Electrical Adjustments; Base Unit - Sony SPP-ID300 Service Manual

3.

ELECTRICAL ADJUSTMENTS

0 dBm = 0.775 V

BASE UNIT

• Make the set in test mode. (See page 3)
– TX Adjustment and Check –
1. TX VCO Adjustment
Setting:
digital voltmeter
+
–
Procedure:
1. Connect a digital voltmeter to TP (TX VCO) and TP (GND).
2. Adjust L10 so that the value of digital voltmeter becomes 2.7
±0.05 V (SPP-ID300) or 2.8 ±0.05 V (SPP-ID400) .
2. Power Check
Setting:
power meter
+ TP (ANT)
–
TP (GND)
Procedure:
1. Connect a power meter to TP (ANT) and TP (GND).
2. Check that the value of power meter is 7.5 ±3 dBm.
3. Frequency Check
Setting:
frequency counter
+
–
Procedure:
1. Connect a frequency counter to TP (ANT) and TP (GND).
2. Check that the value of frequency counter is 46.77 MHz ±1.2
kHz.
4. RX VCO Adjustment
Setting:
digital voltmeter
+
–
Procedure:
1. Connect a digital voltmeter to TP (RX VCO) and TP (GND).
2. Adjust L7 so that the value of digital voltmeter becomes 1.3
±0.05 V.
TP (TX VCO)
TP (GND)
TP (ANT)
TP (GND)
TP (RX VCO)
TP (GND)
5. Modulation Sensitivity Check
Setting:
AF OSC
+
+
– –
deviation meter
+
–
Procedure:
1. Connect an AF OSC to the LINE jack (J1).
2. Connect a deviation meter to TP (ANT) and TP (GND).
3. Set the [DIAL MODE] switch (S1) to the [P] (PULSE) position
(SPP-ID300) .
4. Press the [PAGE] key (S4) to change the test mode step to TX
MODE CHECK. (SPP-ID300)
Press the [SPEAKERPHONE] key (S2) to change the test mode
step to TX MODE CT PASS. (SPP-ID400)
5. Check that the value of deviation meter is ±2.25 kHz to ±3.95
kHz.
6. Data Deviation Check
Setting:
deviation meter
+
–
Procedure:
1. Press the [PAGE] key (S4) to change the test mode step to TX
DATA1. (SPP-ID300)
Press the [SPEAKERPHONE] key (S2) twice to change the test
mode step to TX DATA. (SPP-ID400)
2. Check that the value of deviation meter is ±3.75 kHz to ±6.75
kHz.
7. Channel Change Check
Setting:
frequency counter
+
–
Procedure:
1. Connect a frequency counter to TP (ANT) and TP (GND).
2. Set the [DIAL MODE] switch (S1) to the [T] (TONE) position.
(SPP-ID300)
3. When press the [PAGE] key (S4) (SPP-ID300) or the
[INTERCOM] key (S3) (SPP-ID400) , check that the frequency
of frequency counter (channel) is changed each time the key is
pressed, and CHARGE LED lights up for 300 msec.
– 7 –
600 Ω
ATT
LINE jack
+
(J1)
–
1 kHz, –20 dBm
TP (ANT)
TP (GND)
TP (ANT)
TP (GND)
TP (ANT)
TP (GND)