Sony CMT-CP11 Service Manual page 14

Playback level Confirmation and Adjustment
Procedure:
Mode: Playback
test tape
WS-48B
(3 kHz, 0 dB)
set
MAIN board
LINE OUT jack (PJ301)
L-CH, R-CH
Confirm playback level is within specification values as follows.
If these levels are out of specification values, adjust the RV151 (L-
CH) and RV251 (R-CH) on the MAIN board so that the level meter
reading become within specification values.
Specification values:
PJ301 PB level: 301.5 to 338.3 mV (–8.2 to –7.2 dB) level difference
between the channels: within ±0.5 dB
Adjustment Location: MAIN board
REC Bias Confirmation and Adjustment
Procedure:
1. Mode: Record
MAIN board
MD IN jack (PJ301)
L-CH, R-CH

1) 315 Hz

2) 10 kHz

AF OSC
600 Ω
attenuator
2. Mode: Playback
recorded
portion
set
MAIN board
LINE OUT jack (PJ301)
L-CH, R-CH
3. Confirm playback the signal recorded in step 1 become
specification values as follows.
If these values are out of specification values, adjust the RV153
(L-CH) and RV253 (R-CH) on the MAIN board to repeat steps
1and 2.
Specification values: Playback output of 315 Hz to playback
output of 10 kHz: ± 0.5 dB
Adjustment Location: MAIN board
frequency counter
+
–
50 mV (–23.8 dB)
blank tape
CN-123
set
level meter
+
–
REC Level Confirmation and Adjustment
Procedure:
1. Mode: Record
MAIN board
MD IN jack (PJ301)
L-CH, R-CH
315 Hz, 50 mV (–23.8 dB)
AF OSC
600 Ω
attenuator
2. Mode: Playback
recorded
portion
set
MAIN board
LINE OUT jack (PJ301)
L-CH, R-CH
3. Confirm playback the signal recorded in step 1 become
specification values as follows.
If these values are out of specification values, adjust the RV252
(R-CH) and RV152 (L-CH) on the MAIN board to repeat steps
1 and 2.
Specification values:
PJ301 PB level: 47.2 to 53.0 mV (– 24.3 to – 23.3 dB)
Adjustment Location: MAIN board
– MAIN BOARD (Conductor Side) –
RV252 (R)
IC352
RV152 (L)
RV251 (R)
Playback Level
RV151 (L)
RV253 (R)
REC Bias
RV153 (L)
blank tape
CS-123
set
level meter
+
–
LINE OUT (L/R)
PJ301 MD IN (L/R)
VIDEO IN (L/R)
REC Level
13