Transmitter Alignments - Motorola APX 1000 Basic Service Manual

Radio Alignment Procedures: Transmitter Alignments
6.5

Transmitter Alignments

6.5.1 Reference Oscillator Alignment
Adjustment of the reference oscillator is critical for proper radio operation. Improper adjustment will
result not only in poor operation, but also in a misaligned radio that will interfere with other users
operating on adjacent channels. For this reason, the reference oscillator should be checked every
time the radio is serviced, or once a year, whichever comes first. The frequency counter used for this
procedure must have a stability of 0.1 ppm (or better).
NOTE: Reference oscillator alignment is required after replacing (or servicing) the transceiver board.
This test can be done with either the R-2670 Communication Analyzer or the 8901_ Modulation
Analyzer.
• Initial setup using the R-2670 Communication Analyzer:
- RF Control: Monitor
- B/W: WB
- Freq: CPS frequency under test
- Attenuation: 20dB
- Mon RF in: RF I/O
- Meter: RF Display
- Mode: STD
- Input Level: uV or W
- Display: Bar Graphs
- Squelch: Mid-range or adjust as necessary
• Initial setup using the 8901_ Series Modulation Analyzer:
- Press the green Automatic Operation button on the analyzer.
- Press the FREQ key.
- Type 7.1 followed by SPCL button to set the 8901B_ modulation analyzer for maximum
accuracy.
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