DMR oddness?

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mejnetguru

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I'm not all that up on the all the nuances for the variants of DMR but I had something odd happen.

I regularly Spectrum Sweep or Limit Search (using WS-1088 in this case) and normally when I find a DMR station it decodes it fine when (naturally) a transmission is in place, audio is heard fine. When no transmission, nothing hear. Normal.

Took a road trip to Lake Placid area for the holiday. My sweep found the Lake Placid PD which is a single conventional repeater pair running DMR (per the DB). What I heard was full-time digital noise (a CC?, odd for a non-trunked system)?

Programmed the frequency for DMR, no digital noise heard (as expected). But when transmissions occur, audio is clearly voice but very garbled, almost sounds like the older "voice inversion", did not sound like encryption nor did the scanner detect encryption.

So why the full-time digital noise on a non-trunked system when not programmed?
 

RayAir

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The frequent channel activity could be location data on one time slot and voice transmissions occur on the other slot. Can you use DSD+ to look at this signal?

Do the voice transmissions sound like this by chance:
https://youtu.be/ydldYXlSjNY
 

mejnetguru

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I'm not there anymore, so I can't monitor anymore but data on a time-slot would make sense for a PD, maybe GPS data?

Yes, that's the audio. I guess Whistler doesn't identify Basic Privacy as "encryption" correctly.
 

RayAir

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Based on your description that's what I suspected.
As far as encrypted detection the scanner is probably looking for the privacy indicator header.
 
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