Adjustments; Mechanical Adjustments Decree; 2-2.Electrical Adjustments -1+1++++Sssrrertereeeeterreesereeeeeees - Sony HST-231 Service Manual

SECTION 2
ADJUSTMENTS
2-1. MECHANICAL ADJUSTMENTS
PRECAUTIONS
1.Clean the following parts with a denatured-alcohol-moistened
swab:
record/playback heads __ pinch rollers
erase heads rubber belts
capstan idlers
2. Demagnetize the record/playback head with a head demagnetizer.
. Do not use a magnetized screwdriver for the adjustments.
4, After the adjustments, apply suitable locking compound to the
parts adjusted.
5.The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
Oo
Torque Measurement
Meter reading
FW
(0.42 — 0.97 ozeinch)
1—S5 gecm
FWD back tention CQ-102C (0.014 to 0.063 ozeinch)
FF, REW CO-201B (Ore sO ean
(0.97 — 2.21 ozeinch)
2-2. ELECTRICAL ADJUSTMENTS
OdB = 0.775V (AF)
OdB = 0.1 « V (RF)
CASSETTE DECK SECTION
@ The adjustments should be performed in the order given in this
service manual. (As a general rule, playback circuit adjustment
should be completed before performing recording circuit adjust-
ment.)
@ The adjustments should be performed for both L-CH and R-CH.
@ Switches and controls should be set as follows unless otherwise
specified.
DOLBY NR switch : OFF
TAPE: TYPES]
| type | Signal | Used for
Record/Playback Head Azimuth Adjustment
Note : Perform this adjustments for both decks.
Procedure :
1. Mode : FWD playback
test tape
P-4-A100
(10kHz, — 10dB) Oscilloscope
PCB
TC MAIN
CN405
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1 dB of peak.
output
level
within
1dB
——» screw position
Screen pattern
\inphase 45° 90° 135° 180°)
good wrong
3. After the adjustments, apply suitable locking compound to the
parts adjusted.
Adjustment Location :
Ajustment screw — REC/PB head (deck B) or blank tape
PB head (deck A)