Amplifier Adjustments - Sanyo DC-X850 Service Manual

AMPLIFIER ADJUSTMENTS
.
Make the
following adjustments after first cleaning the head and checking the adjustment of the head azimuth.
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G:,N ~
RR5mimsm
(R-CH)
Id"
VR302 VR301
TAPE OUT
(R-CH) (L-CH)
R-CH
E
L-CH
TAPE '"A "
CN373
PLAY GAIN
Immg
o
VR308 VR307
(R-CH) (L-CH)
(
BIAS
1
x 67
k
)
o & 6
Adjustment Item
Test
tape
;~OLsB;,
(a) Playback output TCC-130
adjustment (Dolby tape)
CWF
(b) Recording I Playback
AC-224
~F
gain adjustment (Normal)
(c) Recording I Playback Ac *24
frequency response
-
adjustment
(Normal) 'F
Measuring
input output Adjustment Adjustment
Instrument connection
connection
location
value
I
I
I (TAPE "A") SVR3011
AC-voltmeter
-
TAPE OUT
SVR302
(CN373)
(TAPE "B") SVR303
580 'v
SVR304
VIDEO
AC-voltmeter
-44 dB, TAPE OUT SVR307
Otl dBat
AF-oscillator 1 kHz,
(CN373) SVR308
1 kHz and
10 kHz
10 kHz
(a) Playback output adjustment
(1) TAPE "A"
Play the test tape and adjust SVR301 (L-CH) and SVR302
(R-CH) so that playback output becomes !N30mV.
:2) TAPE "B"
Play the test tape and adjust SVR303 (L-.f3-t) and SVR304
(R-CH) so that playback output becomes 580mV.
b) Recording / Playback gain adjustment
DOLBY NR switch : OFF
Input signal : -24 dB, 1 kHz
Tape to be used : NORMAL (AC-224, etc-)
Introduce input signals to the VIDEO terrrrinals,
and with the unit in the REC, PAUSE mode.
Record the input signal.
Press the REWIND button and rewind the tape
to the beginning of the recording just made.
Press the PLAY button.
Adjust SVR305 (L-CH) and SVR306 (R-Ct-1)
so that the recording and playback outpdt
level difference become f 1dB.
Repeat steps (1) to (5).
(c)
(1)
(2)
(3)
(4)
(5)
(6)
Recording / Playback frequency response
adjustment
DOLBY NR switch : OFF
Input signal :-44 dB,
1
kHz, 10 kHz
Tape to be used : NORMAL (AC-224, etc.)
Introduce input signals to the VIDEO terminals.
With the unit in the REC mode.
Record these input signals (1 kHz + 10 kHz + 1 kHz +
10 kHz).
Press the REWIND button and rewind the tape to the
beginning of the recording just made.
Press the PLAY button.
Adjust SVR307 (L-CH) and SVR308 (R-CH)
so that the 10 kliz and 1 kHz output level difference
become ~ 1 dB.
Repeat steps (1) to (5).
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