Kenwood RXD-790 Service Manual page 16

RXD-790/V860/V890
4. Cassette Deck adjustment
No ITEM
Unless otherwise specified, set the respective switches as follows:
TAPE : NORMAL
ø . Cassette mechanism unit (Adjustment of the REC / PLAY head)
Demagnetization
<1>
and cleaning
Azimuth of the
<2>
REC/PLAY head
¿ . PC BOARD ADJUSTMENT
TAPE
<1>
SPEED(NORMAL)
¡. PC BOARD ADJUSTMENT
PLAYBACK
<1>
LEVEL
<2> BIAS CURRENT
AC voltmeter
16
ADJUSTMENT
INPUT OUTPUT
SETTING SETTING
DOLBY : OFF PLAY OUT : Lch (X28,CN6 4pin), Rch (X28,CN6 1pin)
–
–
TCC−153
MTT−114 (B)
10kHz, − 10dB
TCC−110
MTT−111
(B)
SCC−1727
3kHz
MTT− 130
(B)
400Hz
(A)
Adjust the AG
for the output of
the DECK to (B)
become 1kHz
-30dBs.
400Hz/10kHz
X28, CN6
1
R OUT
R IN
GND
L OUT
L IN
5
AG
(A)
DECK
ALIGNMENT
SETTING
POINT
Power : OFF Recording
Demagnetiza- head, erase
tion,cleaning, head,capstan
PLAY
pinch roller
PLAY
FWD
A DECK
VR 5
PLAY
B DECK
VR 6
A DECK
VR 7 (L)
VR 8 (R)
PLAY
B DECK
VR 1 (L)
VR 2 (R)
REC
VR 3 (L)
VR 4 (R)
PLAY
AC voltmeter
Oscilloscope
(B)
ALIGN FOR FIG.
0dBs=0.775V
Demagnetize the
REC / PLAY head
with the head eras-
er.Clean the REC /
PLAY head, erase
head,capstan and
pinch roller using a
cotton swab slightly
damped with alcohol.
Adjust the output to
maximum and adjust
the azimuth adjust-
ment screw for the
Lissajours waveform
pattern of the oscillo-
scope to become
RVS
close to a 45°
straight line.
Adjust the tape
speed so that 3kHz
is obtained at the
center of the tape.
Adjust the playback
output to -2.0dBs
Record 1kHz and
10kHz alternately,
and adjust the bias
current adjustment
potentiometer for the
playback levels to
become the same.
Frequency counter