Pioneer CT-70R Service Manual page 34

6. Recording/playback Frequency Response Adjustment
sacl
Mode Input signal & test tape Adjustment location
Measuring location
Adjustment value
Remarks
Apply 315Hz/~30dBv to
LINE INPUT terminals.
1 Forward INPUT level control
recording pause
Record 315Hz and
10kHz signals onto the
STO-608A test tape, and
then play those recorded
sections.
VR315 {left ch.)
VR316 (right ch.)
2 Forward re-
cording/play back
Left and right
OUTPUT terminals
~27dBv
(44.7mV)
INPUT tevel control position
setting
—_—
Repeat the recording and playback, and adjust
accordingly until the 10kHz playback level is +0.5
dB in respect to the 315Hz signal.
3 | Record 315Hz -15kHz (—30dBv input) onto the STD-608A test tape, and play (FWD) the recorded signals back. Check that the playback signals con-
form with the permitted
frequency response zone shown
in Fig. 10-16. If the rated specifications are not satisfied, readjust VR315 and VR316
(to
+25
obtain a 10kHz signal level of at least +0.5 -05 dB in respect to the 315Hz level).
Record 315Hz and 10kHz
signals onto the STD-608A
test tape, and then play
those recorded sections.
VR317 (left ch.)
VR318 (right ch.)
4 | Reverse re-
cording/play back
Left and right
OUTPUT terminals
Repeat the recording and playback, and adjust
accordingly until the 10kHz playback level is +0.5
dB in respect to the 315Hz signal.
obtain a 10kHz signal level of at least +0.5 +25 gB in respect to the 315Hz level).
Record 315Hz and 10kHz
signals onto the STD-603
test tape, and then play
those recorded sections.
VR313 (left ch.)
VR314 {right ch.)
Forward re-
cording/play back
Left and right
OUTPUT terminals
Repeat the recording and playback, and adjust
accordingly until the 10kHz playback level is +0.5
dB in respect to the 315Hz signal.
7 Record 315Hz —-15kHz {-30dBv input) signals onto the STD-603 test tape, and play the recorded signals back. Check that the playback signals con-
form with the permitted frequency response zone (for STD-603) shown in Fig. 10-17.
(for the 140mV to 180mV range referred to in "Erase Current Adjustment").
oe Adjustment item ——
VR301, 302 Playback equalizer
VR303, 304 Playback level
VR306 METAL bias
VR307, 308 NORM recording level
VR309, 310 CrO, recording level
VR311, 312 METAL recording level
VR313, 314 CrO, bias
VR315, 316 NORM (FWD) bias
VR317, 318 NORM (REV) bias
VR319 Leader tape detector level
44
Dolby NR assembly
Mother assembly
VR303
Fig. 10-15 Adjustment locations
TP.2
(DOL.R)