Handset Section - Sony SPP-935 Service Manual

4-2. HANDSET SECTION

• Make the set in test mode (See page 15)
1. TX LOOP VOLTAGE check
Setting
digital voltmeter
J2 (TX-LOOP-VOLTAGE)
+
–
J2 (GND)
Precedure:
• Connect a voltmeter to J2 (TX-LOOP-VOLTAGE) and J2
(GND).
• Check the value of voltmeter is 0.8 ± 0.4 V.
2. TX POWER check
Setting:
level meter
TP (ANT)
+
–
J2 (GND)
Precedure:
• Connect a level meter to TP (ANT) and J2 (GND).
• Check the level of level meter is –5 ± 2.5 dB.
Adjustment Location:
[HAND MAIN BOARD] (SIDE A)
TP (ANT)
3. RX LOOP VOLTAGE check
Setting:
frequency counter
Precedure:
• Connect a frequency counter to J2 (RX-LOOP-VOLTAGE) and
J2 (GND).
• Check the value of voltmeter is 0.8 ± 0.4 V.
4. QUAD-TUNE VOLTAGE adjustment
Setting:
digital voltmeter
Precedure:
• Connect a voltmeter to J2 (RX AUDIO) and J2 (GND).
• Adjust C87 so that QUAD-TUNE VOLTAGE is 1.2 ± 0.075 V.
(RX-LOOP-VOLTAGE)
(TX-LOOP-VOLTAGE)
J2
U1
(RX AUDIO)
(GND)
C87
– 17 –
J2 (RX-LOOP-VOLTAGE)
+
–
J2 (GND)
J2 (RX AUDIO)
+
–
J2 (GND)
U7
U3
U5
U11