Teac A-450 - TAPE SPEED;WOW AND FLUTTER

4-6. TAPE SPEED/WOW AND FLUTTER
Specification:
Tape Speed Deviation: 3,000 Hz + 30 Hz
Wow and Flutter: Playback: 0.07% (WRMS)
Record/Playback:
0.10% (WRMS)
NOTE
Before performing this adjustment, clean all parts
in the tape path, particularly the Capstan, the
Pinch. Roller and the Heads 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 check, and correct if necessary, 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.
4- i 1. TAPE SPEED
_
Connect test equipment to the deck, except the AF
oscillator, as shown in Fig. 4-8.
Set the OUTPUT control on the deck to proper setting.
Set the EQ switch to the “3” position, and then load
and play a TEAC MTT-111 test tape (3,000 Hz signal is
recorded).
Verify the reading on the frequency counter is within
the specified range of 3,000 Hz + 30 Hz.
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.
4-6-2. WOW AND FLUTTER
After making the tape speed measurement, perform the
wow and flutter test using the Playback Method and the
Record/Playback Method successively.
proeeee METHOD
3.
4.
14
Repeat steps 1 — 3 in 4-6-1.
Read the indication on the wow and flutter meter.
The wow and flutter value should be 0.07% WRMS,
max.
If the wow and flutter is out of the specification, check
the Pinch Roller pressure and the take-up torque, and
see that the tape path is clean, and that the Capstan
Beltis not stretched or oily.
If the above checks are ineffective for excessive wow
and flutter correction, repair or replace the Pinch
Roller, the Capstan Belt and/or any other detective
parts.
OSCILLATOR
FREQUENCY COUNTER
DECK wow & FLUTTER METER
LINE IN
(L}
under TEST
T4833
Fig. 4-8 Tape Speed/Wow and Flutter Measurement Setup
RECORD/PLAYBACK METHOD
NOTE
When using this method, adopt the maximum wow
and flutter value obtained by repeated play and stop
modes of operation. This operation is necessary to
make sure wow and flutter content between record
and playback will not be in phase to create a false
reading.
Connect test equipment to the deck as shown in Fig.
4-8.
Set both LINE and OUTPUT controls on the deck to
proper setting.
Load a TEAC MTT-502 test tape (blank) and set the
BIAS/EQ switches in the “3” positions.
Apply and record a 3,000 Hz signal.
Rewind and play this recorded portion.
Read the indication on the wow and flutter meter.
The wow and flutter value should be 0.10% WRMS, max.
If the measured value is out of the specification, repair
using the same methods as stated in steps 4 — 5 inthe
Playback Method procedure.
BOTTOM VIEW w/
FLYWHEEL REMOVED
FAST WIND
ROLLER reel we IDLER
SUPPLY TAKE-UP
REEL TABLE REEL TABLE
T-481
Fig. 5-1 Bottom View w/Flywheel Removed