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ADJUSTMENT PROCEDURE
Step Adjustment
Test
Point Procedure
1 L44
VHF
Receive
TP1
1. Connect digital voltmeter to TP1 on RF PCB.
2. Set VHF CH01.
3. Adjust L44.
4. TP1 voltage 1.2~1.6V DC.
2
L46 VHF Transmit TP1
1. Connect a digital voltmeter to TP1 on RF PCB.
2. Set VHF CH01.
3. Adjust L46.
4. TP1 voltage 1.2~1.6V DC.
3 L45
UHF
Receiver
TP2
1. Connect a digital voltmeter to TP2 on RF PCB.
2. Set UHF CH01.
3. Adjust L45.
4. TP1 voltage 1.2~1.6V DC.
4 VC1
1. Connect the antenna coupler output to a frequency counter.
2. Set channel to VHF CH01 (156.050 MHz).
3. Adjust VC1 to obtain a frequency reading 156.050 MHz
±
200Hz.
5
VR2 UHF
Modulation
1. Connect the antenna coupler output to an FM linear detector.
2. Connect Audio Oscillator to Microphone Jack.
3. Set unit to transmit mode.
4. Set audio oscillator output to -23dBm 1 kHz.
5. Adjust VR2 to obtain
±
2.3 kHz deviation.
6
VR3 VHF
Modulation
1. Connect the antenna coupler output to an FM linear detector.
2. Connect Audio Oscillator to Microphone Jack.
3. Set unit to transmit mode.
4. Set audio oscillator output to -23dBm 1 kHz.
5. Adjust VR3 to obtain
±
4.5 kHz deviation.
10
Summary of Contents for MR HH425 LI VP
Page 7: ...BLOCK DIAGRAM BACKLIGHT BACKLIGHT 7 ...
Page 11: ...Main PCB Top View Bottom View VR3 VR2 VC1 L44 L46 SQL L45 11 ...
Page 12: ...WIRING DIAGRAM CHARGER CHARGER 12 ...
Page 13: ...Main PCB Top View PRINTED CIRCUIT BOARD SQL 13 ...
Page 14: ...Main PCB Bottom View PRINTED CIRCUIT BOARD 14 ...
Page 15: ...Charger PCB PRINTED CIRCUIT BOARD Top View Bottom View LCD PCB Bottom View Top View 15 ...
Page 18: ...MAIN UNIT EXPLODED VIEW 18 ...
Page 19: ...CHARGER UNIT EXPLODED VIEW 19 ...
Page 20: ...BATTERY TRAY UNIT EXPLODED VIEW 20 ...
Page 48: ...U4 9032 HT D 48 ...
Page 49: ...U5 M38C29FFAHP60K 49 ...
Page 50: ...2 1 3 1 VOUT 2 VSS 3 VIN Delay Circuitry Vref VSS VOUT VIN U6 XC61FC4012MR U7 U8 U9 NJM324 50 ...
Page 51: ...1 2 3 4 8 7 6 5 A0 A1 A2 GND VCC WP SCL SDA U AT C N 11 24 16 U12 XC6204B502MR 51 ...