Sony SPP-ID300 Service Manual page 8

– 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. Check that the value of digital voltmeter is 1.3 ±0.1 V
2. DISCRI Coil Adjustment
Setting:
SSG
Carrier frequency: 49.83 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. Set the [DIAL MODE] switch (S1) to the [P] (PULSE) position.
(SPP-ID300)
4. Press the [PAGE] key (S4) three times to change the test mode
step to RX ADJ. (SPP-ID300)
Press the [SPEAKERPHONE] key (S2) four times to change the
test mode step to RX ADJ TXB ON. (SPP-ID400)
5. Adjust L3 so that the value of noise meter becomes maximum.
3. TEL Out Level Adjustment
Setting:
noise meter
600 Ω
+
–
Procedure:
1. Connect a noise meter to the LINE jack (J1) .
2. Adjust RT2 so that the value of noise meter becomes –3.5 ±0.5
dBm.
TP (RX VCO)
TP (GND)
TP (ANT)
TP (GND)
TP (DISC)
TP (GND)
LINE jack
(J1)
4. Sensitivity Adjustment
Setting:
Carrier frequency: 48.76 MHz
Modulation: 1 kHz, ± 3 kHz deviation
Output level: 20 dB µ EMF
SINAD meter
Procedure:
1. Connect a SINAD meter and level meter to the LINE jack (J1).
2. Change the output level of SSG to 20 dBµ EMF.
3. Change the carrier frequency of SSG to 48.76 MHz.
4. Set the [DIAL MODE] switch (S1) to the [T] (TONE) position
(SPP-ID300) .
5. Press the [PAGE] key (S4) (SPP-ID300) or the [INTERCOM] key
(S3) (SPP-ID400) four times to change the channel to 11CH.
6. Adjust L6 to get maximum reading on the SINAD meter.
7. Check that the value of level meter is more than 12 dB.
8. Change the output level of SSG to 5 dBµ EMF.
9. Adjust L6 to get maximum reading on the SINAD meter.
10. Check that the value of level meter is more than 12 dB.
11. Change the frequency of SSG to 49.5 MHz.
12. Press the [PAGE] key (S4) (SPP-ID300) or the [INTERCOM] key
(S3) (SPP-ID400) to change the channel to 25CH.
13. Check that the value of level meter is more than 12 dB.
5. RSSI ON/OFF Level Check
Setting:
Carrier frequency: 49.83 MHz
Modulation: off, ± 0 kHz deviation
Output level: 15 dB µ EMF
Procedure:
1. Change the carrier frequency of SSG to 49.83 MHz.
2. Change the modulation of SSG to OFF (±0 kHz deviation).
3. Change the output level of SSG to 15 dBµ EMF.
4. Set the [DIAL MODE] switch (S1) to the [P] (PULSE) position
(SPP-ID300) .
5. Press the [PAGE] key (S4) three times (SPP-ID300) or the
[SPEAKERPHONE] key (S2) twice (SPP-ID400) to change the
test mode step to RSSI CHECK.
6. Check that the CHARGE LED (D11) lights up.
7. Change the output level of SSG to 3 dBµ EMF.
8. Check that the CHARGE LED (D11) goes off.
– 8 –
SSG
TP (ANT)
TP (GND)
600 Ω
+
LINE jack
–
(J1)
level meter
+
–
SSG
TP (ANT)
TP (GND)