Motorola PM1200, Basic Service Manual

Page: 46 / 138

October 26, 2007 6880309U09-A
5-4 Radio Alignment and Programming Procedures : Alignment
5.4.3 PLL Reference Frequency
With the wattmeter, dummy load and frequency counter connected to the antenna jack, and select
band center frequency channel, key the transmitter and adjust TC1001 on the Main Unit, if
necessary, so the counter frequency is within ±100 Hz of the channel center frequency for the
transceiver version.
5.4.4 Transmitter Output Power LVHF
1. Select band center frequency channel, and select high power output level.
2. Key the transmitter and adjust by control commands for high power from the computer for
120 ± 2 Watts as indicated on the wattmeter.
3. Select band center frequency channel, and select low power output level.
4. Key the transmitter and adjust by control commands for low power from the computer for
50 ± 1 Watts as indicated on the wattmeter.
5.4.5 Transmitter Deviation
5.4.5.1 Microphone Audio Modulation Level
1. Select band center frequency channel, and adjust the AF generator for 25 mV (-30 dBm)
output at 1 kHz to the microphone jack.
2. Key the transmitter and adjust by control commands for maximum deviation from the
computer for 4.2 kHz ± 0.1 kHz deviation as indicated on the deviation meter.
5.4.5.2 CTCSS Modulation Level
1. Select band center frequency channel, with 151.4 Hz CTCSS encode, and reduce the AF
generator injection to zero.
2. Key the transmitter and adjust by control commands for CTCSS deviation from the computer
for 0.7 kHz ± 0.05 kHz deviation as indicated on the deviation meter.
5.4.5.3 DCS Modulation Level
1. Select band center frequency channel, with DCS 023 enabled, reduce the AF generator
injection to zero.
2. Key the transmitter and adjust by control commands for DCS deviation from the computer for
0.7 KHz ± 0.05 KHz deviation as indicated on the deviation meter.
5.4.6 Receiver
Set up the test equipment as shown for receiver alignment, and construct the audio test adapter as
described:
1. With the transceiver set to band center frequency channel, and the RF signal generator tuned
to the same frequency, set the generator for ± 3.0 kHz deviation with 1 kHz tone modulation,
and set the output level for 1
μ
V at the antenna jack.
2. Adjust by control commands for tune from the computer for optimum SINAD, reducing signal
generator output level as necessary for proper meter deflection.
3. After the previous step, final signal generator level should be less than 0.25
μ
V for 12dB
SINAD.