Sony SPP-ID300 Service Manual page 11

– RX Adjustment and Check –
1. RX VCO Voltage Check
Setting:
digital voltmeter
+
–
Procedure:
1. Connect a digital voltmeter to TP (RX VCO) and TP (GND).
2. Press [1] key to change the test mode step to VCO/TX FREQ.
ADJ.
3. Check that the value of digital voltmeter is 1.3 ±0.1 V.
2. DISCRI Coil Adjustment
Setting:
SSG
Carrier frequency: 46.77 MHz
Modulation: 1 kHz, ± 3 kHz deviation
Output level: 66 dB µ EMF
noise meter
+
–
Procedure:
1. Connect a SSG to TP (ANT) and TP (GND) .
2. Connect a noise meter to TP (DISC) and TP (GND) .
3. Press the [4] key to change the test mode step to RX ADJ.
4. Adjust L502 so that the value of noise meter becomes
maximum.
3. Speaker Output Level Adjustment
Setting:
SSG
Carrier frequency: 46.77 MHz
Modulation: 1 kHz, ± 3 kHz deviation
Output level: 66 dB µ EMF
noise meter
+
–
Procedure:
1. Disconnect the speaker (SP801) , and connect a noise meter to
J502.
2. Adjust RT501 so that the value of noise meter becomes 80 ±5
mV.
TP (RX VCO)
TP (GND)
TP (ANT)
TP (GND)
TP (DISC)
TP (GND)
TP (ANT)
TP (GND)
150 Ω
J502 pin 1
J502 pin 2
4. Sensitivity Adjustment
Setting:
Carrier frequency: 46.97 MHz
Modulation: 1 kHz, ± 3 kHz deviation
Output level: 20 dB µ EMF
SINAD meter
Procedure:
1. Change the carrier frequency of SSG to 46.97 MHz.
2. Change the output level of SSG to 20 dBµ EMF.
3. Connect a SINAD meter and level meter to J502.
4. Press the [CHANNEL] key three times to change the channel to
10CH.
5. Adjust L510 to get maximum reading on the SINAD meter.
6. Check that the value of level meter is more than 12 dB.
7. Change the output level of SSG to 4 dBµ EMF.
8. Adjust L510 to get maximum reading on the SINAD meter.
9. Check that the value of level meter is more than 12 dB.
10. Adjust L501 to get maximum reading on the SINAD meter.
11. Check that the value of level meter is more than 12 dB.
12. Change the frequency of SSG to 43.72 MHz.
13. Press the [CHANNEL] key three times to change the channel to
11CH.
14. Adjust L501 to get maximum reading on the SINAD meter.
15. Check that the value of level meter is more than 12 dB.
16. Change the frequency of SSG to 44.48 MHz.
17. Press the [CHANNEL] key three times to change the channel to
25CH.
18. Check that the value of level meter is more than 12 dB.
19. Change the frequency of SSG to 46.77 MHz.
20. Press the [4] key to change the channel to 6CH.
21. Check that the value of level meter is more than 12 dB.
22. Change the frequency of SSG to 44.16 MHz.
23. Press the [CHANNEL] key to change the channel to 18CH.
24. Check that the value of level meter is more than 12 dB.
– 11 –
SSG
TP (ANT)
TP (GND)
150 Ω
+ J502 pin 1
–
J502 pin 2
level meter
+
–