NH SP P25 on PSR-500 Questions

[ech1253]

Hello...

While driving through NH yesterday, I had the NHSP VHF-Hi P25 Troop Dispatch frequencies programmed (as CONV objects) with modulation set to "auto" and the squelch type set to "P25" and squelch code set as "search". I was able to monitor both sides of conversations with good audio quality, BUT about 50% of the time I saw 5x5 signal strength, and the modulation displayed as "dg", and the known NAC code was shown, NO audio...

Thinking I was missing conversation I should be able to hear (full signal, digital mod, known NAC), I tried enabling/disabling all AGC, SuperTrack combinations to no avail. Then when I got home I decided to confirm the NHSP freqs on RR and noticed that NHSP MDT units transmit on the same frequency (and apparently use the same NAC!?!)

http://www.radioreference.com/apps/db/?aid=1233

So here is my question:

Is there any other way to keep the scanner from stopping on an MDT transmission on such shared frequencies if both talking and MDT use the same NAC? (granted, during MDT no audio is heard, but the unit is still paused for the duration...)

Has anyone encountered this and found a work-around?

Any thoughts are, as always, very much appreciated.

EDIT: I am assuming that what I observed above are not "encrypted" transmissions, as I have heard those on other systems and noticed that the audio is unmuted (and unintelligible)...

Ed

 

[DaveIN]

I don't think you can do anything if it uses the same NAC for voice and data on P25.

 

[ecps92]

Check the NH Forum, there was talk that the NHSP also use the Voice Channels for Data and that is probably what you saw occuring
and there was no work around.

Hello...

While driving through NH yesterday, I had the NHSP VHF-Hi P25 Troop Dispatch frequencies programmed (as CONV objects) with modulation set to "auto" and the squelch type set to "P25" and squelch code set as "search". I was able to monitor both sides of conversations with good audio quality, BUT about 50% of the time I saw 5x5 signal strength, and the modulation displayed as "dg", and the known NAC code was shown, NO audio...

Thinking I was missing conversation I should be able to hear (full signal, digital mod, known NAC), I tried enabling/disabling all AGC, SuperTrack combinations to no avail. Then when I got home I decided to confirm the NHSP freqs on RR and noticed that NHSP MDT units transmit on the same frequency (and apparently use the same NAC!?!)

http://www.radioreference.com/apps/db/?aid=1233

So here is my question:

Is there any other way to keep the scanner from stopping on an MDT transmission on such shared frequencies if both talking and MDT use the same NAC? (granted, during MDT no audio is heard, but the unit is still paused for the duration...)

Has anyone encountered this and found a work-around?

Any thoughts are, as always, very much appreciated.

EDIT: I am assuming that what I observed above are not "encrypted" transmissions, as I have heard those on other systems and noticed that the audio is unmuted (and unintelligible)...

Ed