HCD-GTR88
16
SECTION 5
ELECTRICAL ADJUSTMENTS
FM TUNE LEVEL CHECK
Procedure:
1. Turn the power on.
2. Input the following signal from signal generator to FM antenna
input directly.
* Carrier frequency : A = 87.5 MHz, B = 98 MHz, C = 108 MHz
Deviation
: 75 kHz
Modulation
: 1 kHz
ANT input
: 35 dBu (EMF)
Note:
Use 75 ohm coaxial cable to connect signal generator and the set.
You cannot use video cable for checking.
Use signal generator whose output impedance is 75 ohm.
3. Set to FM tuner function and tune A, B and C signals.
4. Confi rm “TUNED” is lit on the display for A, B and C signals.
When mark of “TUNED” means “The selected station signal is
received in good condition.”
(For African model only)
1. Demagnetize the record/playback head with a head demagne-
tizer.
2. Do not use a magnetized screwdriver for the adjustments.
TEST TAPE
Tape
Signal
Used for
P-4-A063
6.3 kHz, -10 dB
Azimuth Adjustment
RECORD/PLAYBACK HEAD AZIMUTH ADJUSTMENT
Procedure:
1. Mode: Playback
set
MIC board
PHONES jack
(J702)
+
–
level meter
test tape
P-4-A063
(6.3 kHz,
10 dB)
TUNER SECTION
FM signal generator
OUT (75
Ω
)
SET
DECK SECTION
0dB = 0.775V
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
Screw
position
L-CH
peak
within
1 dB
Output
level
L-CH
peak
R-CH
peak
within
1 dB
Screw
position
R-CH
peak
3. Mode: Playback
set
test tape
P-4-A063
(6.3 kHz,
10 dB)
oscilloscope
V
H
waveform of oscilloscope
in phase 45
q
90
q
135
q
180
q
good
wrong
MIC board
PHONES jack
(J702)
4. After the adjustments, apply suitable locking compound to the
pats adjusted.
Adjustment Location: Record/Playback/Erase Head