Sony TXD-RE210 Service Manual page 9

Record Level Adjustment
Procedure :
1. Mode : Record
AF OSC
315Hz 72.3mV (–20.6dB)
10 k Ω
attenuator
600 Ω
TAPE IN
2. Mode : Playback
recorded
portion
set
TAPE OUT
3. Confirm playback the signal recorded in step 1 become adjust-
ment level as follows.
4. If these levels do not adjustment level, adjust the RV111
(L-CH) and RV211 (R-CH) to repeat step 1 and 4.
Adjustment Level :
TAPE OUT level : – 26± 0.5dB (36.7 to 41.1mV)
Adjustment Location : MAIN board.
[AUDIO BOARD] (Conductor side)
Record Bias
(R) (L)
RV22 RV12
[MAIN BOARD]
(Component side)
blank tape
CS-123
set
level meter
47 k Ω
+
–
RV71 (NORMAL) Tape speed
RV21(R)
Playback Level
RV11(L)
RV211 : Record level (R-CH)
RV111 : Record level (L-CH)
CD SECTION
Note :
1. CD Block basically constructed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use the oscilloscope with more than 10MΩ impedance.
4. Clean an object lens by an applicator with neutral detergent when
the signal level is low than specified value with the following
checks.
S-Curve Check
BD board
TP (FE)
TP (VC)
Procedure :
1. Connect oscilloscope to test point TP(FE) and BD board.
2. Connect between test point TP (FEI) and TP (VC) by lead wire.
3. Turned Power switch on.
4. Put disc (YEDS-18) in and turned Power switch on again and
actuate the focus search. (Actuate the focus search when disc
table is moving in and out.)
5. Check the oscilloscope waveform (S-curve) is symmetrical be-
tween A and B. And confirm peak to peak level within
3 ±1Vp-p.
6. After check, remove the lead wire connected in step 2.
Try to measure several times to make sure that the ratio of
Note :
r
A : B or B : A is more than 10 : 7.
Take sweep time as long as possible and light up the bright-
r
ness to obtain best waveform.
RF Level Check
BD board
TP (RF)
TP (VC)
Procedure :
1. Connect oscilloscope to test point TP (RF) on BD board.
2. Turned Power switch on.
3. Put disc (YEDS-18) in and playback.
4. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
Note :
Clear RF signal waveform means that the shape "
clearly distinguished at the center of the waveform.
RF signal waveform
– 9 –
oscilloscope
+
–
symmetry
A
within 3 ± 1Vp-p
B
oscilloscope
+
–
◊
" can be
VOLT/DIV : 200mV
TIME/DIV : 500nS
+0.25
level : 1.2 Vp-p
–0.20