Sony TC-640 Service Manual page 23

22. Crosstalk
Measurement
(between
channels)
23. Crosstalk
Measurement
(between
tracks)
Test Setup:
REC AMP
MIC jack
LINE OUT jack
Specification:
More than 55 dB (with SONY SLH tape)
Test Setup:
blank tape
AE osc REC AMP
MIC jack
LINE OUT jack
Specification:
More than 55 dB (with SONY SLH tape)
~23~
. Set the TAPE
. Thread a blank tape (SONY SLH tape) along the
tape path.
. Set the MIC VOL and LINE VOL controls to the
specified position on page 12.
. Deliver a 1 kHz signal of —50 dB (2.45 mV) to the
L-CH (R-CH) MIC jack only.
. Make sure that the level difference between both
channels is more than 55 dB.
Note:
Use the tape completely erased.
. Thread a blank tape (SONY SLH tape) along the
tape path.
SELECT switch to SPECIAL.
. Set the MIC VOL and LINE VOL controls to the
specified position on page 12.
. Deliver a 1 kHz signal of —50 dB (2.45 mV) to the
MIC jack.
. Place the unit in the stereo-record mode.
. Note the VI VM reading.
. Reverse the tape reels.
. Play back the opposite tracks of the recorded tape.
. Note the VTVM reading.
. Make sure that the level difference between step 6
and 9 is more than 55 dB.