Electrical Check - Sony HCD-GTR33 Service Manual

HCD-GTR33/GTR55/GTR77
TUNER SECTION
FM TUNE LEVEL CHECK
signal
generator
set
Procedure:
1. Turn on the set.
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 the selected station signal is received in good condition,
"TUNED" is displayed.
DECK SECTION
(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
P-4-A063 6.3 kHz, -10 dB
RECORD/PLAYBACK HEAD AZIMUTH ADJUSTMENT
Procedure:
1. Mode: Playback
test tape
MIC board
P-4-A063
PHONES jack
(6.3 kHz, 10 dB)
(J702)
set
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.
within
L-CH
1 dB
peak
Output
level
R-CH
peak
Screw
position
L-CH
peak
14
SECTION 5

ELECTRICAL CHECK

0dB = 0.775V
Used for
Azimuth Adjustment
level meter
+
–
within
1 dB
Screw
position
R-CH
peak
3. Mode: Playback
test tape
MIC board
P-4-A063
PHONES jack
(6.3 kHz, 10 dB)
(J702)
set
waveform of oscilloscope
in phase 45 90
good
4. After the adjustments, apply suitable locking compound to the
pats adjusted.
Adjustment Location: Record/Playback/Erase Head
oscilloscope
V H
135 180
wrong