Sony HCD-GT111 Service Manual page 22

HCD-GT111/GT222/GT444/GT555
RF LEVEL CHECK
oscilloscope
CD board
TP123 (RFO)
TP124 (VC)
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. Confi 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.
RF signal waveform
Connecting Location : CD board
– CD Board (Conductor Side) –
22
VOLT/DIV : 200 mV
TIME/DIV : 500 ns
level : 1.3 ± 0.3 Vp-p
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 sig-
nals.
When the selected station signal is received in good condition,
"TUNED" is displayed.