10
SECTION 4
ELECTRICAL ADJUSTMENTS
0 dBm = 0.775 V
• Make the set in test mode. (See page 7.)
– TX Adjustments and Checks –
1. TX VCO Check
Setting:
Procedure:
1. Connect a digital voltmeter to TP (TX VCO), TP (RX VCO)
and TP (GND) on the BASE RF board.
2. Check that both TP (TX VCO) and TP (RX VCO) voltage of
digital voltmeter are 0.8 V to 2.2 V.
3. Set the
[DIAL MODE]
switch (S2) to the
[TONE]
position.
4. Press the
[HANDSET LOCATOR]
key (S1) three times to change
the channel to 40CH.
5. Check that both TP (TX VCO) and TP (RX VCO) voltage of
digital voltmeter are 0.8 V to 2.2 V.
6. Press the
[HANDSET LOCATOR]
key (S1) once to change
the channel to 1CH.
7. Check that both TP (TX VCO) and TP (RX VCO) voltage of
digital voltmeter are 0.8 V to 2.2 V.
2. TX Frequency Adjustment
Setting:
Procedure:
1. Connect a frequency counter to TP (ANT) and TP (GND) on
the BASE MAIN board.
2. Restart the test mode to change the channel to 19CH.
3. Adjust CT1 on the BASE MAIN board so that the value of
frequency counter becomes 926.897468 MHz
±
600 Hz.
3. TX Power Adjustment
Setting:
Procedure:
1. Connect a power meter to TP (ANT) and TP (GND) on the
BASE MAIN board.
2. Adjust RT301 on the BASE RF board so that the value of power
meter becomes –5.5 dBm
±
1 dBm.
3. Set the
[DIAL MODE]
switch (S2) to the
[TONE]
position.
4. Press the
[HANDSET LOCATOR]
key (S1) three times to change
the channel to 40CH.
5. Check that the value of power meter is –5.5 dBm
±
1.5 dBm.
6. Press the
[HANDSET LOCATOR]
key (S1) once to change
the channel to 1CH.
BASE UNIT
+
–
digital voltmeter
TP (TX VCO), TP (RX VCO)
TP (GND)
+
–
frequency counter
TP (ANT)
TP (GND)
+
–
power meter
TP (ANT)
TP (GND)
7. Check that the value of power meter is –5.5 dBm ± 1.5 dBm.
4. Modulation Sensitivity Adjustment
Setting:
Procedure:
1. Connect an AF OSC to the LINE jack (J1) on the BASE MAIN
board.
2. Connect a deviation meter to TP (ANT) and TP (GND) on the
BASE MAIN board.
3. Set the
[DIAL MODE]
switch (S2) to the
[PULSE]
position.
4. Press the
[HANDSET LOCATOR]
key (S1) once to change
the test mode step to TX MOD CHECK.
5. Adjust RT3 on the BASE MAIN board so that the value of
deviation meter becomes 8 kHz
±
0.5 kHz.
5. Distortion and S/N Ratio Check
Setting:
Procedure:
1. Connect a distortion meter and noise meter to TP (ANT) and
TP (GND) on the BASE MAIN board.
2. Check that the value of distortion meter is less than 4%.
3. Check that the value of noise meter, and record it.
4. Stop outputting the signal of AF OSC.
5. Check that the value of noise meter again. And check that dif-
ference of level between in step3 and in step5 is less than
30 dB.
AF OSC
1 kHz, –20 dBm
+
–
600
Ω
LINE jack (J1)
+
–
deviation meter
TP (ANT)
TP (GND)
AF OSC
1 kHz, –20 dBm
+
–
600
Ω
LINE jack (J1)
noise meter
CCITT: on
+
–
+
–
distortion meter
TP (ANT)
TP (GND)
