Fisher CR-9030 - Page 9

CASSETTE DECK ADJUSTMENT
BEFORE ADJUSTMENT
If the tape surface which contacts the head, the capstan, the
pinch roller, etc., is stained, it will cause unstable running of
the tape, wow and flutter, imperfect recording and erasing,
deterioration of tonal quality, and even tape jam around the
capstan, etc. Occasionally clean each part as follows;
1.
2.
3.
Cut off power.
Open the cassette lid.
Wipe the head, the capstan, and the pinch roller with a
cotton swab. If they are excessively stained, clean them
with a swab soaked in absolute alcohol or cleaning liquid
available on the market.
MEASURING INSTRUMENTS REQUIRED
Dualtrace Oscilloscope
AC VTVM (AC voltmeter with high impedance)
Dummy Load (47kQ)
_ Frequency Counter
Signal Oscillator
Test Tapes
+ 12.5kHz Test Tape (Example: A.BEX TCC-154) for
Azimuth Adjustment
+ 3kHz Test Tape (Example: TEAC MTT-111) for Tape
Speed Adjustment
+ 400Hz Test Tape (Example: TEAC MTT-150) for Play-
back sensitivity Adjustment
Test Tape for Recording and Playback Operations
t+ Metal Tape (Example: TDK AC 712)
t CrO2 Tape (Example: TDK AC 513)
+ Normal Tape (Example: TDK AC 223)
SWITCH POSITIONS
Unless especially indicated, set each switch as follows;
BAAN CE ccce te creseicnodiursaxvet stess otaouscsieeeotccauaneunueies CENTER
PINT LE VEU vissntciia cee dass guyss ceosaiaasencdineteesindedeseieracussiais: MAX
MPA FILTER SWUGIN i cceesrint tes Sansvaceiptateasbacynegadet easteucnucts OFF
DOUBY: NR SWHC Iss: Goeccctacscesasgvsuacusgaeessteeoiasucnsustisenuseseave OFF
sisid asia Heb Sanspumal eeueaueeae Sots ewe aaniaoeduieuioraadoarets ON
TAPE SPEED ADJUSTMENT
ue
2.
3.
Connect the dummy load (47kQ) and the frequency
counter to the LINE OUT terminal L.
Load a test tape (Example: TEAC MTT-111) and set it in
the playback mode.
Adjust potentiometer in the capstan motor so that the
output becomes 3000Hz + 5Hz.
HEAD AZIMUTH ADJUSTMENT
ie
2.
3.
Connect the dummy load (47kQ) and the dualtrace oscil-
loscope to the LINE OUT terminals L and R.
Load a test tape (Example: A.BEX TCC-154) and set it in
the playback mode.
Adjust the head azimuth adjustment screw, so that the
waveforms become maximum on the oscilloscope and
the right wave form overlaps with the left one.
PLAYBACK SENSITIVITY ADJUSTMENT
As
2.
Connect the AC VTVM to the test terminal PB OUT (L) to
GND and PB OUT (R) to GND.
Load a test tape (Example: TEAC MTT-150) and set it in
the playback mode.
“a0;
Adjust
P101,
so
that
the
output
of
test
terminal
(775MV,
L)
becomes
775mV.
Adjust
P102,
so
that
the
output
of
test
terminal
(775MV,
R)
becomes
775mvV.
HX PRO DRIVE TRANS ADJUSTMENT
1.
2.
RECORD BIAS ADJUSTMENT
1.
Load
a
METAL
tape
(Example:
TDK
AC
712)
and
set
it
in
the
Rec.
mode.
Connect
AC
VTVM
to
the
test
terminal
DTS
AJT
(L)
to
GND
and
DTS
AJT
(R)
to
GND.
Adjust
L101,
so
that
the
output
voltage
of
DTS
AJT
(L)
becomes
minimum
level.
|
Adjust
L102,
so
that
the
output
voltage
of
DTS
ADT
(R)
becomes
minimum
level.
Connect the low frequency oscillator to the L side of the
LINE
IN
terminal,
and
the
dummy
load
(47kQ)
and
AC
VTVM to the L side of the LINE OUT terminal.
Load a CrO2 tape (Example: TDK AC 513) and set it in the
recording mode.
Set the input level volume control to the maximum posi-
tion and set the record balance volume control to the
center position.
Feed the signals of 1kHz and 14kHz at 7mV (—43dBs)
from the frequency generator into the unit. Then, record
the signals on the tape.
Play back the recorded signals and adjust P107, so that
the difference between output of the 1kHz and 14kHz
signals reaches +0.5dB.
Adjust P108 for the R side by following the same proce-
dures as described for the L side.
Load a METAL tape (Example: TDK AC 712) and set it in
the recording mode.
Adjust P103 (L) and P104 (R) following the same proce-
dures as for CrO2 tape adjustment.
Load a NORMAL tape (Example: TDK AC 223) and set it
in the recording mode.
Adjust P301 (P301 is common adjustment of L and R.) ~~
following the same procedures as for CrO2 tape adjust-
ment.
METER SENSITIVITY ADJUSTMENT
1.
2:
Connect the low frequency oscillator to the L side of the
LINE IN terminal.
Feed a signal of 1kHz at 100mV (—20dBs) from the fre-
quency generator into the unit. Then, adjust INPUT LEVEL
volume so that test terminal (775MV) becomes 775mvV.
Connect the AC VTVM to the test terminal METER (L) to
GND and METER (R) to GND.
Adjust P105, so that the output of METER (L) becomes
2.4V.
Adjust P106, so that the output of METER (R) becomes
2.4V.