SONY PMC-DR50
Manual de Servicio

SECTION 4 ADJUSTMENTS
4-1. MECHANICAL ADJUSTMENTS
TAPE RECORDER SECTION
PRECAUTION

Record/Playback/Erase Head Azimuth Adjustment Procedure : 1. Mode : FWD playback
test tape P-4-A100 (10kHz, �10dB) 47K � set LINE OUT (JK301) level meter

1. Clean the following parts with a denatured-alcohol-moistened swab : record/playback/erase head pinch roller rubber belts capstan 2. Demagnetize the record/playback/erase head with a head demagnetizer. 3. 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. Torque Measurement
Torque Forward Forward Back Tension Reverse Reverse Back Tension FF/REW CQ-102RC CQ-102RC CQ-201B Torque Meter CQ-102C CQ-102C Meter Reading 36 to 61 g � cm (0.5 to 0.84 oz � inch) 2 to 6 g � cm (0.028 to 0.083 oz � inch) 36 to 61 g � cm (0.5 to 0.84 oz � inch) 2 to 6 g � cm (0.028 to 0.083 oz � inch) 61 to 143 g � cm (0.85 to 1.98 oz � inch)

2. Turn the adjustment screw for the maximum output levels. If these levels do not match, turn the adjustment screw until both of output levels match together within 1dB.

L-CH peak within output 1 dB level

within 1 dB

Screw position

R-CH peak

screw position L-CH peak R-CH peak

Tape Tension Measurement
Mode FWD REV Tension Meter CQ-403A CQ-403A Meter Reading more than 100g (more than 3.53 oz) more than 100g (more than 3.53 oz)

3. Phase Check Mode : FWD playback
test tape P-4-A100 (10kHz, �10dB) L-CH 47K � Osilloscope

set

V

H

4-2. ELECTRICAL ADJUSTMENTS
TAPE RECORDER SECTION 0dB = 0.775V

R-CH

47K � LINE OUT (JK301) screen pattern

1. The adjustnemts should be performed in the order in the service manual. (As a general rule playback circuit adjustment should be completed beforeming recording circuit adjustment.) 2. The adjustments should be performed for bothe L-CH and RCH unless otherwise indicated. Standard Intput Level
Input terminal source impedance input signal level LINE IN 10k� 0.5V (�3.8dB)

in phase 45° good

90°

135°

180°

wrong

4. Change the reverse playback mode and repeat the step 1 to 3. 5. After the adjustment, lock the adjustment screw with suitable locking compound. Adjustment Location : � record/playback/erase head �

Standard Output Level
Output terminal load impedance output signal level LINE OUT 47k� 0.5V (�3.8dB)

Test Tape
Type P-4-A100 WS-48B Signal 10kHz, �10dB 3kHz, 0dB Used for Azimuth Adjustment Tape Speed Adjustment

FWD side

REV side

adjustment screw

� 16 �