Batboard

A friend of mine purchased a used VHF Quantar and last week we were putting the final touches on it at the site and for some reason or another it won't recognize or pass P25. The RX light only works when analog is present and it has recent V 20.xx.xx firmware in it. In addition it is programmed for digital CS and we are just stumped.

Any ideas?
Mark

In the Quantar RSS, under F2 "Service, F2 "Hardware Configuration", be sure the station type is set to "Astro CAI capable".

If it is set to "Astro capable", you won't have the right choice available on the channel programming screen.

That's under F4 "Change View", then "Channel Information" where you can pick "Analog / Astro CAI"

I double checked the cp with what you advised and they are set correctly to include NAC $F7E in the Access Code table.
Very wierd as I stared at this cp a good dozen times and it all looks fine. Grrrrrr....

The next thing I would do is run a receive BER test.

Using the RSS, first read the station's codeplug. Next, goto F2 - "Service", then F3 - "Alignment"

Step down to "Project 25 Rx BER And RSSI Report". Set your service monitor to generate the P25 1011 Hz. pattern at somewhat above normal Rx sensitivity - say about -110 dBm. Then access disable the station and perform the alignment.

The RSS screen should display a dBm level close to what your generator is set for. The BER display should be near 0%. Slowly decrease the generate level a dB at a time as you watch the station report the BER. On a VHF station you will probably go below -120 dBm before the BER starts to rise.

You should also try the 5% error calibration pattern. Your station should report very close to 5% BER at RF levels above threshhold, say -115 dBm or above.

If the station checks out OK - look harder at the codeplug. If it fails - it's broken!

If the Quantar is over two years old, it probably just treats NAC F7E as a regular NAC. You might try reprogramming it to 293 or whatever your radios are programmed to transmit. You could also set it for Digital CSQ, but that would force the TX NAC to 293.

As with the ASTRO-25 XTS/XTL2500/5000 radios, the special "hear all" NAC F7E wasn't supported until just a couple of years ago. The older astro radios (XTS3000, etc.) never supported F7E as a "hear all" NAC, and probably never will.

515 wrote:If the Quantar is over two years old, it probably just treats NAC F7E as a regular NAC. You might try reprogramming it to 293 or whatever your radios are programmed to transmit.

That is exactly what it was. I set it for 293/293 and it worked just fine. Thanks to everyone for their comments.

Mark

Do Quantars do narrowband?

Nexrad16 wrote:Do Quantars do narrowband?

12.5 spacing 2.5kHz deviation. I think that's as narrow as they go.