A little help with Unitrunker 2.1.

[ArktiiK]

Let me start by saying I'm very new to this, however I'm pretty tech savvy and I've followed countless guides/videos, but I'm still not having much luck.

I am using a single RTL-SDR V3 dongle.

A lot of your questions will be answered from the screenshots I've posted (System/Site, Freqs, VFO settings). From what I've gathered in my research, DSD+ is no longer necessary with Unitrunker 2.1 (am I wrong?) Either way, with or without DSD+, I'm not hearing anything at all. I noticed that the "Voice" VFO reads as "Parked", which may be a clue as to what's going on.

Interestingly, when I first got the configuration set up with assistance from the RR DB download function, I was able to hear some calls, but not anymore. Do I need a second dongle?

 

[maus92]

Unitrunker 2 does not require DSD+, thus no need to be running the programs concurrently as they appear to be in your screenshots. The RRDB indicates AWIN as a P25 Phase 2 system - note that Unitrunker 2 does not decode P25 Phase 2 (TDMA) audio. However it appears that the system is using Phase 1 signaling. Please post a view of your channels tab to confirm. The larger issue is the channel spread of this site exceeds that bandwidth of a single RTL-SDR device, so you will need to add at least one more physical SDR as only one of the traffic channels (773.66875) is tunable when 774.83125 is being used as the control channel. Also, no need for a virtual cable - output your audio to your computer's default audio output.

 

[ArktiiK]

Unitrunker 2 does not require DSD+, thus no need to be running the programs concurrently as they appear to be in your screenshots. The RRDB indicates AWIN as a P25 Phase 2 system - note that Unitrunker 2 does not decode P25 Phase 2 (TDMA) audio. However it appears that the system is using Phase 1 signaling. Please post a view of your channels tab to confirm. The larger issue is the channel spread of this site exceeds that bandwidth of a single RTL-SDR device, so you will need to add at least one more physical SDR as only one of the traffic channels (773.66875) is tunable when 774.83125 is being used as the control channel. Also, no need for a virtual cable - output your audio to your computer's default audio output.

Thanks for clearing that up! I will be getting a second dongle. I’m assuming that I can use the same antenna with both dongles using a splitter? Is there anything else I might need?

 

[GTR8000]

Correct, you would need 2 dongles to cover that spread, as they are only capable of roughly 2.4 MHz each. With the control channel being 774.83125, at best it could tune down to 772.43125, not nearly low enough to cover the 770.40625 and 771.30625 traffic channels.

You can simply split the signal from the antenna and feed it to both dongles, assuming the signal is strong enough to begin with.

Another option, which will cost a bit more, would be to replace your RTL dongle with an Airspy Mini (currently on sale for $85), in which case the 6 MHz bandwidth of that single dongle will cover the entire site, and you wouldn't have to split the signal. You can then free up your RTL dongle for something else. Either way you're going to be spending around $30-35 for another RTL dongle + whatever it costs you for a splitter/multicoupler and jumpers. Might just be better off investing the $85

 

[dave3825]

I just ordered myself another Airspy mini from Itead. On sale for 5 more days. $4.25 dollar shipping too.

Airspy Official Online Store

Visit the post for more.

itead.cc