Sony TC-WR645S - Page 8

Bias Consumption Current Adjustment DECK-B
This adjustment should be performed when replacing the head assy
or the bias oscillating transformer (T81, T91).
Procedure :
( ): R-CH
digital
blank tape voltmeter
CS-413
| 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 Value : Maximum 220mV
Adjustment Location : AUDIO board
Record Bias Adjustment
Setting :
REC LEVEL control : standard record position (Refer to page 7.)
Procedure :
1. Record Mode
AF OSC
“a
blank tape
CS-123
3)
} 50mV( — 23.8dB)
altenuator
LINE IN
1) 315Hz
2) 10KHz
2. Playback Mode
recorded
portion
ic
Confirm that the 1OkHz playback output is O + O.5dB relative to the
315Hz output. If necessary, adjust RV81(L-CH), RV91(R-CH) and
repeat the steps given above.
LINE OUT
Adjustment Location : AUDIO board
Record Level Adjustment |DECK-B
Setting :
REC LEVEL control : standard record position (Refer to page 7.)
Procedure :
' J, Record Mode
AF OSC
blank tape
e CS-123
(?)
o—o
ad
o—o
2. Playback Mode
recorded VTVM
portion
Confirm playback the tape recorded become adjustment level as
follows.
If necessary, adjust RV102(L-CH), RV202(R-CH) and repeat the
steps 1 and 2.
Adjustment Value :
LINE OUT level : ~ 23.8 £ 0.5dB (47.2 to 53mV)
Adjustment Location : MAIN board