Sony PMC-DR50L Service Manual page 21

Tape Speed Adjustment
Procedure :
– FWD Playback Mode –
test tape
WS-48B
(3kHz, 0dB)
set
1. Set to FWD playback mode.
2. Adjust RV160 so that the frequency counter reading becomes
3,000Hz.
Standard value : 2,970 to 3,030Hz
3. Set to REV playback mode.
Confirm the frequency should be within the standard value.
4. Confirm the frequency difference between beginning and the
end of tape should be within 1.5% (45Hz).
Adjustment Location : TC RF board
Cabinet, front (Rear side)
TC RF board
frequency counter
47k Ω
LINE OUT (JK301)
RV160 : Tape speed adjustment
TUNER SECTION
AM Section
BAND button : MW or LW
Volume : MIN
loop antenna A
AM RF signal
generator
30% amplitude modulation by 400Hz
signal
Output level : as low as possible
FM Section
BAND button : FM
Volume : MIN
FM RF signal
generator
22.5kHz frequency deviation by
400Hz signal.
Output level : as low as possible
set
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
MW/LW IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T2
MW FREQUENCY COVERAGE ADJUSTMENT
Adjust part Frequency display
L5
CT4
MW TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L4
CT102
– 21 –
0dB=1µV
60cm
loop antenna B
0.01 µ F
FM EXT.
ANT.
terminal
level meter
47k Ω
+
–
LINE OUT (JK301)
450kHz
reading on digital
voltmeter.
Adjustment value :1.4V
531kHz
Standard value : 1.2 – 1.6V
Adjustment value :7.5V
1,611kHz
Standard value : 7.1 – 8.0V
621kHz
1,404kHz
set