Sony TC-WR990 - Specific Calibration Procedures; Bias Consumption Current Adjustment; Record Level Adjustment Procedure

(TC-WR590 only)
Bias Consumption Current Adjustment
This adjustment should be performed when replacing the
head assy or the bias oscillating transformer (T81,T91).
Procedure :
( ):R-CH
digital
voltmeter
blank tape
CS-412
| set
LINE IN
no signal
1.Connect the digital voltmeter to test point TP81.
2.Set RV81 (RV91) to mechanical center.
3.Set to FWD record mode.
4. Adjust T81 (T91) so that the digital voltmeter reading
becomes minimum.
Adjustment Location : AUDIO board
Record Level Adjustment
Setting:
REC LEVEL control : standard record position (Refer to
page 9.)
Procedure:
1.Record Mode
AF OSC
blank tape
10k 2 CS-122
ae attenuator
0 —_—I
oo O
11 ooo | —_
[ EE
LINE IN
1) 315Hz
}semv (~ 27.8dB)
2) 10KHz
2.Playback Mode
recorded
k es
Playback the signal recorded in step 1.
Confirm that the 10kHz playback output is 0+0.5dB relative
to the 315Hz output. If necessary, adjust RV81 (L-CH), RV91
(R-CH) and repeat the steps given above.
WR521 RV12 (L-CH), RV22 (R-CH)
LINE OUT
Adjustment Location : AUDIO board
|
Record Level Adjustment
Setting:
REC LEVEL control: standard record position (Refer to
page 9.)
Procedure :
1.Record Mode
AF OSC
blank tape
10k 2 CS:122
a) attenuator
ole
oO o
Ilooo f oe
|
LINE IN
315H2 31.6mV (-- 27.8dB)
2. Playback Mode
recorded
portion
LINE OUT
Confirm playback the tape recorded become adjustment
level as follows.
If necessary, adjust RV101 (L-CH), RV201 (R-CH) and repeat
the steps 1 and 2.
Adjustment Value :
LINE OUT level : — 27.7+0.5dB (30.2 to 33.8mV)
Adjustment Location: MAIN board
— Adjustment Parts Location Diagrams —
Record Level
OF
(R) (L)
RV201 RV
[MAIN BOARD} eibareic as