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 [email protected] 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 [email protected] 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. 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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:  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. 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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. 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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. 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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. 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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) 18.104.22.168 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. 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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. 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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:[email protected]@ 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.
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