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Teac A-650 Service Manual page 14

Stereo cassette deck with dolby system

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PLAYBACK ME HOD
4.
5-5-1.
APE SPEED
1.
2.
4.
5-5-2. WOW AND FLU
ER
Fig.
Adjustment Location
Specification:
Tape Speed Deviation:
Tape Speed Drift:
After making the tape speed measurement, perform the
wow and flutter test using the Playback Method and the
Record/Playback Method successively.
Connect test equipment to the deck, except the AF
oscillator, as shown in Fig. 5-7.
Set the OUTPUT control on the deck to obtain conve ­
nient output.
Set the EQ switch to the " 3 " position, and then load
and play a TEAC MTT-l 11 test tape (3,000 z signal is
recorded).
Adjust the semi-fixed resistor as shown in Fig. 5-8 for
reading of 3.000
z ± 5
z on the frequency counter.
(NOTE: This tape speed setting should be done after
approx. 30 seconds of operating time of the deck.)
Then, verify the reading on the frequency counter as
within the specified range of 3,000
z ± 30
z, and
the Tape Speed Drift is within 15
z at any portion
of the tape run.
If the tape speed is extremely out of the specification,
check the Pinch Roller pressure and the tape driving
function for correction, and make sure the tape path is
clean.
1.
2.
Play the MTT-l 11 test tape.
Read the indication on the wow and flutter meter.
The wow and flutter value should be 0.07% WRMS,
max. or 0.15% RMS, max.
If the wow and flutter is out of specification, check
the Pinch Roller pressure and the take-up torque, see
that tire tape path is clean, and that the Capstan Belt
is not stretched or oily.
If tire above checks are ineffective for excessive wow
and flutter correction, repair or replace the Pinch
Roller, the Capstan Belt and/or any other defective
parts.
3,000 z ± 30 z
15
z
Playback: 0.07% (WRMS)
0.15% (RMS)
Record/Playback:
■ ■ ■ ■ ■
NOTE
Before performing this adjustment, clean all parts
in the tape path, particularly the Capstan, the
Pinch Roller and the
eads with the appropriate
liquid from the TEAC TZ-261 Cleaner Kit or
with pure alcohol.
Wow and flutter should be checked in two ways;
Playback only and Record/Playback methods.
First correct tape speed and wow and flutter
using the playback only method. Then measure
wow and flutter using record and playback
method.
As the measured results may vary with respect to
location on tape at which it was taken, three
points
at beginning, middle and near the end
of the tape
should be measured. Tire worst
case reading must satisfy the specification.
1.3

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