Sony TC-188SD - 3-2. Electrical Adjustments: Overview; Tape Speed Adjustment

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3-2. ELECTRICAL ADJUSTMENTS
Note: The adjustments should be performed in
the order given in this service manual.
The adjustments should be performed for
both L-CH and R-CH.
Switches should be set as follows unless other-
wise specified.
DOLBY NR switch: OFF
EQ switch: NORMAL
BIAS switch: NORMAL
BIAS and EQ switch settings in accordance
with tape used are as follows.
[tape
|
BlASswitch
|
EQswitch
Standard Record
Supply
the
standard
input
level
signal
to
the
LINE
IN
jack
and
set
the
REC
LEVEL
control
to
obtain
the
standard
output
level.
Standard Input Level
:
0.77mV
|
0.25
V
input
level
(-60dB) | (-104B)
Standard Output Level
-HEAD-
load
impedance
|
100k2
50k2
0.44V 39mV 0.44V
output level
REC/PB
100 k2
17mV
(-33 dB)
(-5 dB) (-26 dB) (-5 dB)
== 14
| TC-188SD
Tape Speed Adjustment
Procedure:
Mode: Playback
speed checker
LFM-30
or
digital frequency
counter
test tape
WS-48
(3kHz, 0dB)
LINE OUT
Adjust RV602 to obtain the specified values
below.
Specification:
Frequency difference between beginning and
end of tape should be within 0.7% (20 Hz).
Adjustment Location:
- RV602
If correct tape speed cannot be obtained by
adjusting RV602, Solder CG) or (2).
servo amp
board
601
®D oT
Vi0
VIO
@-
Solder portion Tape speed