DMR in Central VA

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BlueMoon2

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Hi Guys,

I posted this over in the DSD and DMR decoding, but they eventually referred me over here. I have a RTL-SDR dongle that I have "decoding" digital data but not voice data. I am trying to listen to the Jaunt Mototrbo system and other frequencies that have come up on my spectrum for SDR#. I am running SDR# and DSD plus together and you will see below what I'm getting. My question is if a DMR system is running data and voice on the same frequency, I should be able to hear it using these software programs and the right setup right?
 

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EricCottrell

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Hello,

Brief transmissions of idle data are used by repeaters in different locations connected together. It acts like a beacon and radios use it to determine which repeater site has a usable signal.

There are two timeslots, or virtual channels that can transmit voice or data. There is data sent before, during, and after a voice transmission that has the talkgroup, radio id, and other information. DSDPlus can decode this data.

It appears you are getting good decoding and should hear voice when it appears. A lot of business systems are only active during the 9 to 5 workday.

73 Eric
 

W4UVV

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Prince George, Virginia--Central Va.
Jaunt/Cavalier Communications trs

You may already know but In case you don't the 462.0375 mhz. frequency shown in your post is one of 5 analog/MOTOTRBO trs frequencies licensed to Cavalier Communications (WQBP750) operating at its' Carter Mtn. site. The other trs frequencies are: 451.9250, 452.5000, 461.4875 and 463.6875 mhz. Iding the various trs users heard on the different trs frequencies is another matter.

You won't hear data. You will hear unencrypted voice transmissions. I recommend using a computer external audio system with a good treble/bass adjustment range as MOTOTRBO audio to me seems bassey. Using DSD Plus, immediately prior to a voice transmission "VOICE header" displays. My experience monitoring DMR signals is you must have patience. Many licensees do not transmit frequently. Others such as medical transports, shuttle buses like at VCU in Richmond do transmit frequently. As previously posted weekends are not a good time to monitor. However, if Jaunt is a 24/7 manufacturer they may have frequent comms and be easier to id on the weekend due to fewer trs user's comms.

My two DMR DSD receive system configurations in part use discriminator tapped R7000 analog receivers for monitoring two frequency Capacity Plus systems. I also tested using a SDR dongle for DMR reception but its' RF sensitivity was unacceptable for my reception needs. But for others it is fine to use. You probably can see Carter Mtn. if in the general Charlottesville area so good reception is not an issue. Good luck.

John
W4UVV
 

GmanX

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You probably wont hear much on the Cavalier Comm DMR repeaters. I think one frequency is purely analog. Mostly Boars Head Inn traffic
 
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