February 3, 2003 6881076C20-E
6-14 Radio Alignment Procedure: ASTRO Digital Spectra and Digital Spectra Plus Tuner Software
6.3.1 Radio Information
Figure 6-12 shows a typical Radio Information screen. All of the data appearing here is informational 
and cannot be changed..
Figure 6-12.  Radio Information Screen
6.3.2 Reference Oscillator Alignment
Reference oscillator alignment is required after replacing (or servicing) the transceiver board.
Radios are shipped from the factory with a worst-case frequency error of ±200 Hz for VHF, ±300 Hz 
for UHF, and ±500 Hz for 800 MHz. These specifications are tighter than the more stringent FCC 
requirements of 1.5 ppm for all bands.
For radios that have been in storage for over six months from the factory ship date, the reference 
oscillator should be checked when the radio is initially deployed to the field. It is strongly 
recommended that the reference oscillator be checked every time the radio is serviced or at least 
once a year, whichever comes first.
The crystal contained in the reference oscillator naturally drifts over time due to its aging 
characteristic. Periodic (annual) adjustment of the reference oscillator is important for proper radio 
operation.
Improper adjustment can result in both poor performance and interference with other users operating 
on adjacent channels.
This test can be done with either the R-2670 Communication Analyzer or the 8901_ Modulation 
Analyzer.
•  Initial set up using the R-2670 Communication Analyzer:
- RF Control: MONITOR
- B/W: WB
- Freq: RSS frequency under test