tti Tech PMR-446, Service Manual, Page: 8 / 34

SECTION 4 ADJUSTMENT PROCEDURES
4-1. GENERAL
For proper alignment, the unit should be programmed with the following channel and frequency information.
RX (MHz) TX (MHz) RX/TX Tone Code
CH01
CH02
CH03
CH04
CH05
CH06
CH07
CH08 446.00625
446.01875
446.03125
446.04375
446.05625
446.06875
446.08125
446.09375 No Tone
No Tone
No Tone
67Hz
100Hz
250.3Hz
627 DCS
No Tone
Make connections to the Unit per Figure 1,2,3,4 (Equipment Test Set-up) below and Figure 5 (Program Jig).
4-2. SYNTHESIZ ER/TRANSMITER
4-2-1. VCO Check
1. Connect the voltmeter to TP1 .
2. Place the Unit on channel 8 (446.09375MHz).
3. Check in Receive mode for 2.2 0.1V at TP1 .
4. Push the PTT switch (TX) and check the voltage at TP1 will less then 3.0V.
4-2-2. Frequency Adjustment
1. Connect the Radio in accordance with Figure 1.
2. Place the Unit on channel 8 (446.09375MHz).
3. Operate the transmitter and adjust CV301 for a Frequency Counter reading within ±100Hz of the programmed
transmits frequency.
4-2-3. Modulation Adjustment
1. Connect the Radio in accordance with Figure 1.
2. Place the Radio on channel 4 (446.04375MHz).
3. Input a signal of 1KHz 300 mV into Program Jig(MIC) from Audio generator.
4. Operate the transmitter, using Program Jig(PTT SW) and adjust RV501 (MOD.ADJ) for ±4.0kHz
for 2.1kHz ~ 2.2KHz deviation.
5. To adjust CTCSS and DCS Deviation, perform step1 though 4 above.
Then set the FM liner detector audio bandwidth of 0.25Hz to 15,000Hz. Turn the de-emphasis function off.
6. Place the Radio on channel 7 (446.08125MHz, TX; 627 DCS CODE).
Set the audio generator output to 0V operate the transmitter, using Program Jig (PTT SW) and adjust the DCS
balance control RV503 to U1-U2 is minimum on the Oscilloscope.
7. Place the Radio on channel 5 (446.05625MHz, TX; 100Hz Tone).
Operate the transmitter , using Program Jig (PTT SW) and adjust RV101 to ±800Hz deviation on Modulation
Analyzer.
446.00625
446.01875
446.03125
446.04375
446.05625
446.06875
446.08125
446.09375
7