JVC RC-S22 C - Adjustment of Cassette Amplifier

RC-S22 C/W/JW/WH/L/LB/LD
Adjustment
of
Cassette
Mechanism
When
cassette
mechanism
parts
are
replaced,
be
sure
to
check
the
following
items.
1. Power supply
Rated voltage: DC 4.5 V
Motor operating voltage range: Constant supply voltage
voltage 23-4.5V
4.8 cm/sec. +3%
2.
Tape
speed
(3000
Hz)
2%
ae
VTT-656
Variation
range
—-2%
3.
Wow®&
flutter
|
0.28%
or
less
(JIS
WRMS)
Wow
meter
VTT-656
PLAY: 28— 70g.cm
FF: 50—100 g.cm
REW: 50—100 g.cm
PLAY: 160 mA or less C-60
FF:
250
mA
or
less
DC
ammeter
Use
one
with
no
irregu-
250 mA or less larities in take-up torque,
4. Torque of the
take-up reel
5. Current
consumption
(Motor only)
To be measured when the pinch
roller stops rotating after being
6. Clamping force
ee pinch 200 — 280 g pulled in the horizontal direction
with the tension gauge.
7. Thrust wobble
of the flywheel 0.05—0.2 mm Clearance gauge —
€ In the PLAY mode, the clearance
£ . ; 3 ,
8. Head adjust- 3 Bo @ saat oe a value ee Any type of cassette
ment for PLAY L on the left. Also be sure neither tapes
a = corner of the head comes into
contact with the cassette shell.
E
9. Head adjust- é
ment
for
-
CUE/REVIEW a
10. Auto stop At a reduced voltage of 2,3 V, the unit should auto-stop within 10 sec. | Any type of cassette
Operation after winding is finished in PLAY, FF and REW modes. tape
11. Fast rewinding | FF: 110 sec. or less
time REW: 110 sec. or less | iis J
Adjustment of Cassette Amplifier
(Conditions)
Power source : DC 4.5 V Volume level : MAX. Tape : Norm
Output
:
Speaker
terminal
8
22
load
Installation
:
Horizontal
TONE
:
High
Alignment Point
Screw for playback head
azimuth adjustment
(fastening the head)
Semi-fixed resistor
on the Governor
C.B. VR501 Governor CB.
VR501
Alignment Methods
Test Tape
1. Head azimuth VTT-657
be kHz)
2. Tape speed adjust- VTT-656
ment and checking (3 kHz)
of wow & flutter
Adjust so that the output phase difference between
L and R channels is minimum and that output is
maximum.
Adjust so that the electronic counter reads within
3,015 Hz + 15 Hz.
Wow & flutter should be 0.28% (WRMS) or less.
T301 on the P.W.B.
VTT-662
(333 Hz)
Connect an electronic voltmeter to the speaker
terminals so that the electronic voltmeter reads
more than 2.8 V.
Connect a frequency counter to transistor Q302(B).
Adjust so that the electronic counter reads 48 kHz.
3. Checking of P.B.
maximum output
4. Bias frequency
adjustment
6 No. 1534