fast turnaround videodiscs are available in Europe and in the
PAL format. Installed at GESCO, ODC's European distributor,
the system will serve as a demonstration unit for the growing
European videodisc market.
Kodak opens technology center
Eastman Kodak Company, Hollywood, CA, has opened a
film and video marketing and technology center. The center
will be a staging ground for delivering and supporting the implementation of new imaging technology. The facilities are
built around the building that Kodak first occupied in 1927.
Conus receives SNG trademark
Conus Communications, Minneapolis, has announced that
SNG has been designated as a registered service mark of
Conus by the United States Patent and Trademark Office.
Microdyne's CIM in use by TRN
The Tribune Radio Network, based in Chicago, is initiating
a service to affiliates using Microdyne's Communication Information Manager, a system for electronic distribution of information via a single-channel -per-carrier satellite system from
Microdyne, Ocala, FL. The CIM enables the network operator
to make use of dead air time to transmit news flashes,
weather alerts and text data to individual stations, groups of
stations or to the entire network.
Broadcast Systems completes projects
Broadcast Systems Inc., Austin, TX, has announced the
completion of design and construction of WNTZ-W, Natchez,
MS. WNTZ-TV signed on the air Nov. 16, 1985. The independent operation is built around BSI's DC-8 automatic video cart
machine.
BSI also has completed studios for KSCH -TV, Sacramento/Stockton, CA. The contract called for design and construction of technical facilities.
A
Database provides information
The Broadcasters Database, Houston, an information
storage and retrieval service, is now accessible from more
than 600 cities and 70 foreign countries. Broadcast professionals can obtain timely industry news and show preparation
material as well as useful software that simplifies station
operations. Many trades and periodicals are available electronically on the BDB weeks before they arrive in the mail.
N G
C H
rom long distances.
To reduce off-axis coloration
a.1d low end distortion, the Beyer-lobe pattern
sways tighter in the critical region below 200 Hz.
For even greater control, all of our shotguns are
supplied with built-in bass rolloff filters and -12
dd attenuators. Exceptionally quiet at the critical
outer limits of the lobe pattern, the MC 737 allows
optimum signal to noise (74 dB) at the source
point to further maximize the already extended
reach of the microphone.
Designs that perform with test bench
accuracy in real world use.
Field production can test the will and the equipment with unfamiliar terrain and fast -changing
atmospheric conditions. Beyer shotguns are constructed to new standards of ruggedness and relia -
bility to prevent downtime. Internal shock mounts
reduce handling and boom noise. For maximum
flexibility in the field, the MC 736 and MC 737
are phantom-pozvered and compatible with any
source from 12 to 48V. Beyer's comprehensive line
of pistol grips, windscreens and shock mounts
meets any studio or remote linking situation.
European engineers already know about the expanded range and applications possibilities of Beyer
shotguns. The best way for you to appreciate the
advantages of a Beyer shotgun mic is to rent one.
Beyer Dynamic Inc. 5-05 Berns Avenue, Hicksville, NY 11801, (516) 935-8000
Canada: El Nova Ltd., 4190 Sere St., St. Laurent, Quebec, Canada H4TL46
England: Beyer Dynamic (G. B. Ltd), Unit 14, Cliffe Industrial Estate,
Leines BN8 611 England
Germany: Engen Beyer Elektrotechnische, Fabrik GmbH & Co.
Theresienstrasse 8, Postfach 13 20, D-7100 Heilbronn, West Germany,
Tel: (07131) 617-0, Telex: 728771
beyerbroadcast
Circle (100) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
139
The BDB features user support groups for Commodore and
computer users, but any computer with a modem and
communications software can access the database via a local
number. Support groups for Apple and TRS-80 users will be
implemented in the future.
IBM
Abekas Video receives monitor award
A special Monitor Award for excellence in engineering
achievement has been presented to Abekas Video Systems,
Foster City, CA, for the manufacture and design of the A62
digital disk recorder. The recipient choice of the special
award for engineering achievement rests with the chief
engineers of Videotape Production Association full member
facilities.
Agfa -Gevaert expands
The magnetic tape division of Agfa -Gevaert has expanded
its technical laboratory at the Teterboro, NJ, facility. The lab
has expanded its capability to do full-range, in-depth evaluations of 1/2-, 3/4- and 1 -inch videotape. It also has expanded its
capabilities for evaluating mechanical and electroacoustical
properties of audiotape by updating its lab equipment.
Harris signs contracts
Harris Broadcast Microwave, Soquel, CA, has signed a contract to supply DALSAT, Plano, TX, with satellite microwave
radio uplink equipment. Harris will supply 25 Ku-band video
exciters. Delivery of the units begins this month with subsequent shipments over the next several months.
Harris also has signed a contract to supply Hunan, China
television with a province -wide TV program distribution
system. Built around the FV8F IF heterodyne microwave
radio, the system consists of nine hops covering several hundred miles. It has two outbound channels and one return
channel.
Harris has announced a contract award by TV station
WITF, Harrisburg, PA, to supply a Microstar 23 system. WITF,
an educational station, purchased the system as part of its instructional TV fixed service distribution system.
Quantel delivers standards converter
Satin, an all -digital broadcast quality standards converter
from Quantel, Palo Alto, CA, is in full-scale commercial production and has been scheduled for delivery to its first United
States buyer. The first unit ordered has been delivered to
Tele-Cine in London.
Anchor Audio purchases ROH product line
Anchor Audio, Torrance, CA, has announced the purchase
of the ROH product line. The ROH operation will be moved
from Atlanta to Anchor Audio's West Coast facility. ROH has
manufactured intercom systems, audio distribution networks
and audio line monitors for the broadcast and industrial
market during the past 18 years.
Moseley and IMS form agreement
Moseley Associates, Goleta, CA, has announced an exclusive license agreement with Integrated Media Systems, San
Carlos, CA. Moseley will manufacture and market the IMS
range of smart audio switchers, analog-digital-analog con-
verters and some industrial switchers.
New Class A
Winner
$
How can
Grass Valley Group
sync so low?
By
designing the SPG Gate Array,
our new integrated circuit, we use
fewer parts and less support circuitry.
And that means reduced maintenance
and higher performance
at an
-
unbelievable price.
SC/H Phase will never be a problem
-
it's always correct.
with the 9505
And you can add to its capability with
an optional test signal generator and
source ID.
The 9505 is only one of our landmark 9500 Series Sync Generators.
Grass Valley Group
A
TEKTRONIX COMPANY
STRENGTH YOU CAN RELY ON
The Grass Valley Group, Inc.,® P.O. Box 1114, Grass Valley, CA 95945 (916) 273.8421 OFFICES: New York (201) 845-7988;
District of Columbia (301) 622-6313; Atlanta (404) 493-1255; Chicago (219) 264-0931; Minneapolis (612) 483-2594;
Dallas/Fort Worth (817) 483-7447; Los Angeles (818) 999-2303; San Francisco (415) 968-6680.
Circle (101) on Reply Card
140
Broadcast Engineering September 1986
www.americanradiohistory.com
Continental's Type 814B 4.3 kW FM
Transmitter uses the Type 802A Exciter to
deliver a crisp, clean signal.
With an output of 4,300 watts, it has plenty
of power reserve for Class A operation on a 2 bay antenna system. Its solid-state except for
one 4CX3500A Tetrode in the final amplifier.
A built-in harmonic filter is just one of many
outstanding operating benefits. Fora
brochure, call (214) 381-7161. Continental
Electronics, a Division of Varian Assoc., Inc.
PO Box 270879 Dallas, Texas 75227.
Transmitters Ito 50 kW AM and to 60 kW FM, FM antennas.
studio & RF equipment. ©1986 Continental Electronics/6213
CA7a t_rL LN t A t
EL.e.4 4 0- i w
t
a DIVISION OF VARIAN
Circle (102) on Reply Card
arian
Auditronics acquires subsidiary
Auditronics has expanded its product base with the acquisition of Tapecaster. The Tapecaster manufacturing operation
has moved to Memphis, to a facility adjacent to Auditronics
headquarters. The division was acquired in April 1985.
Apogee Electronics changes address
Apogee Electronics has moved to 1517 20th St., Santa
Monica, CA 90404. The telephone number is 213-828-1930.
formed on an equal share basis. Willi Studer is chairman of
the board and Pieter Berkhout from Philips is the managing
director.
Bogner supplies antennas
Bogner Broadcast Equipment, Westbury, NY, has supplied
high -power antennas for channel 21 in Mobile, AL, and channel 33 in Pensacola, FL.
MBI Broadcast Systems receives contract
MB! Broadcast Systems, Brighton, England, has been
Ampex broadens facility capabilities
Ampex Magnetic Tape Division, Redwood City, CA, has unveiled a 6-inch tape-coating line at its Opelika, AL,
manufacturing center. Line 9 is specifically designed for the
development of new products previously done at Ampex's
Redwood City headquarters office. In addition to tape production, the line will allow the Opelika facility to develop products to meet digital, video and instrumentation product needs.
Lake Systems expands operation
Lake Systems, Newton, MA, is expanding and consolidating
its operation to renovated property at 287 Grove St., Newton,
MA 02160.
Philips and Studer sign agreement
Philips, Netherlands, and Studer Revox, Switzerland, have
signed a joint venture agreement for research and development of CD-related professional studio systems. Each company holds a 50% interest in the Studer and Philips CD
Systems AG in Regensdorf, Switzerland. The management is
awarded the contract to design, supply and install Iceland's
first independent commercial radio station.
The State Broadcast Service's Channel One has MBI studios
for its national news service and for local news opt -outs in
Reykjavik, Keflavik and Akureyri. Channel Two is equipped
with MBI mixers and other equipment. Sjonvarp, Icelandic
Television, has two Syncon mixers made by MBI's sister company, Allen and Heath Brenell, and modified by MBI.
Matsushita forms new division
Matsushita Electric Corporation of America, Secaucus, NJ,
has established the Panasonic Broadcast Systems Company,
dedicated to sales, service and development of broadcast
systems led by the MII recording broadcast format. The company consists of two main divisions. One is dedicated to sales
and marketing and the other to service and engineering,
which includes product development. Sales and service locations will include New York City, Atlanta, Dallas, Chicago and
Los Angeles.
:r.»»1
Ask for our
FREE CATALOG
OF
&
PR
ESSIONAL
RECORDING
UPLICATING SUPPLIES
e
Blank-Loaded
AUDIO CASSETTES
TAPE
CASSETTES
from MAXELL
AMPEX FUJI 3M
BASF AGFA TDK
ACZESSORIES
from NORTRONICS
3M BASF
EDITALL
Swnchcran Connectors
Canare Microphone Cable
Connecvonics Cable
Telex Cassette Copiers
Signature Prod Moot Lnrary
Polyline
mpty
REELS & BOXES
NAB BROADCAST
CARTRIDGES
Polyline Corp.
123 Rand
Rd.
Des Plaines, IL 60016
(31232913-53130
Circle (103) on Reply Card
How can you get a
free 9500 Series
Timing Conversion
Slide Rule?
Grass Valley Group
P.O. Box 1114, Department 9500
Grass Valley, CA 95945
Just drop us a note on your business card or letterhead, telling us what
type of facility you work in, what sync
generator is currently in use there,
Grass Valley G roupp
\
and how long you've had your current
STRENGTH YOU CAN RELY ON
equipment. Return it to:
and we'll send you your FREE
Timing Conversion Slide Rule!
.
A
TEKTRONIX Ct i111'.1\
-
/¡,
The Grass Valley Group, Inc.,® P.O. Box 1114, Grass Valley, CA 95945 (916) 273-8421 OFFICES: New York (201) 845-7988;
District of Columbia (301) 622-6313; Atlanta (404) 493-1255; Chicago (219) 264-0931; Minneapolis (612) 483-2594;
Dallas/Fort Worth (817) 483-7447: Los Angeles (818) 999-2305: San Francisco (415) 968-6680
Circle (104) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
141
¡New products
Off-line station
The Television Systems Division of Robert Bosch GmbH is
offering an off-line modeling station to extend the capacity of
its FGS 4000 computer graphics system. The system allows a
graphic designer to create various 2-D and 3-D objects for the
choreography of animation sequences. The objects developed
at the off-line station are transferred to the FGS-4000 via an
Ethernet bus interface for final processing.
I
padded nylon Cordura. Features include a deep fold-away
visor that shades the screen and a fold-up adjustable incline
pedestal that allows the monitor to be positioned on the
ground or table at any angle. There is a pocket for batteries
and ventilator flaps. Leather handles and shoulder straps are
provided.
Circle (354) on Reply Card
Music microphones
Circle (350) on Reply Card
Production console, recorders
Fostex Corporation of America has introduced the following products:
The 16-track production console features switchable phantom powering for each mic input, automation updates, in -line
monitoring, continuously variable parametric EQ from 60Hz
to 1kHz and from 400Hz to 6kHz, and two auxiliary sends
and a 3 -position selector.
The E series of recorders are microprocessor-controlled and
feature gapless punch -out, a synchronizer port, built-in Dolby
C noise reduction, built-in 2 -position autolocator, real time
counter, auto stop and auto play and an FET amplifier.
Circle (351) on Reply Card
Mixer
Audio Services Corporation has announced the ASCMX4S-2 mixer. It features RF filtering, 2 -second turn -on,
headphone monitor with 10dB boost, 4-step OdB, 10dB, 20dB
and 50dB input pads, internal battery pack powering, 8dB increase in headroom and a gain structure that allows 10dB
more dynamic range at the channel faders.
Circle (352) on Reply Card
Editing system
Soundmaster International has introduced the integrated
editing system incorporating Syncro. The system is controlled
by the IBM PC-based Soundmaster software. Syncro communicates with the host computer via its 5MHz data bus.
Modular construction facilitates rapid field expansion to 16 or
more units. Each Syncro contains an 8088 and 8087
microprocessor and on-board RAM. Features include
variable -speed lock, programmable closures for external
device tripping and simultaneous synchronization of all international time codes.
Electro -Voice has announced the N/D series of music
microphones:
*The N/D757 is a supercardioid mic with a 25Hz to 22,000Hz
frequency response, - 50dB sensitivity and 144dB range.
The N/D457 is a hypercardioid mic with a 25Hz to 21,000Hz
frequency response, - 50dB sensitivity and 144dB range.
The N/D357 is a supercardioid mic with a 25Hz to 20,000Hz
frequency response, - 53dB sensitivity and 141dB range.
*The N/D257 is a cardioid mic with a 35Hz to 19,000Hz frequency response, - 53dB sensitivity and 141dB range.
The N/D408 is a supercardioid mic with a 30Hz to 22,000Hz
frequency response, -50dB sensitivity and 144dB range.
The N/D308 is a cardioid mic with a 40Hz to 20,000Hz frequency response, -53dB sensitivity and 141dB range.
Circle (355) on Reply Card
Frame grabber
Artronics has introduced the 1024 Image -Grabber high resolution 1,024 x 1,024 line frame -grabbing system. It is
designed for configuration with the Presentation Graphics
Producer system.
Circle (356) on Reply Card
Circle (353) on Reply Card
Digital audio delay line and reverb software
Monitor cases
Porta -Brace has introduced a line of cases for portable
monitors. The model No. MO 22U for the JVC 22U and the
model No. MO 8020 for Sony PVM 8020 are constructed of
142
Klark-Teknik has introduced the following products:
*The DN716 digital delay line offers 16 -bit linear A/D and
D/A converters with state-of-the-art noise and distortion per-
Broadcast Engineering September 1986
www.americanradiohistory.com
Is
your patch cord system ancient history compared with the rest of your equipment?
Moseley's Smart Switcher 256 brings you up to date with the performance
you've come to expect from us and the features your facility needs.
Flexibility
Clarity
Whether you're looking for in -room or in -plant audio
switching, the Smart Switcher is just your size, with
configurations starting from 8 x 8 to route your signal
from anywhere, to anywhere.
What good is the most accurate router if the audio
quality is sacrificed? The same transparency found in
Moseley STLs is built into the Smart Switcher, so your
program arrives at its destination as clean as it began,
with virtually no signal degradation.
Control
Choose your command point: front panel (remoteable
up to 1000 feet), CRT, X -Y controller, or your own personal
bring your switching system up to speed, contact
Moseley Marketing or your authorized Moseley distributor.
computer you can even write your own software for
custom applications.
111
-
To
Castilian Drive Goleta, CA 93117
(805) 968-9621
Reliability
The last thing you want to do after a power-down is
re-enter your set-ups that's why non-volatile memory
preset is standard on the Smart Switcher, backed up by
a redundant power supply for added dependability.
-
Telex 658-448
A Flow General Company
Circle (105) on Reply Card
www.americanradiohistory.com
Moseley
be precisely synchronized to the program. For video subtitling or open captions, the system supports the Chyron VP-1
character generator. English and French alphabets are included in the system.
formance at 20Hz to 20kHz bandwidth. The system has a
dynamic range greater than 90dB and has three outputs and
features front -panel delay settings, control functions lockout
switch, and is microprocessor -controlled with built-in autodiagnostic service routines.
*New No. 2 software for the DN780 digital reverb system includes a full range of reverb styles with low coloration and
wide stereo image, while maintaining mono compatibility.
Circle (359) on Reply Card
Power conditioner
Circle (357) on Reply Card
Production vehicle
Shook Electronic Enterprises has introduced a mobile TV
production vehicle. It is 31 feet long and 8 feet, 9 inches tall
and features all of the electronic equipment for C-band
satellite uplink transmission. It is wired for primary input
power switchable from delta to wye input for use with United
States or European power standards. It is equipped with an
on -board 40kW generator and 5m fold -up dish.
Circle (358) on Reply Card
Closed -captioning software
The Caption Center has announced the CC Writer software
system suitable for all forms of closed captioning and video
subtitling. The system runs on standard IBM PC hardware and
addresses off -the -shelf video equipment. The system combines complete text-editing capabilities with features for
manipulating videotape time code. The resulting captions can
MIR
.
.
COMPONENT SWITCHER $10,715.
NOW AVAILABLE WITH 7 COMPONENT INPUTS
WON
.""-.I
.0 0 mi
.
ä-
.
-
FULL CONTROL FROM EDITOR KEYBOARD
HANDLES BOTH COMPONENT AND ENCODED
SIGNALS
FADE TO BLACK
COLORIZER
RGB CHROMA KEYER
32 PATTERNS
A
O'
PATTERN MODULATOR
COLORED BORDERS
OPTIONS
O O
A
C
B
C
lilt
a'Mt
;II»
Encoded to component decoder
component to RGB translator
400 Event Storage Registers
(100 Sequences)
Serial or parallel Editor control
Second Chroma keyer
7209 Programmable controller
7209 CONTROLS ENTIRE SWITCHER including positioner, colorizer,
of all stored controls during programmed transitions.
CROSSPOINT LATCH CORP.
95 PROGRESS STREET
Country Code
Circle (106) on Reply Card
144
Broadcast Engineering
borders etc., providing smooth transitions
September 1986
www.americanradiohistory.com
1
UNION, N.J. 07083
TELEX 132850
(201) 688-1510
ULÙtsted
Topaz has introduced the ESCORT computer-grade ferroresonant power conditioner. Available from 70VA to 2kVA, the
conditioner corrects voltage fluctuations as large as + 15%
and -35% of nominal line voltage to between +3% and
- 6% of nominal in only two cycles of line frequency. The
conditioner features ultra-isolator noise suppression, provides
up to 126dB of common -mode noise attenuation and up to
60dB of normal -mode noise attenuation.
Circle (360) on Reply Card
Scrim hangers
FREE
CATALOG
Winsted Matchmaker Systems
Big, full color catalog includes complete
descriptions, pricing and ordering information on:
Video Consoles
Editing Consoles
Production Consoles
Dubbing Racks
Equipment Cabinets
Micro Computer Stations
Computer Graphic & Newsroom Consoles
Tape & Film Storage Systems
Winsted Matchmaker Systems... the Perfect Match
for all professional Video Equipment
THE WINSTED CORPORATION
* * * GSA APPROVED * * *
9801 James Circle
Call for your nearest dealer
Phone Toll Free
Minneapolis, MN 55431
i
(800) 447-2257
TELEX: 510-601 -0887
Circle (107) on Reply Card
A SIGHT
FOR SORE
EARS.
rer 4:: 9-.
p
\ lini!
4
1
;A-/
5
/
`---'-----
Nalpak Video Sales has introduced the Scrimpak. It comes
in three sizes molded from crosslinkable polyethylene and
hangs from the adjusting handles of a light stand. The SP -5
holds scrims/gel frames from 5 inches to 7.25 inches, the SP -8
holds scrims from 5 inches to 10 inches, and the SP -12 holds
scrims from 12 inches to 13.5 inches.
Circle (381) on Reply Card
A -V
If ears could talk, they'd scream for SONEX.
distribution equipment
Omicron Video has introduced the following products:
The model 273 component video distribution amplifier has
±3dB of independent manual gain control and ± 1dB of VCA.
The control voltage may be applied to the three amplifiers
from a front-end mounted potentiometer or through a
remote -control port connector. The tracking error is less than
±0.1dB over the VCA control range. Features include selfpowered modules and loop-through input and eight outputs
and BNC connectors.
The model 220 dc -powered video DA has a power input of
+ 11.5V to + 17V. Features include loop-through one input/eight or six outputs, transparent performance and low
power drain.
The only patented acoustic foam with a
specially sculptured anechoic design can
replace traditional studio materials for a
fraction of the cost. SONEX absorbs sound,
ontrols reverb, eliminates stray reflections, and kills standing waves.
hat's left is true sound. Your ears know. Listen to them. Simple to
pply and economical to buy, SONEX blends with almost any decor
nd looks clean, sharp, professional. Call or write us for all the tacts
nd prices.
ONEX is manufactured by
llbruck and distributed
xclusively to the pro sound
sdustry by Alpha Audio.
Olphaeudio©
2049 West Broad Street
Richmond, Virginia 23220
(804) 358-3852
Acoustic Products for the Audio Industry
Circle (108) on Reply Card
September 1986 Broadcast Engineering 14t
www.americanradiohistory.com
The model 280 dc -powered audio DA has a power input of
+ 17V. Features include balanced one input/balanced eight or six outputs, transformer-coupled outputs and low power drain.
The model 470 dc -powered A-V distribution system has
one video DA, one audio DA and one 5 x 1 AFV switcher. The
system operates from the power input of dc + 11.5V to 17V.
Features include front -panel accessible, transparent performance, momentary push-button switches with LED indicator.
The model 501 preset -take 10 x 1 video switcher accepts a
take command to flip-flop program and preset bus selection to
increase program flexibility of digital effects. It features vertical interval switching.
The model 551 preset -take 10 x 1 component video switch er accepts a take command to flip-flop program and preset
bus selection to increase program flexibility of digital effects.
+ 11.5V to
sorb terrestrial -based microwave signals. Specifically formulated tuned microwave absorbing materials are designed
to react with and suppress off -axis interference currents.
Circle (384) on Reply Card
Studio monitor
Circle (362) on Reply Card
Multisubcarrier
Racon has announced the addition of a multisubcarrier to
its Micropass line of 23GHz microwave communications products. The multisubcarrier allows users to use two duplex sub carriers in their microwave bypass telecommunications. The
multisubcarrier can transmit multiple streams of voice and
data in conjunction with video without the need for telephone
lines or cables.
Circle (363) on Reply Card
C -band
earth -station antenna
Miralite has introduced the Miralite T1 antenna. It is a 3.7meter C-band earth -station antenna system designed to ab-
to 5000 messages/second
.adcast Engineering
No central processor, no central failure point
September 1986
www.americanradiohistory.com
SMITE interface
DeltaLab, the Pro Audio Division of Analog & Digital
Systems, has introduced the M1 field studio monitor. It is a
2 -way acoustic suspension model that employs a 1 -inch soft
dome tweeter of polyester fibers, and a narrow magnetic
voice coil gap. The monitor also features a protection circuit
that is triggered by thermal or electrical overload.
Circle (365) on Reply Card
Master control
3M Broadcasting and Related Products Division has introduced the 324 master control on-air switcher that can be
used as a stand-alone master control. It provides 32 audiovideo inputs, four assignable inputs with alphanumeric
readouts and full audio over and under capability. Features
include full analog VU meter with digital peak indicators, four
programmable user -definable transitions, a backup system,
eight audio inputs with auto cart start, A -V auto transition,
three video buses, split A -V for all inputs, manual fader, two
matte generators and a machine control interface.
Circle (366) on Reply Card
Adaptive/interactive software
Lake Systems has announced the latest repackagings of La Kart adaptive interactive software. It will demonstrate three
new solutions to automation needs with the applicationsidentifying names of Broadcaster, Multicaster and Compiler.
Each solution is a proprietary software program resident on
an industry -standard floppy disk. Loading any one of them into the La -Kart operations control center's 68k microcomputer
transforms it into a dedicated automation system with functions identified by the related descriptor.
Circle (367) on Reply Card
Dubbing console
The Winsted Corporation has announced a compact dubbing console. It will accommodate either 1/2-inch or 3/4 -inch
frontloading VCRs. It can hold up to eight VCRs and their
electronics.
Circle (368) on Reply Card
i
Get on the bus...
iu ñLA
äf
Utah Scientific's new DYNABUSTM is the
ideal medium for current and future in plant data communications.
Licensing inquiries from other manufacturers invited. Call 800/453-8782
Toll Free.
BUS/NESS
SERVI G E
(vS
L./Tf9H SC/E/7T/F/C,
r
DYNATECH Broadcast Group
1685 West 2200 South, Salt Lake City, Utah 84119
Phone: (800) 453-8782 Toll Free or (801) 973-6840 TLX 269-916
Super rugged tap -off buffers data, automatically disconnects failed devices
Complete diagnostics
Circle (125) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
151
Don't miss it:
The first annual SBE
National Convention
and
Broadcast Engineering
Conference
Plan now to attend the working engineer's
convention. View the latest ir broadcast
equipment from leading manufacturers.
Attend technical sessions-organized by
John Battison-that answer the on-the-job
needs of radio and TV engineers.
The SBE National Convention an
Broadcast Engineering Conference, the
must -attend event this F a .
bF
!
A.J. e
Convention Center
St. Louis
October 14,15,16
BRODCST
enG neeRr
CONFERENCE
NATIONAL CONVENTION
For exhibitor information cire e (500) on RepIly Card
For atterdee registration informat an circle (600) on Reply Card
www.americanradiohistory.com
Time saver. I
Fiber-optic twin channel
ITT Cannon has introduced the fiber-optic twin channel
product line. It is a lightweight fiber-optic interconnection
system and consists of duplex plugs, simplex plugs, adapters
for duplex -to -simplex and duplex -to-duplex connections and
a device receptacle for PCB or bulkhead applications. The
line features a patented jewel ferrule alignment system, a
keyed mating interface and an operating temperature range
of
-40°C to
,.000000.0000000000000000.0
.,00000.000000000000000000
+ 85°C.
Circle (369) on Reply Card
Visit
Audio -processing product
Kahn Communications has announced the Good n Loud
audio -processing product. The unit is a patented device for
providing + 125% modulation without rough distorted clipping sounds. The system produces a wave that is free of odd
harmonic distortion and also reduces even -order harmonic
distortion. It provides increased modulation by expanding the
entire positive -going modulation rather than clipping the
negative-going modulation.
Circle (370) on Reply Card
Voice processor with mic pre -amp
Symetrix has introduced the 528 voice processor. LED
metering indicates interactive dynamics processor gain
reduction, de -esser activity and output level. Features include
mic pre -amp, compressor/limiter, downward expander, parametric equalizer and de -esser. The downward expander prevents pumping, reduces noise from cart machine solenoids
and paper rattling.
Circle (371) on Reply Card
Nothing Comes
Remotely Close
-
VHF & UHF Units
Watts
Direct FM
Front Panel Metering &
Indicators
Built-in AC Supply
12VDC Input or "Battery
Backup"
19" Rack Mt. - Cabinets
Available
FCC Type Accepted. Parts
2-75
MIN
e
IN
74, 90
SCT500 RPU Transmitter
The Spectrum SCR500 & SCT500 are a series of
high performance broadcast quality RPU Re-
ceivers and Transmitters. They incorporate the
latest advances in solid state technology
brought about by Spectrum's more than a decade
of experience in the two way radio field. These rugged units use the highest quality components &
construction for high reliability in either fixed or
mobile applications.
-
RX FEATURES
VHF & UHF Units
High Sensitivity & Selectivity
High Rejection of IMs &
strong local signals
4 IF Bandwidths Available
Very Low Distortion
Full Panel Meterin
Built-in AC Supply
Many Advanced Features
laga
and 513, SBE
There's no need to spend your valuable engineering time wiring patch
panels. Gentner Engineering's audio patch panels are meticulously hand wired to your specifications, with fast delivery.
Not sure of your specifications? We have more than 200 standard
configurations. Call Dave or Elaine for assistance or information.
GENTNER
The
ENGINEERING COMPANY, INC.
Clear
Choice.
540 West 3560 South
Salt Lake City, Utah 84115
(801) 268-1117
Circle (109) on Reply Card
STOP GROUND -LOOP HUM!
1
Will ELIMINATE HUM and
other INTERFERENCE in
Video Lines caused by differences in Ground Potential.
For Color and Black and White.
FLAT-DC to 6.5 MHz.
No Low-Freq or Hi-Freq. Roll -off.
No Differential Phase Distortion.
No Differential Gain Distortion.
No Envelope Delay.
Passive Device - Failure Free -Low Price.
Small Compact Package 4" x 4" x 2-1/4".
ELIMINATES HUM
AND INTERFERENCE:
IN STUDIO
Between Buildings
On long runs in Buildings
Between Studio and Transmitter
On Incoming Telco circuits
On Outgoing Telco circuits
IN FIELD
Betw. Remote Truck and Telco
Betw. Remote Truck and Microwave
For Intertruck Hookup
For VTR Units
For Monitoring_Lines
SCR500M RPU RECEIVER
SPECTRUM COMMUNICATIONS CORP.
Call or Write for Details. Data Sheets
1055 W. Germantown Pk.
Dept BE
19403
Booths
426,
COIL...HSC
TX FEATURES
orloomosurnou
us in
VIDEO HUM STOP
SPECTRUM RPU LINKS
evrr,-....
I
(215) 631-1710
&
Prices
Norristown, PA
Telex: 846-211
Circle (110) on Reply Card
Available on
trial
10 day tree
rim
AUDIO -VIDEO ENGINEERING COMPANY
65 Nancy Blvd., Merrick, N.Y. 11566
Tel. (516) 546-4239
Circle (111) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
153
vs
PCN
1406
AV DAs and editing software
SERlEs
THROl,lCiá#
35 W
AT NEC,
WE REALLY KNOW
OUR V's AND U's
A worldwide leader ought to know how
to put state-of-the-art television transmitter technology to work. That's why NEC
transmitters are installed in over 1400
locations all over the globe. NEC's full line
of VHF and UHF transmitters feature
high performance exciters, a remarkable
30% reduction in exciter parts (meaning
a 50% improvement in MTBF 30,000
hours). 100% solid state to 10 kW (UHF/
VHF); only one tube to 35 kW (VHF),
broad power output ranges and a design
that accepts stereo without modification. For transmitter technology that's sure
to stimulate your imagination, look to a
-
-
leader. NEC.
NEC
Grass Valley Group has introduced the following products:
The 8510R remote gain video DA allows local, remote or
summed control of both video (±6dB) and chroma (±4dB)
when mounted in the model 8500T2R tray. Front -panel selections include control mode, the gain choices and equalization
for up to 500 feet of Belden 8281 or equivalent cable.
The 8552R remote gain audio DA provides switch selectable gain ranges from + 10dB to +30dB, in three steps.
The V3.0 software for the GVG and ISC editing systems
features 4-level event highlighting, emphasized critical status
and error, increased number of displayed EDL lines, faster list
QUICK RELEASE
BETACAM ADAPTER
fromIlVinten
A PROVEN DESIGN
FOR USE WITH
SONY BETACAM
True quick release
mini wedge system
IS Easily installed
Totally rigid
Optimum balance on pan
and tilt heads provided
through the use of
alternate 3/8" and 1/4"
mounting holes
Complete with combination
male/female wedge adapter
IMAGINE WHAT WE'LL DO FOR YOU
For true state of the art design,
manufactured by
ceCOMPUTERS AND COMMUNICATIONS
VINTEN EQUIPMENT INC.
NEC AMERICA, INC., Broadcast Equipment Division
1255 Michael Drive, Wood Dale, IL 60191
Toll free 1-800-323-6656In Illinois 312-860-7600
39 Cain Drive, Plainview, New York 11803-4492
Telephone: 516/694-8963 Telex: 640470 Fax: 516-752-1289
Branch Office: 8115-B Clybourn Avenue, Sun Valley, California 91351-4022
Telephone: 818/767-0306
Telex: 182686
Circle (112) on Reply Card
Circle (126) on Reply Card
154
Broadcast Engineering
September 1986
www.americanradiohistory.com
and screen display and user-friendly menu. Control of the
Abekas A-62, the Panasonic MII format VTRs, Lynx/timeline
interfaces and Lexicon has been added.
A
Circle (372) on Reply Card
BROADCAST
OPERATIONS
SECRET
YOUR
HARDWARE
Ku -band downlink and uplink filters
HASN'T
TOLD YOU:
Microwave Filter Company has introduced the following
products:
The bandpass filter 5282-2 that passes the commercial Ku band downlink (11.7GHz to 12.2GHz) and suppresses the Ku -
SHOULDER CASE FOR
IKEGAMI HL95
ready and able to be automated, now...
if it has channels that can write and read
SMPTE/EBU time code, or even if it's only
remote -controllable via GPI commands. You
simply integrate it into a customized LA -KART
Broadcast Automation System.
LA -KART Systems are different... assembled
from broadcast-standard hardware, and
run by field -proven "Al" software developed
for Adaptive Interactive control of on -air
Ws
operations. And both software and hardware
are adaptable and expandable to meet your
future operations needs. Add your choice of
new CAV and digital video and audio cassette
tape and disk formats only when you're ready.
The biggest expense to equip your station for
automated operation is already behind you.
Now's the time to finish the job; call on
So
LA -KART to run it.
now you know your hardware's secret:
Rs ALREADY READY
81. The All -The -Time Case. Put this
unique case on your camera/recorder-and
leave it on-for full-time protection
against bumps, scrapes, dust, rain, snow,
heat and cold-on your shoulder and off,
on a tripod and off, in fair weather and
foul. For Sony Beta-Cam and Ikegami
HL95, call for information.
FOR AUTOMATING.
LA-KART'
The Adaptive Interactive Automation Solution
The Systems Company
K&H Products, Ltd.
Box 246
North Bennington
Vermont 05257
802-442-8171
5
Chapel Street, Newton, MA 02160 (617) 244-6881
Circle (69) on Reply Card
Circle (113) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
155
Wipe
reco
material
band uplink (14GHz to 14.5GHz) and commercial mobile communications band (10.55GHz to 10.68GHz). Uplink and
mobile band suppression is 70dB nominal. VSWR and insertion loss are 1.25:1 maximum and 0.5dB. The 6 -inch unit is
designed in WR -75 waveguide with cover flanges.
The bandpass filter 5283-2 passes the commercial Ku -band
uplink (14GHz to 14.5GHz) and suppresses the Ku -band
downlink (11.7GHz to 12.2GHz). VSWR and insertion loss are
1.25:1 maximum and 0.75dB maximum. The 5 -inch unit is
designed in WR -75 waveguide with cover flanges.
Circle (373) on Reply Card
Compact routing switchers
Utah Scientific has introduced a series of compact routing
switchers. The CAA/CAV-20/ 10, available in audio/audio or
audio/video 10 -input x 10-output or 20 -input x 10 -output configurations. Features include up to four separately addressable levels, two coax party lines, plus two RS-232/422
ports, and sync tip clamping on video inputs and outputs.
Circle (374) on Reply Card
Aperture response test charts
Porta -Pattern has added the RCA P200 and P300 apertureresponse test charts to its range of test images. These charts
were developed to permit accurate evaluation of TV camera tube resolution and also for use in setting up the tube
assembly for minimal effect of spot ellipticity. Both charts are
based on a technique of using non -vertical lines in a special
Model 1400
One-inch video
tape eraser
Model 105
resolution -measuring pattern.
Audio and
computer tape
or disc eraser
Model 270
Video cassette
tape eraser
Hundreds of studios and
production facilities nationwide
save on tape cost without
sacrificing recording integrity
by using a Garner magnetic
tape eraser. Garner
outperforms all others in depth
of erasure, speed of operation,
dependability and durability.
The complete line includes
erasers for 1" high-coercivity
video tape, video cassettes,
audio tape and
computer media.
TALK TO US!
THE PATCH BAY SOURCE.
YOUR SOURCE.
WHETHER IT'S standard wired audio panels,
custom -wired audio panels, panels with jacks, panels without jacks, patch cords, telephone jacks,
Polysand, patch cord holders-whether it's one or
a thousand you need-we've got everything immediately available to help you get your installation
or expansion completed ON TIME!
Write or phone for information on Audio -Line
Write or call our toll -free
number for a free brochure.
Toll -Free 800-228-0275
industries
products.
audio accessoriesE v
audioIine
4800 N. 48th St., Lincoln, NE 68504, (402) 464-5911
TELEX 438068
AUDIO ACCESSORIES, INC., MILL ST.,MARLOW, NH 03456
603-446-3335
Circle (114) on Reply Card
156
Broadcast Engineering
Circle (115) on Reply Card
September 1986
www.americanradiohistory.com
Chart P200 facilitates camera -tube beam focus adjustment
for minimum astigmatism and allows accurate performance
measurement of the tubes of the highest resolution with virtual independence of video amplifier bandwidth.
Chart P300 allows accurate specification of the camera -tube
tub© LcflIkKfr
resolving power using the modulation transfer function
theory.
Circle (375) on Reply Card
Audio mixing system
Leddicons®
......
4)(,,.v®E.
are in
every type
1" camera
1111111111111118
that uses
WC.
lead oxide
tubes.
Orion Research has announced the AMU series TV audio
mixing system. The system is available in eight to 32 stereo
inputs. Auxiliary sends, monitors, submasters and masters
Here's why...
Anti microphony.
A double damped mesh...
only in EEV Leddicons.
TV STEREO
BTSC AURAL MODULATION MONITORS
High Resolution Greens for
sharper, crisper pictures
at all light levels...and
less aperture correction.
Leddicon's light bias technique
significantly improves lag
in individual channels.
BELAR
TVM-100 AURAL BASEBAND DEMODULATOR/MONITOR
Mono/Stereo/Multi-Charnel Capable
Digital Peak Frequency Deviation Display
Split -Sound and Quasi -Parallel
Detection Modes
Extended Reds with close
tolerance i,ifrared cut-off
filters for the best "red"
reproduction.
omoti 011
all
tupes
Pr
Sp clal m art d , nmm
etallS.
25m
for d
our
call t
..
..
On
43f
8
t
pires 9
Find out how 1" Leddicons can
ove
image.
Call
wroeur
Registered Trademark of
EEV Lead Oxide Cam era Tubes
3Ól86)
.
At EEV... your image
is our business.
flaLAP
TVM-200 BTSC STEREO DECODER/MONITOR
Full -Time Composite and L &R Metering Two Auto -Ranging
Meters for Full Stereo Signal Test and Measurement II Genuine
dbx^ Decoder Card Line Level Stereo Audio Outputs
B E LA R ELECTRONICS LABORATORY, INC.
119
EEV, INC.
4 Westchester Plaza. Elmsford, NY
10523,914-592-6050
EEV CANADA, LTD.. Rexdale, Ontario. 416-745-9494
LANCASTER AVENUE, DEVON, PA 19333
l
(215) 687-5550
Where Accuracy Counts
.
Count on Belar
Circle (134) on Reply Card
Circle (117) on Reply Card
September 1986
www.americanradiohistory.com
Broadcast Engineering
157
also are stereo. The system has analog rack-mounted electronics separated from an all -digital control panel by a serial
cable. Automated features include ReMem, a recall memory
system and SoftMap, an input -to -fader routing system. The
system also includes a CRT output.
editor provides 250 event memory, list management with ripple, list input and output, disk control, variable speed search
and jog, built-in interfaces for -inch, 3/ -inch or 1/2 -inch formats, automatic assembly sequential or checkerboard, and
pulse readers or automatic transition control with 10
preprogrammed commands.
1
Circle (378) on Reply Card
Circle (378) on Reply Card
Noise-control product
Alpha Audio has introduced the SONEX 1, a flame resistant, noise -control product. The product is made of a
porous acoustic melamine material that meets class 1 requirements for both flame spread and smoke density, yet retains the anechoic wedge properties for noise reduction. The
product will be sold in 2 -inch -thick 2'x4' uncoated panels. It
comes in four sheets to a box.
Satellite video source identifier
QS! Systems has introduced the Star -2400 satellite video
source identifier. It will display 24 characters consisting of the
10 -digit telephone point -of -contact, transmitter license
number, user alphanumerics and a 2 -digit operator number.
The telephone and operator numbers are front -panel pro-
grammable with the remaining 12 characters programmed
via internal DIP switches using the ASCII 64 -character menu.
Circle (377) on Reply Card
Circle (379) on Reply Card
Computerized electronic video editor
Video slide image system/video camera lifter
United Media has announced the expandable Comm -ette
A/B roll computerized electronic video editor. The editor
allows the user to upgrade progressively from control track to
SMPTE/EBU time code, and from two to three machines including time -code generator and full switcher control. The
Interactive Motion Control has introduced the following:
The video slide image system provides precision movement
of magnified images from 35mm slides or 2'/4 -inch transparencies. The zoom lens is computer -controlled and the
THE IDEAL WAY TO SWITCH MONITOR FEEDS
Audio Follow Video
Balanced Stereo Audio
IN A PROBLEM -FREE, ECONOMICAL MANNER.
Rack Mount 19' x 1-3/4
BNC Connectors - Video
Multiple Edge -Board Audio Connector
10 x 1 PASSIVE SWITCHER
Centralab Switches - Interlocking
Bifurcated Silver Contracts
Legend Strip
.....a+o.e..,.a..ti..-....-.-a..
Unswitched Video Terminated - 75 OHMS
LOW COST
Unswitched Audio Easily Terminated
No Signal Loss
No Signal Degradation
Cross Talk Better Than -60db
Model AFV - 10
No Power Required
.roc 9eie,
Simple Construction - Long Life
Light Weight - Under 5 lbs.
48647 Twelve Mlle Road Novi, Michigan 48050 (313) 349-7910
$295.00
H. M. DYER E(ect
Circle (118) on Reply Card
32pg Catalog
FREE
THE ULTIMATE TIMING TOOLS
FOR THE TELEVISION INDUSTRY
&
50 Audio/Video Applic.
PNO SLIPP, EO,
PHON
MIN.
Ae4
TRANS,S, ACH,
Stereo ï Mono Pert
VIDEO LEVEL AUTOMATICALLY MAINTAINED AT UNITY!
a
i4
VIDEO,
4.0,TAPE,
INE, OSC
9-I,, 2 -out, 12 -Im 4 -out, 18-In:4-oul
TV Audio & Rend Prod Coneolea
W-41,46:
Audio DIM Ample.
VIeP
OPAMP LABS INC
1033
ASD 2000
N
(213) 934-3566
Sycamore Av LOS ANGELES CA, 90038
Circle (120) on Reply Card
25-2125 ns
Infinite control throughout entire range via switches and fine
trim. Ideal for remotes, matte timing. Also available in
20-1120 ns range. Rackmountable - 2 units in 1 RU frame.
PRECISION MAGNETIC
TEST TAPES
©TD
ESD 500
40-540 ns
timing new installations. A must for every
Microprocessor control: front panel pushbutton or
remote, UP/DOWN, FAST/SLOW, 1 ns resolution. Precise delay
indicated on LED readout. Also rackmountable.
The ideal unit for
lab.
broadcast video systems ltd.
1050 McNicoll Avenue, Agincourt, Ontario M1W 2L8
Telephone: (416) 497-1020 Telex: 065-25329
Otion
Standard Tape Laboratory, Inc.
26120 Eden Landing Road #5, Hayward, CA94545
(415) 786-3546
Circle (121) on Reply Card
396 SHIPPING ANY SIZE ORDER
1-800-245-6000
O
A
OUP.
64
CON.
19
369
929
199
CON -90
109
tir
20.
89
399
AVY60
19.99
MOM
SONY
TIM
4.99
T-30
T.
T.
1999
158
Broadcast Engineering
September 1986
www.americanradiohistory.com
6.49
1,20
749
FUJI
CREDIT
ILCA.130
6C6,2090
16
11M
ON PO
3.51,T60
836
361-T120
0.49
6088
1916
c
48 HP
M.6 8'.30-500
SHIPPING
412 282-8621
O
Circle (119) on Reply Card
105
1.39
COLOR FKUS
(V
Circle (131) on Reply Card
system can be mounted on an optical rail or video animation
stand. System features include projector, light source, positioning stage and a Canon lens. Up to 16 axes can be controlled.
The computer-controlled video camera lifter features stability, speed and portability. The lifter provides up/down movement of a camera mounted on a nodal -point head with
pan/tilt/roll. Components include a 9-foot -tall column and a
3 -foot extension arm. The rotational axes provide +360° of
rotation at up to 45° per second. A Canon lens is included.
OUR FM
MONITOR
DESERVES
A SECOND
Circle (380) on Reply Card
GLANCE.
Microwave spectrum analyzer
BUT IT DOESN'T NEED
IT.
Engineers look twice when they first see
our 691 Stereo and SCA Monitor. But when
they start to use it, they find the 691's
meters are easily tracked in a single glance.
Like everything else about the 691, its
measurement displays are very well
thought out.
A color-coded system ties together the
associated displays, switches, and jacks for
a particular function or test. Select your test
by pushing a color -coded button and
simply read the results on all of the indicators. It's as easy as it sounds.
Anritsu America has introduced a series of microwave spectrum analyzers that can measure from 10kHz to 140GHz.
Designated as the MS710C/D/E/F, the four analyzers have
been updated to include 300Hz and 100Hz resolution bandwidth, a 100dB dynamic range and improved stability. Up to
nine measurement setups can be stored in memory. The
series have direct plotting capability and are fully GPIB programmable.
Circle (381) on Reply Card
Other benefits of the 691 include over 40
proof-of -performance and signal quality
measurements. Add a scope and use the
691 as a spectrum analyzer ... or get a
vector display of LIR phasing. Perform a
Bessel -Null calibration in minutes. Measure
clipped composite accurately and quickly.
The 691 can now be optionally ordered to
measure two SCAB. There are many other
features ... write or call for complete
information.
Oscilloscopes
Tektronix has introduced the following products:
The 2245 and 2246 general-purpose oscilloscopes feature
4-channel, 100MHz bandwidth, 2mV sensitivity and a 2% vertical and horizontal accuracy. The scopes also have auto-level
trigger, A and B readout intensity controls, and a low -noise
vertical system.
The 2400 series of portable oscilloscopes-the 150MHz
2445A, the 250MHz 2455A and the 2465A-feature automation, single-button setup, save/recall setup memory, setup sequencing, setup transfers without a controller and increased
bandwidth. The scopes feature four channels with dual delaying time bases and on -screen measurement cursors.
QEI Corporation
P.O. Box D
One Airport Drive
Williamstown, NJ 08094 (609) 728-2020
!
Call Toll Free (800-334-9154)
Circle (382) on Reply Card
Mounting mixers and consoles
Soundtracs has introduced the following products:
range of 19 -inch rack-mounting mixers with modular con-
A
struction.
The CP6800 24 -track console equipped with an on-board
computer system automating the routing and patching of the
desk against SMPTE time code. It features a monitor, disc
storage, SMPTE reader and an 8-way events controller.
Circle (383) on Reply Card
I
=:4)))I
Circle (122) on Reply Card
September
www.americanradiohistory.com
1986
Broadcast Engineering
159
News
Continued from page 4
both the compatibility of equipment and
ease of program interchange. The
group's documents will define the colorimetry, optical/electronic conversion,
scanning parameters, blanking waveforms and other details of the high definition TV signal. Other documents
will define studio level interfaces for this
signal, in both analog and digital terms.
The timing reference signal for the
HDTV studio also will be defined.
Keith Field of the Canadian Broadcasting Corporation is chairman of the
ad hoc group.
the Society's Board of Governors.
Baylor University, Pasadena City College, Rochester Institute of Technology,
Sam Houston State University and the
University of Southern California at Los
Angeles are the other educational institutions that are officially represented in the
SMPTE with student chapters.
grams. Its objective will be to promote
the development of the Japanese visual
software industry and to provide a forum
for international information and business exchange.
More than 50,000 visitors from around
the world are expected to attend. A wide
range of participants at the fair will include film and video distributors, audio-
visual equipment
Software Fair
will be in Japan
The International Audio Visual SoftFair Promotion Council, in
ware
SMPTE adds
student chapter
Manhattan Community College in New
York has formed a student chapter of the
Society of Motion Picture and Television
Engineers (SMPTE). The college, a part
of the City University of New York, had
its application approved at a meeting of
0*
WATCH"
MONITOR PROTECTS
SENSITIVE
AUDIO-VISUAL
EQUIPMENT
NEWS
cooperation with the Japanese Ministry
of International Trade and Industry, will
present a preview of tomorrow's audiovisual age at the International Audio
Visual Software Fair '86, Oct. 24 to 29, at
the Osaka Castle Hall and the Hotel New
Otani in Osaka, Japan.
The fair covers a vast field of visual
software from videotapes and videodiscs
to computer graphics and videotext pro-
C DfÉ
manufacturers,
technology developers and representatives from TV stations, advertising
agencies and production houses.
A -V
IEEE sponsors 36th
broadcast symposium
The 36th annual Fall Broadcast Symposium sponsored by the IEEE Broadcast
Technology Society will be held on Sept.
18 and 19, at the Washington Hotel,
Washington, DC. A broad range of
technical subjects will be covered.
I
CORNELL-
IRlA
DUBILIER
,-7%re
4
,
:r-))ll
MICROPHONE
/ I
Mica Capacitors
The Tube
turns RED
if equipment
is abused!
WARNING
Handle Veth Care
.INCONSPICUOUS
Mlle
.WIDE FREQ. RESPONSE
.VERY LOW RUBBING NOISE
'Red Onocates
Exceaarveknpact
i -as
CONTROL EQUIPMENT ABUSE.
Enforce proper handling
techniques.
Eliminate re -shootings.
Reduce repair cost.
.RUGGED - IMPROVED CABLE
VACUUM
CAPACITORS
.NEGATIVE & POSITIVE BIAS
'.BOUNDARY LAYER ADAPTORS
.HARD WIRE & WIRELESS MIC
'.PHANTOM OR BATTERY POWERED
.DETACHABLE 250 OHM POWER SUPPLY
JENNINGS
LOW PROFILE - IDEAL HIDDEN MIC
CONNECTORS FOR ALL WIRELESS MICS
.10 DIFFERENT MICROPHONE HOLDERS
Protect expensive equipment.
Call Toll Free: 1-800-527-9497
or write today.
IIIII1MEDIA
RECOVERY, INC.
305 Wisconsin Avenue
Oceanside, California 92054
(619) 722-6162
1435 Round Table Drive, Dallas, Texas 75247
214-630-9625
Circle (123) on Reply Card
160
Broadcast Engineering
.4 COLORS-BLACK/GRAY/TAN(FLESH)/WHITE
SURCOM ASSOCIATES, INC.
Circle (124) on Reply Card
September 1986
www.americanradiohistory.com
i
358-7895
PO Box 821 Nyack,N.Y.10960
(914)
Circle (133) on Reply Card
lAd index!
Page
Number
AVS
97
Abekas Video Systems
Abekas Video Systems
ADC Telecommunications,
Inc.
ADM Technology, Inc.
AEG Corp
7
71
132
6
48
Page
Advertiser
Hotline
201/767-1000
415/571-1711
415/571-1711
Number
JVC Company of America
K & H Products Ltd.
Lake Systems Company
Leitch Video of America, Inc.
Lerro Electrical Corp
121
14
115
72
13
36
97
153
111
612/893-3010
313/524-2100
201/722-9800
804/358-3852
514/735-4105
800/227-1613
415/367-2911
415/367-2911
415/367-2911
305/595-1144
303/224-2248
603/446-3335
201/671-8668
800/231-7350
215/443-0330
216/686-2600
516/546-4239
157
138-139
134
100
216/687-5550
516/935-8000
94
714/898-7224
Ltd
128
158
C.O.A.R.0
Camera Mart, Inc
91
Canon USA Inc., Broadcast Lens ...80-81
Canon USA Inc., Broadcast Lens ....129
112
Cipher Digital Corp.
Circuit Research Labs, Inc
13
Comprehensive Video
46
Comsat General Corporation
68-69
Continental Electronics Mfg.
Co., Div. of Varian
140
Crosspoint Latch Corp.
144
114
Crown International
29
Datatek, Inc.
100
Datum Inc
92
119
95
56
64
78
9
30
46
416/697-1020
518/672-7202
212/757-6977
516/488-6700
516/488-6700
301/695-0200
800/535-7648
201/767-7990
202/863-6909
Polaroid Corp.
Polyline Corp
Potomac Instruments
102
106
80
15
63
Sachtler (USA)
Dielectric Communications
Digital Video Systems Div.
Dubner Computer Systems
Dynair Electronics Inc.
67
43
214/381.7161
201/688-1510
219/294.8000
201/654-8100
714/533-6333
800/341-9678
416/299-6888
201/592-6500
619/263-7711
914/592-6050
212/930-7500
800/446-7878
416/335-3700
800/228-0275
801/268-1117
801/268.1117
916/273-8412
916/273-8421
916/273-8421
Alpha Audio
Amber Electro Design Inc
Amperex Electronic Corp.
Ampex Corp. (AVSD)
Ampex Corp. (MTD)
Ampex Corp. (MTD)
Angenieux Corp. of America
Arrakis Systems, Inc
Audio Accessories
Audio Kinetics Ltd
Audio Precision
Audio Technologies Inc.
Audio-Technica U.S., Inc.
Audio -Video Engineering Co.
Belar Electronics Laboratory
Inc
Beyer Dynamic Inc
88-89
IFC
37
Reader
Service
Number
149
78
87
107
102-103
47
110
27
156
125
26
98
62
1
21
108
16
61
73
71
29
49
Broadcast Cartridge Service
Inc
128
Broadcast Video Systems
E E V,
Inc.
Eastman Kodak Co
Eventide
Evertz Microsystems Ltd.
Garner Industries
Gentner Engineering Co., Inc
Gentner RF Products Div.
Graham -Patten Systems Inc.
Grass Valley Group, Inc.
Grass Valley Group, Inc.
Gray Communications
Consultants, Inc.
H.M. Dyer Electronics, Inc.
Hannay Reels
Hewlett Packard
Hitachi Denshi America Ltd
Howe Audio
ICM Video
IGM Communications
Ikegami Electronics Inc.
Ikegami Electronics Inc
Ikegami Electronics Inc.
Intl. Tapetronics Corp./3M
JBL Inc.
JBL Inc
Jensen Transformers, Inc
95
66
9
111
7
70
38
156
153
94
30
66
54
140
101
141
104
131
86
118
87
68
108-109
158
124
99
3
82
84
117
45
126-127
101
33
43
93
76
Marconi Communications
Systems Ltd
MCL, Inc
Media Recovery, Inc.
Microdyne Corp
Microtime, Inc.
Midwest Communications Corp.
Miller Fluid Heads (USA) Inc.
Moseley Associates Inc
NEC America Inc
NEC America Inc
Neve Inc.
Odetics, Inc.
Opamp Labs Inc.
Orban Associates Inc
Orban Associates Inc
P.T.S
I
4
57
59
83
28
90
70
19
26
65
52
912/883-2121
313/349-7910
518/797-3791
800/556.1234
800/645-7510
800/525-7520
405/232-5808
206/733-4567
201/368-9171
201/368-9171
201/368-9171
800/447-0414
818/893-8411
818/893-8411
213/876-0059
39
44
160
48
83
1
67
143
61
154
53
65
158
17
64
105
Pacific Recorders and Engineering ...21
118
Paco Electronics
55
Panasonic
34-35
Panasonic
Ramsa/Panasonic
Rapp Associates Inc
Richardson Electronics Inc.
Rohde & Schwarz Sales
Sencore
Sescom, Inc
Sharp Electronics Corp
Sharp Electronics Corp
Shure Brothers Inc.
Siemens Neve
Solid State Logic
Solutec Ltd
Sony Corp. of America (A/V
-
& Pro Aud.)
Sony Corp. of America
(Broadcast)
Spectrum Communications
Standard Tape Laboratory,
Inc
Studer Revox America Inc.
Surcom Associates Inc
Tape World
Tascam Division TEAC Corp.
of America
Telcom Research
Telemetrics Inc.
Thomson Video Equipment
Thomson-CSF Broadcast
Thomson-CSF/DTE
UREI
Utah Scientific Inc.
Valley People
Vid Video
Videotek, Inc.
Vinten Equipment Inc.
Ward -Beck Systems Ltd.
Wheatstone Broadcast Group
Winsted Corp
69
5
32
23
27
123
31
83
3
45
105
39
126
34
42
120
10
41
89
12
84
35
20
98
103
800/582.5825
802/442-9118
617/244-6881
804/424-7290
215/223-8200
800/328-1684
312/354-4350
214/630-9265
904/687-4633
203/242-4242
800/543-1584
818/841-6262
806/968-9621
800/323-6656
800/323-6656
203/744-6230
800/243-2001
213/934-3566
800/227-4498
800/227-4498
201/529-1550
619/438-3911
213/747-6540
201/348-7336
38
122
60
37
133
40
914/358-7895
800/323-1770
79
123
49
128
75
77
55
88
11
53
56-57
66
113
24-25
153
18
93
51
53
8
34
44
516/328-1100
516/231-0033
800/843-3338
800/634-3457
201/265.5548
201/265-5548
312/866-2553
203/744-6230
212/315.1111
514/521-5464
79
110
215/631-1710
121
17
160
158
124
131
415/786-3546
615/254-5651
619/722-6162
412/283.8621
119
116
135
115
73
40-41
93
150.151
136
42
137
154
BC
85
82
130
213/726-0303
416/681-2450
201/423-0347
158
31
IBC
149
September 1986
www.americanradiohistory.com
113
58
159
85
59
160
63
141
QEI
QEI
11
Advertiser
Hotline
800/225-1618
312/297-0955
301/589-2662
800/334-9154
800/334-9154
132-133
Co. (USA) Inc.
75
117
74
47
22
114
109
157
3M
19
155
155
5
15
50-51
Reader
Service
Number
81
50
24
65
125
96
25
99
112
2
107
203/965-7000
818/893-8411
800/453-8782
615/383-4737
800/826-2035
602/997-7523
516/694.8963
416/438-6550
203/393.0887
800/328-2962
Broadcast Engineering
161
Professional services
VIR JAMES P.C.
CONSULTING ENGINEERS
Applications and Field Engineering
STEIGER, HURRAY &
ASSOCIATES INC.
Computerized Frequency Surveys
CONSULTING ENGINEER SERVICES
-80219
3137 W. Kentucky Ave.
(303) 937-1900
6816 Westview Drive
Cleveland, OH 44141
(216) 526-7187
DENVER, COLORADO
Member AFCCE & NAB
FCC ON-LINE DATABASE
datawopld
Allocation. Terrain Studies
AM
FM
LPTV
TV
ITFS
P.O. Box 30730
Bethesda. MD 20814
1-800-368-5754
(301) 652-8822
TELECOMMUNICATIONS
R. CIAPURA
PRESIDENT
(6191
695-2429
LAWRENCE L. MORTON
ASSOCIATES
21671 SUPERIOR LANE
LAKE FOREST, CALIFORNIA 92630
nuc0r4.111v,c,no+1
LAWRENCE L. MORTON, E.E.
AM
TV
FM
Associates, Inc.
CONSULTING ENGINEERS
206 North Bergan
Peoria, Illinois 61604
(309) 673-7511
APPLICATIONS FIELD ENGINEERING
ANTENNA BROADBANDING FOR AM STEREO
Aüg 10ü@
Broadcasting and Telecommunications
Consultants
BROADCASTING CONSULTANTS
AND ENGINEERS
Contact:
KENNETH W. HOEHN
23400 Michigan Avenue
Dearborn, MI 48124
g.Telatechgnc,.
(313) 562-6873
ATT: CHIEF ENGINEERS
m,t.n.nc
LUNAR VIDEO LTD.
6eoaJmst oiJ.o
FAST TURNAROUND ON ENO, EFP, EDIT
SYSTEMS, MONITORS, TEST EQUIP. SONY, JVC,
PANASONIC, TEKTRONIX UPS Er AIR FREIGHT.
PU/DEL DAILY.
CALL
COLLECT
-
138 E. 28th St, NYC
(212)888-4802
Advertising rates in Classified Section are $1.50 per
word, each insertion, and must be accompanied by
payment to insure publication.
Each initial or abbreviation counts a full word.
Minimum classified charge, $35.00.
For ads on which replies are sent to us for forwarding (blind ads), there is an additional charge of $35.00
per Insertion, to cover department number, processing
of replies, and mailing costs.
Classified columns are not open to advertising of
any products regularly produced by manufacturers
unless used and no longer owned by the manufacturer
or distributor.
162
Broadcast Engineering
UUUULJçI:J@@
STATION DESIGN AND SERVICE
ELECTRONIC PRODUCT DESIGN
Edward A. Schober, P.E.
402 Tenth Avenue,
Haddon Heights,
BLAIR BENSON
Engineering Consultant
TV Systems Design and Operation
23 Park Lane
Norwalk, CT 06854
(202) 293-7742
203-838-9049
Robert J. Nissen
T & G OPTICS, INC.
71-01 INGRAM STREET
FOREST HILLS, NY 11375
COMPLETE REPAIR SERVICE FOR COLOR TELEVISION
CAMERA BEAMSPLITTER OPTICS, LENSES, COATINGS,
MULTIPLEXER MIRRORS. FILTERS AND PROJECTORS:
WRITE OR CALL GERALD PINCUS (718) 544-8156 twenty (our hour service with pleasure.
SELLMEYER & KRAMER, INC.
CONSULTING ENGINEERS
J.S. Sellmeyer, P.E., S.M. Kramer, P.E.
AM FM TV MDS ITFS LPTV CAN
APPLICATIONS
FIELD ENGINEERING
P.O. Box 841 Mckinney, TX 75069
(214) 542-2056
Consultation Services
Power Conditioning Grounding
Over 40 years experience, work guaranteed
Lightning
-
Roy Carpenter
P
es,oent
Lightning Eliminators and Consultants
13007 Lakeland Rd.. Santa Fe Springs, CA 906)4
12131 9466886 T W X 910-5861381
IClassifiedi
TRAINING
ELECTRONICS DEGREE by correspondence. Earn
Associate, then Bachelor's. NHSC accredited. Free
catalog. Write Grantham College of Engineering,
Dept. EE-5, 10570 Humbolt St., Los Alamitos, CA
8-82-tf n
90720.
FCC GENERAL RADIOTELEPHONE operators license
through cassette recorded lessons at home plus one
week seminar in Boston, Washington, Detroit or
Philadelphia. Our twentieth year teaching FCC license
courses. Bob Johnson Radio License Preparation,
1201 Ninth, Manhattan Beach, Calif. 90266, Telephone
8-81-tfn
(213) 379-4461.
September 1986
www.americanradiohistory.com
NJ 08035
(609) 546-1841
THE NISSEN GROUP, INC.
Communications Technology Consultants
32 Ridge Drive
Port Washington, New York 11050
(516) 944-5477
(714) 859-6015
FCC Applications and Field Engineering
Frequency Searches and Coordination
Tower Erection and Maintenance
Facility Design and Construction
`V'
RADIO CONSULTING ENGINEERS
Member AFCCE
2033 M Street N.W., Suite 600
Washington, D. C. 20036
Dennis
111
&
SMITH and POWSTENKO
TEKNIMAX
11385 FOREST VIEW LN.
SAN DIEGO. CA 92131
D. L. MARKLEY
EVANS ASSOCIATES
CONSULTING TELECOMMUNICATIONS ENGINEERS
AM-FM-TV-CATV-ITFS-LPTV SATELLITE
218 N. Green Bay Road
Thiensville, Wisconsin 53092
Phone: (414) 242-6000 Member AFCCE
ERIC NEIL ANGEVINE, P.E.
consultant in acoustics
specializing in broadcast studio acoustics
910 Lakeridge Drive
Stillwater, OK 74075
405-624-6043
405.372-3949
MEDIA COMMUNICATIONS, INC.
COMPLETE ENOINEERINO NEEDS
Allocations
AM, FM, LPTV
FCC Information
P.O. Box 37732/Shreveport, LA
t
71133-7732
Phone (381) 746-4332
SERVICES
ONE STOP FOR ALL YOUR PROFESSIONAL AUDIO
REQUIREMENTS. Bottom line oriented. F.T.C. Brewer
Company, P.O. Box 8057, Pensacola, Florida 32506.
7-71-tf
TRANSMITTER TUBES REPROCESSED-Save 40 to
50%. 3CX2500, 4CX5000, 4CX15000 and many others.
Write for details. FREELAND PRODUCTS CO., Rt. 7,
Box 628, Covington, LA 70433. (504) 893-1243 or (800)
624-76266.79-tfn
VACUUM TUBE REMANUFACTURING-Save 60%.
Longer life. Better performance. We specialize in
Transmitting Tubes, Vacuum Capacitors, Power
Tubes. All major types. Write or call: FARADEX ELECTRONICS COMPANY, 150 Main Street, Port
Washington, New York 11050, (516) 775.7838.
8-86-61
FOR SALE
EMPLOYMENT OPPORTUNITIES
TELEVISION,-true stereographic NEW! LeaVision tm over/under (not red/blue). Viewers, consulting.
lens rental. Info -SASE. DEMO (VHS/BETA)+ photo +
viewers -$29.95 ' $2 S&H. TVLI-BE, CS3030 Lindenhurst, NY 11757 (516) 957-4393 (212) 245-6119. 9-86-tf n
3-D
RCA COLOR TELECINE SYSTEM, New/unused. To include: TK -66, color camera, TP -66, 16mm telecine projector, TP -7, 35mm slide projector, TP -55B, camera
multiplexer. Write to: P.O. Box 23555-273, San Diego,
CA 92123.
1-86-tfn
SONY BVE 3000: complete edit controller. Excellent
Condition; CMX P interface for MCI ATRS. (415)
841-0601.
9-86-2t
USED-DEMO-NEW
EQUIPMENT-SALE
CAMERAS: Hitachi
SK -91 and SK-81 w/lens from
$5995. RECORDERS '/.": JVC-5550 and JVC-6650 from
TBC's:
For
$1895.
-A, Nova & GML from $4650.
2-D -Digital -Effects: Cel-EFEX-I, EFEX-I1 from $8500.
GML-Proteus $16995. 3-D-Dlgltal-Effects: NEC -E -FLEX
$20000. NEC-Optiflex $30000. MONITORS: NEC,
Panasonic,
Philips, Tektronix from $325.
Leitch, Lenco from $1295.
WAVEFORMMONITORS & VECTORSCOPES:
Viceotek, Tektronix, new from $1595. CHARACTER
GENERATORS: Quanta, Mycrotek from $1795. TIME CODE -EQUIPMENT: Sony, Amtel, Adam -Smith from
$1250. TIME -CODE -SYNCHRONIZER -SYSTEMS:
Adam -Smith from $4995. A/B-ROLL-TIME-CODE-EDITCONTROLLERS: United Media from $6000.
STANDARDS -CONVERTERS: CEL-P156/2 and Quantel
from $9500. MICROPHONES: Beyer, Sennheiser from
$198. TRIPODS W/FLUID-HEADS. Sachtler from $2295.
Ask for detailed list: Inter -Cine -Video-Corporation, Ph.:
312-872-1665, Telex 857192.
9-86-1t
SYNC. -GENERATORS:
BRAND NEW CONRAC MONITOR 5725/C13, $2700.00.
Brand new Wavetek Model 1080 sweep generator
$2,400.00. Brand new Wavetek Model 190 20MHz function generator $750.00. Brand new RCA heads 2 each
431474, $750.00 each - 1 each 431473, $750.00 - Plus
lots of Elmac tubes all new. Contact. AMEX Electronics, 501 New York Avenue, Union City, N.J. 07087.
Telex:132853. Phone (201) 348-3363.
9-86-3t
TEKTRONIX 521 A PAL vectorscope. 19" rack in excellent condition $3500. Hitachi FP4055 color camera,
with 10:1 Fujinon lens $2000. 818-352-6619.
9-86-2t
VIDEO EQUIPMENT Sony 1 inch BVH-1000 VTR no
TBC, hetro board, $15,000, BVH-1100/TBC 2000,
$27,500. BVH-1100/TBC 2000 with Dyn Tracking,
$29,500. Quantel DPE-5000 digital effects system
$18,500. Panasonic time code editing system, AUA -70, NV -9600, NV -9240 'A", $7,500. 2 Hitachi FP -21
Cameras, 2 line enhancer, bat., 10 to 1 zoom, 3,500 ea.
JVC-4700U with TC generator, 2 batteries, $2,900,
Sony Betacam BVW-40 Editor, $23,000. Mr. Gerber
202-546-8900.
9-86-1t
RECONDITIONED MASTER CARTS, completely
cleaned, new pads, new tape, reasonably priced.
SAVE up to 40%, let us clean and reload your cartridges. Catalog. Bob Sims (817) 535-1953. American
Media Services, Box 1953, Fort Worth, TX 76101.
9-86-1t
COPPER! For all your broadcast needs. #10 ground
radials; 2, 4, 6, 8" strap, flyscreen, counter poise mesh.
317-962-8596. Ask for copper sales.
7 -86 -St
WE PLACE
/TV and Video
Engineers
COAST TO COAST
HELP WANTED TECHNICAL: REMOTE ENGINEER
position open on mobile unit. Must have strong tech
maintenance background, Ampex VPR-2Bs, Grass
Valley Switching, Chyron 4100, Ikegami Cameras,
Salary commensurable with experience. Call Ken
Gardner, 317-463-1800, WLFI-TV, Inc., Box 7018,
Lafayette, IN 47903.
9-86-1t
TV MAINTENANCE ENGINEER wanted for main-
[All Levels, But Not Operators]
ALL FEES PAID BY EMPLOYERS
tenance and repair of state of the art broadcast video
equipment and systems. Looking for experienced,
Phone/Resume
minimum of two years of VIDEO MAINTENANCE EXPERIENCE. Salary commensurate with experience. If
interested, please send resume to Personnel-WNYC, 1
Centre St.-32nd Floor, New York, NY 10007. EOE/AA.
responsible and committed person
KEY SYSTEMS
479 Northampton Street
Kingston, PA 18704
with
a
9-86-1t
Phone Alan Kornish at
J
(7171283-1041
JOB HUNTING? The best jobs are on
the line ... MediaLine. We dig up the
freshest television and radio engineering jobs. Subscribe for 6 or 13
weeks to get your pick of broadcast engineer jobs. Learn more.
MANAGER-TV MAINTENANCE wanted to supervise a
maintenance staff of five, assist In design and installation of new facilities, perform appropriate administrative duties and oversee the upkeep of equipment. Must have at least three years of supervisory experience in a management level engineering position
at a TV station or video facility; television
maintenance background with an ability to
troubleshoot to the component level; ability to work
well under pressure; thorough knowledge of state-ofthe-art video equipment. Salary commensurate with
experience. If interested, send resume with salary
history to Personnel-WNYC, 1 Centre St.-32nd Floor,
New York, NY 10007. EOE/AA.
9.86-1t
312-855-6779.
DIRECTOR OF
ENGINEERING
HELP WANTED
ASSISTANT CHIEF ENGINEER: Major market PBS affiliate has opening for A.C.E. Familiarity with studio
and UHF transmitter necessary. Excellent salary, excellent benefits. Chicago residency required. Send
resume to: Columbus Jenkins, Business Operations
Manager, WYCC-TV/Channel 20, 7500 S. Pulaski Rd.,
Chicago, Illinois 60652. City Colleges of Chicago is an
Equal Opportunity Employer.
8-86-3t
MAINTENANCE TECHNICIAN-WXOW TV is seeking
a qualified studio technician. Must have a minimum of
three years experience including U-Matic Tape and
FCC License. Send resume to WXOW TV, P.O. Box
C-4019, La Crosse, Wisconsin 54601 c/o Chief
Engineer.
9-86-1t
OPENING FOR BROADCAST ENGINNERING Supervisor. Responsible for supervision, installation, operation, and overall maintenance and major repair of the
technical systems and facilities. BS or specialized
technical degree with 5-7 years broadcast experience
required. Supervisory experience desired. Equivalent
education or experience accepted in lieu of degree.
Submit application and/or resume to UNM Personnel,
1717 Roma NE, Alburquerque, NM 87131, between
8:00 AM and 4:00 PM weekdays. Mention this ad on
your application and reference requisition #722-A.
AA/EOE.
9-86-11
Leading New York City post production facility seeks Director
of Engineering for administration,
design, and long-term facilities expansion planning. Minimum 5
years video and digital experience
required. Generous salary and
benefits. Send resume to Dept.
670, Broadcast Engineering, P.O.
Box 12901, Overland Park, KS
66212.
VERMONT ETV, MAINTENANCE TECHNICIAN. To
maintain, install, construct and design television
broadcasting equipment in the studio in addition to
monitor signals and products at the studio assuring
FCC compliance. Qualifications: Associate's degree
with concentration in electronics and at least one year
experience In television broadcasting maintenance or
an equivalent combination of education and experience. General radio/telephone operator's license
required. Should be familiar with TK/45 studio camera
setups.
VIDEO SPECIALIST. Experienced master control/production engineer needed at Vermont ETV.
Must be familiar with all stages of master control
operations, as well as 1" editing for production. Three
years appropriate television experience required. Apply to the University of Vermont Employment Office,
237 Waterman Bldg., Burlington, VT 05405. Please include social security number when applying. An Affirmative Action/Equal Opportunity Employer.
9-86-1t
Broadcast equipment sales
WANTED TO BUY
HIGHEST PRICES for 112 Phase Monitors, vacuum
capacitors and clean, one kw or greater powered AM
and FM Transmitters. All duty and transportation paid.
Surplus Equipment Sales, 2 Throncliffe Park Dr., Unit
28, Toronto, Canada M4H 1 H2, 416-421-5631.
3-86-tfn
WANTED: WW -Il German and Japanese radio equipment. Unused US Navy and Signal Corps radio equipment before 1943. Pre -1923 radio equipment and
tubes. August J. Link, Surcom Associates Inc., 305
Wisconsin Ave., Oceanside, CA 92054, (619) 722-6162.
7-86-tf
WANTED: RCA FR 35-B TV projector, also, 3 tube
Vidicon camera, also, Magnatech 4000 series film
sound reproducer. Call Richard Lees, (213) 464-4351.
8-86-2t
Circuit Research Labs, Inc. seeks an energetic individual to
join its sales team in Tempe, Arizona.
Applicants should be well versed in all phases of radio and
television broadcast operations, have excellent
communication skills and previous experience selling to
broadcasters.
If you are interested in employment with our dynamic
company, please send your resume in confidence to:
AIM
4111
W
IMr>.
IM IBM
111131MB
Min
Ray Updike
Director of Marketing and Sales
Circuit Research Labs, Inc.
2522 West Geneva Drive
Tempe, Arizona 85282
September 1986
www.americanradiohistory.com
Broadcast Engineering
163
MAINTENANCE ENGINEER. Top Ten Market, PBS
Station: Excellent opportunity. Applicant should have
a minimum three years maintenance experience. SBE
Certification, FCC General Class; College degree
preferred. Good benefits, competitive salary.
Resumes to: Gilda Jones, KERA TV/FM, 3000 Harry
Hines Blvd., Dallas, Texas 75201.
9.86.4t
CHIEF ENGINEER: KFYR-TV in Bismark, North Dakota
is seeking a chief engineer. Should have RCA
transmitter -Harris microwave and ACR experience.
Applicants with chief or assistant chief status and
minimum of 5 years TV experience preferred.
Associate degree helpful. Reply to: General ManagerKFYR-TV, Box 1738, Bismark, N.D. 58502. Salary
negotiable. Resume required. KFYR-TV is an Equal
Opportunity Employer.
9-86-1t
Product Design Engineer
Orban is hiring electronic engineers to design new products for both our pro audio and broadcast markets.
Ideal candidates should have:
-MSEE or equivalent with specific expertise in audio
signal processing, filter design, modern analog circuit
techniques, and high -quality audio circuit design.
-Imaginative mind that can help define new products
for professional audio and broadcast applications.
VIDEO MAINTENANCE ENGINEER. TV production
company in Dallas seeking staff video maintenance
engineer w/minimum 2 years experience with 1 and 2
inch VTR's, computerized editors, video switcher and
telecine systems. Excellent working conditions; full
benefits package. Send resume to: Gene Carter, Director Operations, Southwest Teleproductions, 2649
Tarna Drive, Dallas, Tx 75229-2222.
94361t
-Critical listening skills.
-Familiarity with microprocessor
and other digital detechniques.
sign
Five years experience in a manufacturing environment, coupled with an understanding of production
and cost restraints on product design.
RADIO GUY RESISTORS by Lopp Insulator, LeRoy,
New York, $95 each, case of 6-$70 each. David
Ogletree, Route 1, Box 43A, Livingston, Tennessee
38570.615.823.1644.
9-86-1t
POST PRODUCTION FACILITY has immediate need
for engineer with experience in system design and
maintenance of state-of-the-art teleproduction equipment. Ability to communicate with management a
must. Exceptional salary, benefits and advancement
available to the right applicant. Resume and
references to: L. Tompkins, 8600 Westpark, #110,
Houston, Texas 77063.
9-86-1t
Please send a copy of your resume to:
STUDIO AND UHF TRANSMITTER: maintenance
technician. Must have UHF transmitter maintenance
experience. Contact Ken Preston, KSEE (209) 2372424, P.O. Box 24000, Fresno, CA 93779. EOE M/F.
oben
8-86-21
WPAT JOB OPPORTUNITY: WPAT HAS AN OPENING
FOR THE FOLLOWING POSITION: Technical Supervisor. New York station has opening for highly
qualified technical supervisor. Maintenance experience required for all phases of broadcasting. Contact Kenneth Stout, WPAT AM/FM, 1396 Broad Street,
Clifton, New Jersey 07013. 201-345-9300. AN EQUAL
OPPORTUNITY EMPLOYER.
8-86-2t
Manager
Orban Associates Inc.
645 Bryant Street
J. Hodge, Personnel
San Francisco, CA 94107
(415) 957-1063
/Advertising sales offices
CHICAGO, ILLINOIS
NORWOOD, AUSTRALIA
Tom Nilsen
Phone: (312) 887-0677
(312) 887-0684
Hastwell, Williamson, Rouse Pty. Ltd.
P.O. Box 419
Norwood 5067, Australia
Phone: 332-3322
Telex: AA87113
15
Spinning Wheel Rd.
Ste 430
Hinsdale, IL 60521
LONDON, ENGLAND
Joe Concert
Phone: (212) 682-6630
Nicholas McGeachin
Suite 460, Southbank House.
Black Prince Rd.
London SEI 7SJ
Telex: 295555LSPG
Telephones: 01-582-7522
01-587-1578
SANTA MONICA, CALIFORNIA
Herbert A. Schiff
TOKYO, JAPAN
Haruki Hirayama
Phone (213) 393-9285
Jason Perlman
Phone (213) 458-9987
Schiff & Associates
EMS, Inc.
1317 Fifth St., Ste 202
Santa Monica, CA 90401
Innervision Productions Incorporated,
Sagami Bldg., 4-2-21, Shinjuku
Shinjuku-ku, Tokyo 160, Japan
(03) 350-5666
Cable: EMSINCPERIUD
Telex: 2322520 EMSINCJ
a
leading
production/post-production facility in St. Louis
seeking
NEW YORK, NEW YORK
(212) 682-6631
Josh Gordon
Phone: (212) 687.5076
(212) 687-5077
630 Third Ave., Eighth Floor
New York, NY 10017
Maintenance
Engineer
a
is
Maintenance Engineer.
You will have direct interaction with operations
personnel and your responsibilities will include
preventive maintenance, repairs and installation of
video and audio equipment. In addition, you may
occasionally be involved in assisting a production
crew.
To qualify, you must be a self -motivated, people oriented type with 4 years' production facility
experience and knowledge of Ampex and Sony
VCR's and VTR's; Ikegami cameras; Ampex, GVG
and Utah switchers and editors; Chyrons; Bosch
FGS; Otari, Dolby, Sony, A -K and other audio
equipment and various monitors and distribution
equipment. Computer literacy, construction and
operations experience are desirable.
We can offer a very competitive salary, excellent
a fast paced and stimulating work
environment. For consideration, submit your
benefits and
MITERTEC
©1986. All
rights reserved.
resume to: Personnel Department; Busch Creative
Services; 5240 Oakland; St. Louis, MO 63110.
Equal Opportunity Employer.
INNER
164
Broadcast Engineering
September 1986
www.americanradiohistory.com
AO
Multiple Choice:
What do you need in an audio console?
Every application is different; what are your
requirements? Should the input section be stereo or mono, mic or line? What kind of outputs
and subgrouping do you need? Is a matrix mix
important? Do you require mix -minus capabilities? What about metering, timers, tape
remotes, mainframes, future expansion?
A-500 Radio
On -Air
WHEATSTONE consoles give you all the choices. Our sales
engineers listen to your requirements, then work with you
and plan your console from the first module to the last VU
meter. The result is custom -configured equipment built
specifically to your needs.
The truth is, there's only one choice when specifying broadcast equipment: QUALITY. There's simply no room in
broadcast for cutting corners; when you're on -the -air the
phrase "Time is Money" takes on real meaning.
SP -5 Stereo
Production
TV-80 Television Master
So whatever your application, stereo or multitrack production, television master control,
on -air, video edit, or mobile installation, consult WHEATSTONE.
/,'//////////f/111I lI I
.,
I
..,...,.
I i
11ï1..
QUALITY
There's
Better
...
No
Choice.
3224 Melti-Track
Wheoútone Corporation
5 Collins Road, Bethany, CT 06525 (203-393-0887)
Circle (2) on Reply Card
www.americanradiohistory.com
Ward -Beck's all -new D8212 Audio Distribution
System is totally transparent! Absolutely nothing
else on the market today can compare for
precision, performance, packaging or price!
Check these features:
Twelve high-performance modular DAs
each with 8 outputs.
Dual switch -mode power supplies.
31/2" rack mounting frame.
Unique hinged/quick-release front panel.
Gold-plated terminals throughout.
Integral typewriter designation strip.
Unmatched overall performance specifications.
Renowned Ward-Beck Reliability and Quality.
e Priced right.
First by Design.
The Ward -Beck D8212 System
- An Investment in
Quality!
iiImeneetx.
Ward -Beck Syste
Ltd., 841 Progress Avenue, Scarborough, Ontario, Canada M1H 2X4.
www.americanradiohistory.com
Tel: (416)438-6550
Tlx: 065-25399.
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising