Sony TC-377 Service Manual page 21

20. Cross-Talk Measurement
(between tracks)
Control/Switch Setting:
TAPE SELECT switch:
TAPE SPEED selector:
MONITOR switch:
LINE RECORD
VOLUME control:
NORMAL
7% ips (19 cm/s)
TAPE
See page 16
Procedure:
1. Mode: stereo record
af osc
2
Oo
blank tape
LINE IN (L) (R)
400 Hz, OdB (0.78 V)
2. Turn the reels over.
3. Mode: playback
adjacent track of
the recorded portion VTVM
Cr)
400 Hz bandpass
100k filter
LINE OUT
(L, R)
level difference:
greater than 65 dB
adjacent track of
the recorded
portion
tape tracks .
CMLL MLL -y
a a Sa
2 : cS LINE OUT (R)
WLLL LLL
aaa ae
4 ; LINE OUT (L}
21. Minimum Input Level Check
Control/Switch Setting:
MONITOR switch: SOURCE
Procedure:
A. MICROPHONE Jack Level Check
1. -Set LINE RECORD VOLUME to MIN and
MIC RECORD VOLUME to MAX position.
Supply 1kHz signal into MICROPHONE jack
and adjust attenuator to obtain O0dB (0.78V)
VTVM reading.
Be sure that MICROPHONE jack level is less
than ~72 dB (0.2 mV).
B. LINE IN Jack Level Check
1. Set MIC RECORD VOLUME to MIN and
LINE RECORD VOLUME to MAX position.
Supply 1kHz signal into LINE IN jack and
adjust attenuator to obtain OdB (0.78V)
VTVM reading.
3. Be sure that LINE IN jack level is less than
-22 dB (61.5mV).
Mode: record
f _——,
VTVM
Ez
10kQ. (for
LINE IN only)
600
MICROPHONE
less than -72dB (0.2mV)
LINE IN
less than -22dB (61.5mV)
attenuator 100k?
0 5 O
I | me B
2 ae
LINE OUT