JVC RC-M60L - Adjustment of Cassette Recorder Amplifier; 000 S

| RC-M60L/LB
Adjustment
of
Cassette
Recorder
Amplifier
Conditions
@®
Bias
frequency
: 12V DC
anaes at LINE OUT terminals Connect a frequency counter across TP101. Adjust L301 so
stn
alae
FUNCTION:
TAPE
that
the
counter
reads
66.5
kHz.
MODE; STEREO
TAPE: NORMAL or METAL
BEAT CUT: ‘1 (NORMAL)”
@ Alignment of bias current and REC/PLAY frequency
response
(1) METAL
Connect an electronic voltmeter across TP101(TP201)
adjust VR101 and VR201 so that the voltmeter reads
Adjust
in
the
following
sequence.
5.4mV/10Q
(540uA).
(2) Normal
@ Head azimuth Adjust VR102,202 so that the voltmeter reads 2.7mV/10Q
Connect an oscilloscope to the LINE OUT jacks. Using test | (270A).
tape VTT-658 (10 kHz, -15 dB), adjust so the phase differ- | (1)’ METAL
Record and playback appling 1 kHz and 10 kHz (-35dBs)
to the LINE IN jacks, and re-adjust VR101,201 so that the
voltmeter connecting the LINE OUT jacks, indicates the
output difference (10 kHz/1 kHz) *hdB at the both test
frequencies.
(2)' Normal
Record and playback as same as METAL alignment, and
adjust VR102,202 so that the voltmeter indicates the out-
put difference (10 kHz/1 kHz)* AaB.
ence between the L and R outputs is 0° and maximize the
output level at the same time.
@ Tape speed
Connect a frequency counter to the LINE OUT jacks. Play-
ing back test tape VTT-656 (3,000 Hz), adjust the semi-fixed
resistor in the motor so that the frequency counter reads
3,010 + 10 Hz.
Pattern side of board $301 $302 $303
VR202 VR102
[ Mode |
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z ao
© <
5 = ee
Zz < fy
— 5 Fk E és
TP201 r% 58
—o 2a
ae
Metal
Bias
TP301
\ wa (eye
al wae
TP301 : Test Point for erasing current
METAL
.....
95
~
120mV/1220(95
~
120mA)
Fig.
16
[__}s304 Beat selector
How
to
Engage
Dial
Cord
1. Turn the dial drum fully counterclockwise (to the
lowest frequency).
2. Use Kevlar cord (1,330 mm long and 0.5 mm in dia-
meter).
3. Install the string in the sequence of the numbers.
No. 1416