Electrical Adjustments; Base Unit Section - Sony SPP-935 Service Manual

4-1. BASE UNIT SECTION

• Make the set in Test Mode (See page 14)
1. TX LOOP VOLTAGE check
Setting:
digital voltmeter
TP4 (TX-LOOP-VOLTAGE)
+
–
GND
Precedure:
• Connect a voltmeter to TP4 (TX-LOOP-VOLTAGE) and GND.
• Check the value of voltmeter is 1.4 ± 0.6 V.
2. TX POWER check
Setting:
level meter
TP (ANT)
+
–
GND
Precedure:
• Connect a level meter to TP (ANT) and GND.
• Check the level of level meter is –5 ± 0.5 dB.
Adjustment Location:
[BASE MAIN BOARD] (SIDE A)
TP
(ANT)
[BASE MAIN BOARD] (SIDE B)
TP3 (RX-LOOP-VOLTAGE)
TP4
(TX-LOOP-VOLTAGE)
SECTION 4

ELECTRICAL ADJUSTMENTS

3. RX LOOP VOLTAGE check
Setting:
Precedure:
• Connect a voltmeter to TP3 (RX-LOOP-VOLTAGE) and GND.
• Check the value of voltmeter is 1.4 ± 0.6 V.
4. QUAD-TUNE VOLTAGE adjustment
Setting:
Precedure:
• Connect a voltmeter to U1 !¢ and GND.
• Adjust C151 so that QUAD-TUNE VOLTAGE is 2.2 ± 0.1 V.
U1
14
C151
U12
U3
F3
– 16 –
digital voltmeter
TP (RX-LOOP-VOLTAGE)
+
–
GND
digital voltmeter
U1 !¢
+
–
GND