Xts radio Alignment

[GearJammersc]

I have a question about the Alignment a xts 3000 and the xts5000,2500. The xts5000 and 2500 tuned with the aeroflex shows the 5000 and 2500 reference oscillator (<100Hz) to pass. Ok for the xts3000 it's (<200Hz). Why is that? I thought for p25 trunking everything was supposed to be less than 100Hz on a type one system. According to the xts3000 service manual vs other xts radios a brand new radio from factory could be plus or minus 750Hz.

 

[wgbecks]

First off, I don't know of a P25 receiver design that specifically spells out that the frequency has to be to maintained within +/- 100 Hz.
Obviously, the XTS 2500/5000 has improved frequency stability over the older XTS3000.

That said, the XTS2500/5000 BSM states to adjust the reference oscillator on 700/800 MHz to +/- 100 Hz, whereby the BSM for the XTS3000
states to adjust the reference oscillator on 800 MHz to +/- 300 Hz.

Generally, the tighter the receiver filtering, the more emphasis must be placed on maintaining tighter frequency tolerances in order to obtain low BER for over the expected range of input signal levels.

As long as you can achieve either of these targets for their respective radios, then they are said to be in adjustment per the manufacturers specifications, and do comply with FCC rules and regulations. My preference is to maintain the tighter tolerance of +/- 100 Hz and retire the
XTS3000 from commercial service.

The XTS3000 has rather limited use for operation on 9600 baud trunking systems. In fact, there was only one firmware release for the XTS3000 that supported 9600 baud trunking, and it was only on 800 MHz models, with only one fix band plan available for the Astro 25 Channel ID assignment.

 

[GearJammersc]

Thanks for the information well said. I have 3000 that was tuned reference oscillator freq error was -81hz afterwords. And a 2500 was tuned with freq error of -7hz. Guess you can't get no better than that.