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HCD-GT111/GT222/GT444/GT555
22
RF LEVEL CHECK
Procedure :
1. Connect an oscilloscope to TP123 (RFO) and TP124 (VC).
2. Turn the power ON.
3. Load a disc (YEDS-18) and playback.
4. Con
fi
rm that oscilloscope waveform is clear and check if RF
signal level is correct or not.
Note:
Clear RF signal waveform means that the shape “
◊
” can be clearly
distinguished at the center of the waveform.
Connecting Location :
CD board
TP123 (RFO)
CD board
oscilloscope
TP124 (VC)
RF signal waveform
VOLT/DIV : 200 mV
TIME/DIV : 500 ns
level : 1.3 ± 0.3 Vp-p
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. Con
fi
rm “TUNED” is lit on the display for A, B and C sig-
nals.
When the selected station signal is received in good condition,
“TUNED” is displayed.
TUNER SECTION
TP106 (FE)
IC101
TP123 (RFO)
TP124 (VC)
– CD Board (Conductor Side) –