Mechanical Adjustments; Electrical Adjustments; Tape Deck Section; Tuner Section - Sony XR-1750 Service Manual

SECTION 4

MECHANICAL ADJUSTMENTS

1. Clean the following parts with a denatured-alcohol-moistened
swab:
playback head
rubber belt
idler
2. Demagnetize the playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. The adjustments should be performed with the power supply
voltage (14.4 V) unless otherwise noted.
• Torque Measurement
Mode Torqu Meter
Forward CQ-102C
Forward
CQ-102C
Back Tension
Reverse CQ-102RC
Reverse
CQ-102RC
Back Tension
FF, REW CQ-201B
• Tape Tension Measurement
Mode Torqu Meter
Forward CQ-403A
Reverse CQ-403R
pinch roller
capstan
Meter Reading
35–65 g•cm
(0.49–0.90 oz•inch)
0.5–5.0 g•cm
(0.01–0.07 oz•inch)
35–65 g•cm
(0.49–0.90 oz•inch)
0.5–5.0 g•cm
(0.01–0.07 oz•inch)
60–200 g•cm
(0.83–2.78 oz•inch)
Meter Reading
more than 60 g
(more than 2.12 oz)

ELECTRICAL ADJUSTMENTS

See the adjustment location from on page 17 for the
adjustment.

TAPE DECK SECTION

TAPE DECK SECTION
Tape Speed Adjustment Tape Speed Adjustment
Procedure: Procedure:
1. Put the set into the FWD PB mode. 1. Put the set into the FWD PB mode.
test tape
WS-48A
(3 kHz, 0 dB)
set
Specification: Constant speed
Speed checker
–1.5 to +2.5%
Adjustment Location: See page 17.

TUNER SECTION

FM S Meter Adjustment
Setting:
SOURCE button
FREQUENCY SELECT switch : 9 k (E, Australian model)
FM RF signal
generator
0.01 µF
Carrier frequency : 97.9 MHz (US model)
: 98.0 MHz (E, Australian model)
Output level : 30 dB (31.6 µV)
Mode : mono
Modulation : 1 kHz, 75 kHz deviation
Procedure:
1. Tune the 97.9 MHz (US model) or 98.0 MHz (E, Australian
model).
2. Adjust RV1 on TU1 so that the digital voltmeter reading is
3.1 V.
Adjustment Location: See page 17.
– 16 –
SECTION 5
0 dB=0.775 V 0 dB=0.775 V
speed checker
or
frequency counter
10 k Ω
– +
LINE OUT
Frequency counter
2,955 to 3,075 Hz
0 dB=1 µV
: FM
antenna jack (J1)
digital voltmeter
set
TU1 pin !•