Electrical Adjustments; Base Unit Section - Sony SPP-SS964 Service Manual

6-1. BASE UNIT SECTION

• Make the set in Test mode (see page 16)
1. Checking RX I & Q Output Level
Setting:
oscilloscope
level meter
+ +
– –
SSG
Procedure:
1. Place the base unit in the Continuous Receive mode (CH1,
LNA ON, AGC ON).
2. Set the SSG frequency to the frequency on CH1 + 300 kHz,
and the RF output level to –95 dBm.
3. Measure the output level of RXIN, RXIP, RXQN and RXQP
with a level meter. At this time, confirm with an oscilloscope
that a sine wave of 300 kHz is output.
4. Confirm that the measured output level is –31.0 to –24.0
(TYPICAL –27.0) dBV. If IC951 was replaced (there is no ID
data), the output level is –31.0 to –24.0 dBV.
5. Also, execute steps 1 through 4 for the channels 10 and 20.
* For the frequency on each channel, see page 13.
2. Checking TX Center Frequency
Setting :
• short: TP918 ↔ TP919
frequency counter
+
–
Procedure:
1. Short TP918 and TP919 (GND) on the BASE MAIN board in
the base unit.
2. Place the base unit in the Continuous Transmit mode (CH1,
High power).
3. Measure the ANT OUT frequency of the RF module in the
base unit using a frequency counter.
4. Confirm that the measured frequency is 903.600 MHz ±
27 kHz.
5. Also, execute steps 1 through 4 for the channels 10 and 20.
SECTION 6

ELECTRICAL ADJUSTMENTS

TP906: RXIP
TP905: RXIN
TP904: RXQP
TP903: RXQN
TP919: GND
ANTENNA TERMINAL
ANTENNA TERMINAL
3. Checking TX Output
Setting:
peak power meter
+
–
Procedure:
1. Place the base unit in the Continuous Transmit mode (CH1,
High power).
2. Measure the ANT OUT output of the RF module in the base
unit using a peak power meter.
3. Confirm that the measured output is 80 mW (MIN 30 mW).
4. Also, execute steps 1 through 4 for the channels 10 and 20.
CH10: 80 mW (MIN 30 mW)
CH20: 75 mW (MIN 25 mW)
– 20 –
ANTENNA TERMINAL