JVC KD-D30 - Main Adjustments

KD-D30 A/B/C/E/J/U
Main Adjustments
{1} Equipment and measuring instruments
used for adjustment
. Electrical adjustment
1) Electronic voltmeter
2) Audio frequency oscillator (range: 50—20 kHz and
output O dB with impedance 600 Q)
3) Attenuator
4) Standard tapes for REC/PB
Maxell UD — SF tape
TDK SA — SA tape
JVC ME — Metal tape
5) Reference tapes for playback (JVC Test Tape)
VTT-658 (for head azimuth adj.)
VTT-656 (for motor speed, wow flutter adj.)
VTT-664 (for Reference Level 1 kHz)
VTT-675N (for playback frequency response)
6) Resistor 600 2 (for attenuator matching)
or equivalent
2. Mechanical adjustment
1) Torque testing cassette gauge, CTG-N.
2) Blank tape (C-120) for tape running checker.
[li]
Mechanical adjustment
This adjustment is the same as those of the service manual
for PC-3 JW/W/WHIC (No.
1470).
1469) or PC-3L/LB (No.
Please refer to the service manua! of PC-3 JW/W/WH/C
(No. 1469, page 17) or PC-3L/LB (No. 1470 page 17).
[lll] Electrical adjustments location
Main Amp. P.W. Board (parts ass’y side view)
[
L
fa
VRi01
R
L
4
4 ae
x vrto2[ —}— L
s
vr202 |) — R
For
(Tu
of
the
Z
a
VR201
response adj.
playback level ad-
justment
ning in the direction
the arror increases
playback levels.)
- For playback frequency
{Connect/Disconnect)
For recording level
adjustment (Turning
in the direction of
the arrow increases
| the record-
|} ing levels.) ¥R104
VR103
——— Metal
O®
(8) vaaos
Qo
(R) vraos
‘—Normal
[IV] Electrical circuit adjustment procedure
In the steps marked by an asterisk (*), adjustment should
be performed, however, only checking is sufficient with
steps other than those.
3,
For bias current ad-
justment
{Turning in the
direction of the ar-
row increases the
bias current value.)
|
Front
Fig. 8
Adjustment should be performed in the order of steps 1, 2,
Perform this adjustment with the NR SYSTEM
switch set to OFF.
Step
Item
Adjustment
AUBTING
miancard
Remarks
point
value
1*
Playback
Play
back
test
tape
VTT-675N
(1
kHz,
|
C102
Reference
NR
SYSTEM:
OFF
frequency
10
kHz)
for
following
adjustment.
C103
frequency:
TAPE
SELECT:
SF/NORM
response
1.
Connect/Disconnect
C102
or
C103
so
1
kHz
that
10
kHz
signal
and
1
kHz
signal
O+2
dB
gains
become
flat
response.
at
10
kHz
2*
leery
1.
Play
back
the
VTT-664
Reference
tape
|
VR101
—8
dBs
This
adjustment
becomes
necessary
playback
(1
kHz)
with
the
tape
select
switch
set
201
when
a
change
in
playback
level
results
level
to
the
SF/NORM
position.
(for
example,
due
to
head
2.
Adjust
VR101
and
VR201
until
the
replacement).
L
I
LINE
OUT
becomes
about
—8
dBs.
ae.
No. 4209