null  User manual
INSTRUCTION MANUAL
- for
Model 1035
WOW & FLUTTER
METER
æ DYNASCAN
ОДНИ CORPORATION
6460 West Cortland Street |
Chicago, Illinois 60635
TABLE OF CONTENTS
Page
TEST INSTRUMENT SAFETY ..........inside front cover
INTRODUCTION ...qeooscsoococscccococococacreccel
FEATURES ..occonccoooococo oo oo ooo ces
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SPECIFICATIONS. ccc cs + © ...e....
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CONTROLS AND INDICATORS......
Front Panel Controls ..........
Rear Panel Facilities .........
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OPERATING INSTRUCTIONS ..e.ooccocococsaoorcere 10
Safety Precautions ......... e.…........ 10
Equipment Protection Precautions................10
Operating Tips .....oorcococaro .. 11
ii
Page
Line Voltage Selection ..................0.0..0. 11
Preparation for Operation. .........0...0......... 11
Wow/Flutter Measurement .........0...0.0000000. 11
Use of Rear Panel Terminals. ...................13
Use as Frequency Counter. ..............0.......13
MAINTENANCE 0 00000000000 0000
Case Removal 0...0000000000000000000000000 19
Fuse Replacement 00000000000000000000000000 15
Adjustments.......oocoscoroscsacerecarereeee 15
Instrument Repair & Calibration Service ...........16
s.............s. 10
WARRANTY SERVICE INSTRUCTIONS ....oosscccaro 18
LIMITED ONE-YEAR WARRANTY ...... inside rear cover
INTRODUCTION
The B & K-Precision Model 1035 Wow & Flutter Meter is a
precision audio test instrument for measuring wow and flutter
of turntables, tape recorders, or other rotating devices. Since
this instrument measures wow and flutter as low as 0.003%, it
is suitable for checking professional equipment as well as
home entertainment products. Six ranges give good resolution
for all values from 0.003% to 10%.
There are four primary standards for wow and flutter
measurement used in the world - JIS (Japan), NAB (U.S.A.),
CCIR (France), and DIN (Germany). This versatile instrument
accomodates all four measurements standards by pushbutton
selection. In addition, line voltage selection is easily changed
to permit operation from 100, 117, 220, or 240 volt 50/60 Hz
ac power. These features make the instrument fully inter-
national.
Wow and flutter is measured by playing a test record or
tape which has been pre-recorded with a continuous 3 kHz
(JIS, NAB, or CCIR) or 3.15 kHz (DIN) tone and feeding the
audio signal into the instrument. Wow and flutter cause
variations of the test tone frequency. The variations are
separated from the test tone and measured. The frequency of
the test tone is displayed on a built-in four-digit frequency
counter and the percentage of wow and flutter is indicated on
a large easy-to-read analog meter.
Flutter causes test tone variations of 6 Hz to 200 Hz,
while wow causes variations under 6 Hz. Filters separate the
wow and flutter components of the signal if desired. Mode
selection permits the user to select measurement of flutter
only, wow only, or wow and flutter combined, either weighted
or unweighted.
The instrument accomodates a wide range of input signal
levels, permitting measurement at nearly any desired point in
the equipment under test. There are two selectable sensitiv-
ities of 0.5-100 mV and 5 mV-30 V. The high sensitivity posi-
tion permits measurement of small signals directly from tape
heads and phono cartridges if desired. The associated level
monitor indicator is a time saving feature for setting up
tests. The indicator lights if the input signal level is adequate
for wow and flutter measurements; no other measurements or
adjustments are required.
Another convenience is the built-in crystal-controlled
oscillators which provide very stable sources of 3 kHz and
3.15 kHz for recording wow and flutter test tapes.
Auxiliary output jacks provide outputs to other instruments
such as oscilloscopes and chart recorders if desired. These
jacks provides a de voltage proportional to rotational speed
error, and both ac and de voltages proportional the wow and
flutter meter reading.
For added versatility, the built-in four-digit frequency
counter may be used independently from wow and flutter
measurements for general measurement of audio frequencies.
The instrument offers selectable crystal controlled or line
frequency (50 or 60 Hz) time base. An overflow indicator
lights for frequencies higher than 9999 Hz,
FEATURES
WIDE MEASUREMENT RANGE
Measures wow and flutter from 0.003% to 10% in 6 ranges.
PRECISION MEASUREMENTS
Measure wow and flutter as low as 0.003%. Suitable for use
with professional type tape recorders and turntables.
HIGH SENSITIVITY
Minimum operating input voltage is as low as 0.5 mV, permit-
ting measurement of wow and flutter directly from a small
output tape head or phono cartridge.
WIDE INPUT LEVEL RANGE
Selectable input level in two steps permits measurement of
inputs from 0.5 mV to 30 V.
FOUR MEASUREMENT STANDARDS
Pushbutton selectable measurement standards makes unit
fully international. Measures rms values (JIS - Japan), mean
values (NAB - U.S.A.) and peak values (CCIR - France and
DIN - Germany).
FOUR MODES
Four pushbutton selectable modes, weighted or unweighted
combination of wow and flutter, wow only, or flutter only.
BUILT-IN WOW & FLUTTER OSCILLATOR
Measures wow and flutter from pre-recorded test record or
tape. Built-in oscillator permits recording of wow and flutter
test tape. Selectable 3 kHz (JIS, NAB, or CCIR) or 3.15 kHz
(DIN) standards.
BUILT-IN FREQUENCY COUNTER
Four digit display indicates wow and flutter test frequency
(approximately 3000 Hz or 3150 Hz). May be switched to
operate as 10 Hz to 9999 Hz frequency counter for measure-
ment of any audio input signal.
AUTOMATIC LEVEL MONITOR
Indicator lights if input signal level is appropriate. No exter-
nal measurement of input level required. In frequency counter
mode, indicator flickers if count exceeds 9999 Hz as overflow
indication.
CRYSTAL OSCILLATOR STABILITY
Internal 3 kHz and 3.15 kHz oscillators and time base for
frequency counter are crystal controlled.
AUXILIARY OUTPUTS
Three auxiliary output jacks provide ac and de output volt-
ages for connecting frequency analyzers such as oscilloscope,
chart recorder, or digital memory scope. AC voltages pro-
portional to wow and flutter; de voltages proportional to
speed error and wow and flutter.
UNIVERSAL LINE VOLTAGE
Operates from 100, 117, 220, or 240 volt 50/60 Hz ac power.
Simple external changeover.
SPECIFICATIONS
WOW & FLUTTER METER SECTION
easuring Center Frequency:
3 kHz +300 Hz (JIS, NAB, CCIR).
3.15 kHz +300 Hz (DIN). |
Input Sensitivity:
Two ranges; 0.5 mV to 100 mV and 5 mV to 30 V.
Wow & Flutter Measurement Range:
5 mV to 30 V Input Sensitivity:
0.003% to 10%, 6 ranges.
0.5 mV to 100 mV Input Sensitivity:
0.01% to 10%, 6 ranges.
Input Impedance:
300 KQ 120%, unbalanced.
Display System:
RMS value (JIS).
Mean value (NAB).
Peak value (CCIR, DIN).
Display Accuracy:
+5% of full scale (at 4 Hz).
Response:
Weighted Characteristic:
In accordance with JIS, NAB, CCIR/DIN
(at 0.2 Hz to 200 Hz).
Wow Characteristic:
0.5 Hz to 6 Hz (-3 dB +1 dB) (JIS/NAB).
0.3 Hz to 6 Hz (-3 dB +1 dB) (CCIR/DIN).
Flutter Characteristic:
6 Hz to 200 Hz (-3 dB +1 dB).
Unweighted Characteristic:
0.5 Hz to 200 Hz (-3 dB 11 dB) (JIS/NAB).
0.3 Hz to 200 Hz (-3 dB +1 dB) (CCIR/DIN).
Roll Off:
JIS/NAB:
Below 0.5 Hz; more than -6 dB/octave.
Above 200 Hz; more than -15 dB/octave.
CCIR/DIN:
Below 0.3 Hz; more than -6 dB/octave.
Above 200 Hz; more than -15 dB/octave.
Maximum Input Voltage:
100 V (de + ac peak).
Input Monitor: |
LEVEL MONITOR indicator lights above input sensitivity
threshold of 0.5 mV or 5 mV.
FREQUENCY COUNTER SECTION
Measuring Frequency Range:
10 Hz to 9999 Hz.
Input level:
100 mV to 30 V rms.
Input Impedance:
300 k2 + 20% (unbalanced).
Counting Capacity:
Decimal system, 4-digit LED memory display.
Reference Time:
Reference Time Frequency:
10.080 MHz (built-in crystal).
AC power frequency (AC line power).
SPECIFICATIONS
FREQUENCY COUNTER SECTION (Continued)
Reference Time Accuracy:
+5 x 1079, 0 to +409 C (built-in crystal).
AC power supply accuracy (AC line power).
Gate Time:
1 second.
Measurement Accuracy:
+(1 digit + reference time accuracy).
Maximum Input Voltage:
100 V (de + ac peak).
Input Monitor:
LEVEL MONITOR indicator lights at more than 100mV of
input (flickers at more than "9999 Hz" to indicate
overrange condition).
OUTPUT TERMINALS
Recording Output Signal (OSC):
Signal Frequency:
3 kHz, 3.15 kHz.
Accuracy:
+5 x 10
Output Voltage:
0.2 Y rms +20% (into open circuit).
Output Impedance:
600 + 20% (unbalanced).
Distortion Factor:
Less than 1% (600 Q terminated).
Drift Output Terminal (DRIFT):
Output voltage:
Approx. 41 V de for each 1% of frequency drift.
Output impedance:
600 9 +20% (unbalanced).
Scope Output Terminal (SCOPE):
Output Voltage:
Approx. 3 V rms at full scale meter reading.
Output Impedance:
600 9 +20% (unbalanced).
Recorder Output Terminal (RECORDER):
Output voltage:
Approx. 1 V de at full scale meter reading.
Output impedance:
600 Ohm +20% (unbalanced).
POWER REQUIREMENTS
Voltage:
AC 100/120/220/240V +10%, 50/60 Hz.
Power Consumption:
Approx. 14 Watts.
MISCELLANEOUS
ting Temperature
0 to +40 9 C.
Dimensions (HxWxD):
Case Dimensions:
5-7/8 x 10-1/4 x 12-1/2" (150 x 260 x 318 mm).
Dimensions Including All Projections:
| 6-5/8 x 10-1/4 x 14-1/2" (170 x 260 x 370 mm).
Weight:
Approx. 11-3/4 1b (5.3 kg).
Accessories Supplied:
Input/Output Cable; dual banana plug to alligator clips.
Detachable AC Power Cord.
Instruction Manual.
Schematic Diagram & Parts List.
CONTROLS AND INDICATORS
FRONT PANEL CONTROLS Refer to Fig. 1.
1.
POWER Switch. Pushbutton ON-OFF switch. Engaged
postion is ON, released postion is OFF. When power is
applied, the FREQUENCY display indicates "0000" (no
input) and serves as a pilot light to show that the in-
strument is operating.
OSCillator Switch. Pushbutton switch selects 3 kHz
(JIS-NAB-CCIR) or 3.15 kHz (DIN) at OSC OUTPUT
terminals. Engaged position selects 3.15 kHz, released
position selects 3 kHz. |
OSC OUTPUT Terminals. Source of 3 kHz or 3.15 kHz
(as selected by OSC switch) sine wave signal for record-
ing wow and flutter test tape. Signal level is 200 mV
rms into open circuit, output impedance is 600 £ distor-
tion is less than 1%.
The INDICATION switches, items 4 thru 7, are mechanic-
ally interlocked so that only one may be engaged at a given
time. Pressing a button releases the previous selection.
4,
de
6.
JIS Switch. Meter will indicate rms value of JIS stand-
ard (Japan).
NAB Switch. Meter will indicate mean value of NAB
standard (U.S. A.).
CCIR Switch. Meter will indicate peak value of CCIR
standard (France).
7. DIN Switch. Meter will indicate peak value of DIN
standard (Germany).
The FUNCTION switches, items 8 thru 11, are mechanical-
ly interlocked so that only one may be engaged at a given
time. Pressing a button releases the previous selection.
8. WTD Switch. Meter will indicate weighted combination
of wow and flutter to selected JIS, NAB, CCIR, or DIN
standard (0.2 Hz to 200 Hz frequency response).
9. WOW Switch. Meter will indicate wow component only
(0.5 Hz to 6 Hz for JIS or NAB, 0.3 Hz to 6 Hz for CCIR
or DIN).
10. FLUTTER Switch. Meter will indicate flutter compon-
ent only (6 Hz to 200 Hz).
11. UNWTD Switch. Meter will indicate unweighted combi-
nation of wow and flutter (0.5 Hz to 200 Hz for JIS or
NAB, 0.3 Hz to 200 Hz for CCIR or DIN).
12. INPUT Terminals. Input terminals for measuring wow
and flutter; also input terminals to frequency counter.
Maximum input voltage is 100 volts de + ac peak, input
impedance is 300 kf.
13. SENSITIVITY Switch. Pushbutton switch selects input
level sensitivity for wow and flutter measurements.
Engaged position is for 5 mV-30 V signal level at INPUT
terminals. Released position is for 0.5 mV-100 mV sig-
nal level at INPUT terminals.
CONTROLS AND INDICATORS
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Fig. 1. Front Panel Controls and Indicators.
6
CONTROLS AND INDICATORS
14.
15.
16.
17.
18.
19.
WOW FLUTTER/FREQ COUNTER Switch. Pushbutton
switch selects mode of measurement. Released position
is for WOW FLUTTER measurements. Engaged position
is for FREQ COUNTER measurements; sensitivity be-
comes 100 mV to 30 V rms at INPUT terminals.
RANGE (%) Pushbutton Switch Assembly. Set of six
interlocked pushbutton switches select meter range of
0.03%, 0.1%, 0.3%, 1%, 3%, or 10% full scale. Use
corresponding 0-3 or 0-10 scale of meter.
LEVEL MONITOR Indicator. In WOW FLUTTER mode,
indicator will light when input signal is of adequate
level (above sensitivity threshold of 0.5 mV or 5 mV,
depending upon SENSITIVITY selection) and correct
frequency (3 kHz +300 Hz or 3.15 kHz +300 Hz, depend-
ing upon INDICATION selection). In FREQ COUNTER
mode, indicator will light when input signal is of ade-
quate level (above 100 mV); indicator will flicker if
frequency exceeds 9999 Hz as an overflow indication.
FREQUENCY (Hz) Display. Four digit LED display
indicates the frequency of wow and flutter test signal
being measured in WOW FLUTTER mode, or frequency
of signal applied to INPUT terminals in FREQ COUNT-
ER mode. Indicates "0000" with no input. The display
always serves as a pilot light to show that the instru-
ment is operating.
Handle.
Meter. Indicates wow and flutter in 9%. Two scales of
0 - 3 and 0 - 10 correspond to meter RANGE selection.
Use 0 - 3 scale for 0.03%, 0.3%, and 3% ranges; use
0 - 10 scale for 0.1%, 1%, and 10% ranges.
20.
Tilt Stand (Refer to Fig. 2). Elevates front of instru-
ment for convenient viewing angle.
о
o
Stand
Fig. 2. Use of Tilt Stand.
REAR PANEL FACILITIES Refer to Fig. 3.
21.
22.
23.
24,
Cord Wrap. Stores power cord when not in use.
Fuse Holder. Use 0.5 A fuse for 100 or 117 VAC, 0.3 A
for 220 or 240 VAC,
Power Cord Receptacle. Connector for detachable
power cord.
Line Voltage Selector. Removable plug may be inserted
four ways to select 100, 117, 220, or 240 V line voltage.
CONTROLS AND INDICATORS
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Fig. 3. Rear Panel Facilities.
CONTROLS AND INDICATORS
25.
26.
27.
28.
GND Terminal Case ground and earth ground via power
cord.
TO SCOPE Terminal Provides ac output voltage pro-
portional to wow and flutter indicated on meter, suit-
able for viewing on oscilloscope. Output voltage is
3 volts at full scale meter deflection, output impedance
is 600 Q
DRIFT Terminal Provides de output voltage propor-
tional to rotational speed error. Output voltage is
+1 volt for +1% speed error.
RECORDER Terminal Provides de output voltage pro-
portional to wow and flutter indicated on meter. Suit-
able for driving chart recorder. Output voltage is 1 volt
for full scale meter deflection, output impedance is
600 &
29.
30.
REFERENCE FREQUENCY Switch. Three-position
slide switch selects reference frequency for frequency
counter as follows:
50 Hz
60 Hz Uses 60 Hz line frequency as reference.
CRYSTAL Uses internal crystal controlled oscillator
as reference.
Fuse Label. Indicates line voltage limits and correct
fuse value for each of 100, 117, 220, and 240 VAC line
voltage.
Uses 50 Hz line frequency as reference.
OPERATING INSTRUCTIONS
SAFETY PRECAUTIONS
1.
WARNING
The following precautions must be observed to prevent
electric shock.
When this instrument is used with equipment that con-
tains high voltage, there is always a certain amount of
danger from electrical shock. The person using the
instrument in such conditions should be a qualified elec-
tronics technician or otherwise trained and qualified to
work in such cirmcumstances. Observe the TEST IN-
STRUMENT SAFETY recommendations listed on the
inside front cover of this manual.
The ground wire of the 3-wire ac power plug places the
chassis and case of the instrument at earth ground. Use
only a 3-wire outlet, and do not attempt to defeat the
ground wire connection to float the instrument.
To test "hot chassis" equipment, always use an isolation
transfomer between the ac outlet and the equipment
under test
Always connect a cable from the GND terminal on the
rear panel of this instrument to the chassis or common
of the equipment under test.
10
Do not operate this instrument with the case removed
unless you are a qualified instrument service technician.
High voltage is present when the unit is operating with
the case removed.
EQUIPMENT PROTECTION PRECAUTIONS
CAUTION
The following precautions will help avoid damage to the
instrument. |
. Excessive voltage applied to the INPUT jacks may dam-
age the instrument. The maximum rating of the input is
100 V (de + ac peak).
Never apply external voltage to output jacks.
Do not attempt to float the chassis and case reference
of the instrument to a voltage point in the equipment
under test; to do so may damage the instrument or the
equipment under test.
The Line Voltage Selector must be set to match the ac
line voltage being used. The correct fuse value is also
dependent upon the ac line voltage. Follow the instruc-
tions in the LINE VOLTAGE SELECTION paragraph in
this section of the manual
OPERATING INSTRUCTIONS
OPERATING TIPS
The following recommendations will help obtain the best
performance from your wow and flutter meter.
1.
5.
Use the cable supplied with the instrument, or if other
cables are used, use shielded audio cable. ¡Radiated
noise may interfere with meter readings unless the input
cable is well shielded, especially at low signal levels.
Connect the ground lead of the input cable to a signal
ground reference point near the point of signal meas-
urement.
Line voltage must be within 110% of specified nominal
for accurate measurements.
The instrument and equipment under test must be free
from external vibration for accurate measurements.
Avoid operation in high temperature and humidity when
possible.
LINE VOLTAGE SELECTION
Before connecting the instrument to ac power the first
time, check the line voltage selector on the rear panel. Make
sure it is set for the line voltage you are using: 100, 117, 220,
or 240 VAC, 50/60 Hz. Also make sure the correct value fuse
is installed as follows: ;
0.5 A for 100 or 117 VAC line voltage.
0.3 A for 220 or 240 VAC line voltage.
PREPARATION FOR OPERATION
1.
Connect detachable power cord to receptacle on rear
panel and plug into ac outlet.
11
Turn POWER switch ON. FREQUENCY (Hz) display
serves as pilot light; display indicates "0000" with no
input.
Connect cable from GND terminal on rear panel of
instrument to chassis or common of equipment under
test.
Set controls to the following initial conditions:
a. RANGE: 1%.
b. FUNCTION: WTD.
с. INDICATION: as required (NAB in U.S. A.).
d. SENSITIVITY: 5 mV-30 V.
e. Mode: WOW FLUTTER
WOW/FLUTTER MEASUREMENT
1.
2.
Set INDICATION switch for desired type of measure-
ment standard, JIS, NAB, CCIR, or DIN.
Use pre-recorded wow and flutter test tape or record or
record a test tape as follows:
a. Connect cable from OSC OUTPUT terminals to
input of recorder (see Fig. 4).
b. Set 3 kHz-3.15 kHz switch to 3 kHz for JIS, NAB,
or CCIR standards. Set to 3.15 kHz for DIN
standards.
c Remember that wow and flutter occurring during
recording of the test tape will be present during
playback, and added to the wow and flutter occur-
ring during playback. Measured wow and flutter
represents the total wow and flutter introduced
OPERATING INSTRUCTIONS
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Rot
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Tapedeck
Record piayer
Fig. 4. Input and Output Connections to Wow & Flutter Meter.
for record and playback. One half the measured value
represents wow and flutter for playback only.
Connect output of equipment to be tested, such as tape
recorder or turntable, to INPUT terminals (see Fig. 4).
LEVEL MONITOR indicator should light if signal is of
adequate level and contains 3 kHz (JIS, NAB, or CCIR)
or 3.15 kHz (DIN) test frequency. If LEVEL MONITOR
indicator does not light, change SENSITIVITY switch
setting to 0.5 mV-100 mV.
Confirm that the FREQUENCY (Hz) display indicates
the wow and flutter test frequency (approximately 3000
or 3150 Hz). At high input levels, the LEVEL MONITOR
indicator may light at frequencies other than 3 kHz or
3.15 kHz.
6.
7.
Set FUNCTION switch for desired frequency compon-
ent:
WTD for weighted combination of wow and flutter
(frequency response of 0.2-200 Hz).
WOW for wow component only; 0.5-6 Hz for NAB
or JIS, 0.3-6 Hz for CCIR or DIN.
FLUTTER for flutter component only; 6-200 Hz.
UNWTD for unweighted combination of wow and
flutter (0.5-200 Hz for NAB or JIS or 0.3-200 Hz
for CCIR or DIN).
Set RANGE switch for highest obtainable meter reading
without going off scale. Read percent of wow flutter
from meter using a scale that corresponds to the range.
OPERATING INSTRUCTIONS
Connect to oscilloscope.
Connect to pen recorder or
digital memory scope for
making copy of wow flutter
measurement
memory scope. digital
memory scope or FFT ana-
lyzer for observing wow flutter
waveforms or analyzing
frequencies
Connect to oscilloscope Of
pen recorder for observing the
drift of wow flutter signal
Fig. 5. Use of Terminals on Rear Panel.
USE OF REAR PANEL TERMINALS Refer to Fig. 5.
1.
Connect TO SCOPE terminal to oscilloscope for observ-
ing wow and flutter waveform. Output is an ac voltage
of approximately 3 volts rms at full scale meter deflec-
tion.
Connect DRIFT terminals to oscilloscope or chart re-
corder to observe drift or speed error. Output is a de
voltage (use de coupling for oscilloscope input) of ap-
proximately 1 volt for each 1% of speed error.
Connect RECORDER terminals to digitial memory
scope or chart recorder for making a copy of wow and
flutter measurements. Output is a de voltage of ap-
proximately 1 volt for full scale meter deflection.
13
USE AS FREQUENCY COUNTER
1.
Set Mode switch to FREQ COUNTER position and con-
nect signal to be measured to INPUT terminals (see
Fig. 6).
The input signal level must be 100 mV to 30 Vrms. The
LEVEL MONITOR indicator will light, indicating that
adequate input signal level is applied.
Set the REFERENCE FREQUENCY switch of the rear
panel to select the desired time base; 50 Hz line volt-
age, 60 Hz line voltage, or internal crystal controlled
oscillator. |
The frequency of the input signal will be displayed on
the FREQUENCY (Hz) display. The counter is capable
OPERATING INSTRUCTIONS
“PV. 80 ~ BgK logo
035 PY?
Oscillator
Fig. 6. Input Connections for Frequency Counter.
14
of displaying counts of 0000 to 9999 Hz. The LEVEL
MONITOR indicator flickers above 10 kHz as an over-
flow indication. When the LEVEL MONITOR indicator
is flickering, the most significant digit is not displayed.
For example, if an input frequency of 13256 Hz is ap-
plied, the LEVEL MONITOR indicator flickers and the
FREQUENCY display shows a count of 3256.
It is usually desirable to terminate the input signal into
а 600 Q or 50 Q resistance (to match the output impe-
dance of the signal source). This minimizes ringing or
overshoot, especially when measuring square wave ог
rectangular wave signals.
MAINTENANCE
WARNING
1. The following instructions are for use by qualified
service personnel only. To avoid electrical shock, do
not perform servicing other than contained in the
operating instructions unless you are qualified to do
90.
2. A shock hazard is present when the case is removed
if the power cord is plugged into an ac outlet. AC
line voltage may be present on some circuits even
when the POWER switch is off.
CASE REMOVAL
Refer to Fig. 7. The case is constructed in two pieces.
The top case may be removed by removing the two screws
from the top and two screws from each side, then lifting the
case upward by the handle. The bottom case may be removed
by setting the instrument on the cord wrap/feet, removing
the four screws from the bottom and pulling the bottom case
away from the chassis.
FUSE REPLACEMENT
Refer to Fig. 8. The fuseholder is mounted on the rear
panel. Remove the fuseholder cap with a Phillips screwdriver
and replace the fuse with the correct value as listed on the
plate adjacent to the fuseholder.
15
Fig. 7. Case Removal
ADJUSTMENTS
Refer to Fig. 8 for the locations of adjustments. The fol-
lowing offset balance adjustments may be performed using
only an oscilloscope or accurate analog or digital multimeter.
Other adjustments require a Wow & Flutter Meter Calibrator.
MAINTENANCE
L Turn on the instrument with no input applied. Make
sure the LEVEL MONITOR lamp is off and the FRE-
QUENCY (Hz) display is indicating "0000".
92. Connect a multimeter or oscilloscope using de coupling
to the DRIFT terminals. Adjust VR6 for 0 volts dc.
3. Connect the multimeter or oscilloscope to the RE-
CORDER terminals. Adjust VR21 for 0 volts de.
4. Connect the multimeter or oscilloscope to the TO
SCOPE terminals. Adjust VR15 for 0 volts de.
INSTRUMENT REPAIR AND CALIBRATION SERVICE
This unit was carefully checked and calibrated at the
factory prior to shipment. Readjustment is recommended
only if repairs have been made in a circuit affecting calibra-
tion, or if you have reason to believe the unit may be out of
calibration. Recalibration should be attempted only if you
have the required test equipment. Recalibration of this
instrument requires a Wow & Flutter Meter Calibrator. Very
few instrument shops have such test equipment. If repair or
recalibration is required, return the unit to the B & K-
Precision Factory Service Department at Chicago. Also, if
additional servicing information is required, contact the
Factory Service Department.
16
100v. 120V. О БА
220V. 240V. 0 3A
Fig. 8. Fuse Replacement.
MAINTENANCE
I
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9 .
8 No eo
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Q vre (DRIFT) [
O
@ vR21 (TO RECORDER)
Moss À
VR15 (TO SCOPE)
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Front panel Top view Rear panel
Fig. 9. Location of Adjustments.
17
WARRANTY SERVICE INSTRUCTIONS
(For U.S.A. and its Overseas Territories)
1. Refer to the MAINTENANCE section of your B & K-Precision instruction manual for adjustments that
may be applicable. |
9 If the above-mentioned does not correct the problem you are experiencing with your unit, pack it
securely (preferably in the original carton or double-packed). Enclose a letter describing the problem
and include your name and address. Deliver to, or ship PREPAID (UPS preferred in U.S.A.) to the the
factory service center at Chicago. Use the following address.
B & K-Precision, Dynascan Corporation
Factory Service Operations
4050 North Ravenswood Avenue
Chicago, Illinois 60613
Tel (312) 327-7270
Telex: 25-3475
Also use this address for technical inquiries
and replacement parts orders.
18
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