Sony TC-KB820S, Руководство по обслуживанию

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Tape Speed Adjustment
Procedure:
Mode: playback
1. Set to FWD playback mode.
2. Adjust RV71 so that the frequency counter reading becomes
3,000 ± 90 Hz.
3. If, the frequency counter reading does not become 3,000 ±
90Hz.
Turn RV72 and back to 1st. step again.
Note:
Turn RV72 to clockwise – Tape speed becomes fast.
Turn RV72 to counter clockwise – Tape speed becomes slow.
4. Frequency difference between the beginning and the end of
the tape should be within 1%.
Adjustment Location: AUDIO board (See page 12.)
Sample value of Wow and Flutter: 0.3% or less W.RMS (JIS)
(WS-48B)
Playback Level Adjustment
Procedure:
Mode: playback
Adjust RV11 (L-CH) and RV21 (R-CH) so that the reading on
level meter meets the adjustment limits below.
Adjustment Limits:
LINE OUT level: –7.7±0.5 dB (0.301 to 0.338 V)
Level difference between channels: within 0.5 dB
Check that the LINE OUT level does not change even if Playback
and Stop operation is repeated several times.
Adjustment Location: AUDIO board (See page 12.)
+
–
set
LINE OUT
frequency counter
test tape
WS-48B
(3 kHz, 0 dB)
47 k
Ω
+
–
set
LINE OUT
47 k
Ω
test tape
P-4-L300
(315 Hz, 0 dB)
level meter
Bias Consumption Current Adjustment
Procedure:
1. Set RV81 (L-CH) and RV91 (R-CH) to mechanical center and
turn the set recording mode.
2. Connect digital voltmeter as shown by the following table.
3. Adjust the following transformers for the minimum readings
on the digital voltmeter.
Measurement Point Adjustment Part Value
L-CH
1
and
2
, TP321 T81
minimum
R-CH
3
and
2
, TP321 T91
Adjustment Location: AUDIO board (See page 12.)
Record Bias Adjustment
Setting:
REC LEVEL control: Standard Record (See page 10.)
Procedure:
1. Mode: record
2. Mode: playback
3. Adjust RV81(L-CH) and RV91 (R-CH) so that 10 kHz play-
back output is 0±0.5 dB relative to the 315 Hz output.
Adjustment Location: AUDIO board (See page 12.)
–
+
set
LINE IN
(no signal)
B+ (+7.5 V)
TP81
3 2 1
R-CH L-CH
digital voltmeter
CS-413 blank tape
set
AF OSC
Attenuator
LINE IN
315 Hz
10 kHz
50 mV (–23.8 dB)
600
Ω
10 k
Ω
CS-123
blank tape
+
–
set
LINE OUT
47 k
Ω
recorded
portion
level meter