Philips MCM510/22/25/33 Service Manual page 37

TAPE ADJUSTMENT & CHECK TABLE
TEST RECORDER
CASSETTE MODE
SBC420
PLAY
MOTOR SPEED
3150Hz
SBC420
PLAY
WOW & FLUTTER
3150Hz
PLAY FWD
SBC420
ADJUST AZIMUTH
10kHz
PLAY REV ^
SBC420
PLAYBACK LEVEL
PLAY
315Hz
& FREQ. RESPONSE
CHECK RECORD/PLAYBACK FREQUENCY AND DISTORTION
Inject 3mV signals
100Hz, 250Hz, 1kHz, SBC419A
10kHz, 12.5kHz or RECORD
SBC420
via or
3 4
RECORDED
PLAY
CASSETTE
Inject 1kHz 8.85mV
SBC419A
or
RECORD
via or
3 4
SBC420
RECORDED
PLAY
CASSETTE
SBC419A : 4822 397 30069 ^
SBC420 : 4822 397 30071 *
level(dB)
8dB 6dB 8dB
80 250 4k 12.5k
figure. 1
9 - 3
ADJUST
MEASURE
READ ON
ON
with
frequency
check
counter
check
W&F-meter
1 or 2
left hand screw
max. output level
LEFT RIGHT
mV-meter
right hand screw
mV-meter
check
or
1 2
mV-meter
check
LEFT RIGHT
or
1 2
THD-meter check
LEFT RIGHT
For Auto-reverse version only
If high frequencies are not within limits, decrease bias and re-measure.
If distortion is too high, increase bias and re-meaure
level(dB)
8dB 6dB
f(Hz)
100 250 4k 10k
figure. 2
to
3150Hz +/- 2%
< 0.4 % DIN
& left=right
125mV +/- 3dB
(see fig.1 for freq.
response)
limits see fig. 2 *
< 3% *
8dB
f(Hz)
9 - 3