SDRTrunk SDTRUNK ISSUE With a Channel NTIRN NRHW

[graphton]

I have Setup SDRTrunk and its appears to be working fine. However I have created a channel using The Radio Reference for TEXAS, TARRANT, and chose North Texas Interoperable Radio Network (NTIRN) imported all the Talkgroups into an alias and i have set to only play the "Combined Dispatch Layer 2) with the aliases with NRHW (North Richland Hills, Watauga, and Haltom City). I am seeing transmissions for all the "Muted" aliases but have yet to hear any from NRHW. I can not figure out why its silent. You can see I am receiving the muted traffic but not a peep from what I actually want to hear. Any ideas? I have turned on recordings to see if I was just missing it but no recordings at all.

 

[dave3825]

I am seeing transmissions for all the "Muted" aliases but have yet to hear any from NRHW.

It will show you all activity regardless of if it's set to mute or not.

You pic is showing a bunch of channel start rejections.

What dongle and how many are you using? If your scanning Northeast Tarrant site and using the 1 basic sdr dongle, that yields about 2.4Mhz, you do not have enough dongle to cover that site's freqs since they span 4.45Mhz.

 

[graphton]

It will show you all activity regardless of if it's set to mute or not.

You pic is showing a bunch of channel start rejections.

What dongle and how many are you using? If your scanning Northeast Tarrant site and using the 1 basic sdr dongle, that yields about 2.4Mhz, you do not have enough dongle to cover that site's freqs since they span 4.45Mhz.

i have this:



So you just install different dongles and then assign them to a frequency range? how do you chain them together?

 

[dave3825]

Add another dongle and set up a dummy channel towards 855.000 mhz. You need to get one dongle to stay around the lower 2 mhz of the site channels and the second dongle near the higher end of the site freqs. The dongles will give you about 2mhz up and 2mhz down from the center of that. Pretty sure you might also have to set the dongles to auto start.

1 (1)	003 (3)	Northeast Tarrant	Tarrant	851.0375	851.4875c	852.1125c	852.5375c	853.7875c	854.0125	854.9875
				855.2375	855.4875

 

[graphton]

Add another dongle and set up a dummy channel towards 855.000 mhz. You need to get one dongle to stay around the lower 2 mhz of the site channels and the second dongle near the higher end of the site freqs. The dongles will give you about 2mhz up and 2mhz down from the center of that. Pretty sure you might also have to set the dongles to auto start.

1 (1)	003 (3)	Northeast Tarrant	Tarrant	851.0375	851.4875c	852.1125c	852.5375c	853.7875c	854.0125	854.9875
				855.2375	855.4875

Thanks for the Assist! I will try that out, grabbing another dongle today.

 

[NATGIO]

Add another dongle and set up a dummy channel towards 855.000 mhz. You need to get one dongle to stay around the lower 2 mhz of the site channels and the second dongle near the higher end of the site freqs. The dongles will give you about 2mhz up and 2mhz down from the center of that. Pretty sure you might also have to set the dongles to auto start.

1 (1)	003 (3)	Northeast Tarrant	Tarrant	851.0375	851.4875c	852.1125c	852.5375c	853.7875c	854.0125	854.9875
				855.2375	855.4875

I actually have my second rtl-sdr V4 dongle coming in today precisely for this issue. But I have only been monitoring the Arlington, TX control frequency in the NTIRN network from Radio Reference. While I believe everything is functioning well for me, I do see "MAX TRAFFIC CHANNELS EXCEEDED" 99% of the events and "CHANNEL START REJECTED TUNER UNAVAILABLE" a lot as well. So I am assuming if I don't make a dummy channel but simply give sdrtrunk a second dongle that those error messages will go away, at least for rejected channel starts. Because that's probably voice communications I am missing out on, maybe ones that show in the events, but can't be played because they're too far away (2.4Mghz) from the control main control channel.

You can watch the livestream of my sdrtrunk running Arlington control on one (1) RTL-SDR V4 dongle on the NTIRN network. I am in North Arlington, well within range of Arlington control frequencies, right?

YouTube.securecpu.dev is my YouTube channel which should have a livestream on the front page. Oh, and I do have my dipole antenna at the correct combined length for 850Mhz, or as closely possible. And if you could explain to me the proper way to make a dummy channel, and if it messes anything up or just makes things work better, is a dummy channel even necessary?

1 (1)	008 (8)	Arlington	Tarrant	854.8125	855.1375	856.4875	856.7125	857.4875	857.7125	858.4875c
				858.7125c	859.4875c	859.7125c

 

[dave3825]

Since this post was made, now one can set the dongles area of operation (with latest version) which should eliminate the need for a dummy channels. The spread of those freqs is like 4.9 or 5 mhz so you may need to try running the dongles at 2.56 sample rate but I'm not sure of the actual usable on the V4.



If the dongle can see 2.56 mhz of spectrum, basically take the lowest freq, and set as minimum, and add 2.56 to that, enter that as maximum for 1st dongle.

Then the opposite on the second dongle taking the highest freq, setting as maximum, and minusing 2.56 from that, and entering that as minimum. May have a little overlap so you can adjust those numbers as needed/wanted.
If the 2 v4's can't cover the whole spread, then a 3rd dongle may be needed.

 

[maus92]

In the Nightly version at least, the program detects the Sample Rate of the SDR, then adds that amount to the Minimum value you entered to automatically calculate the Maximum value. The Arlington site *may* require a 3rd SDR.

 

[Enforcer52]

is a dummy channel even necessary

Short Answer=NO

My setup is 6 rtl-sdrs (1 dongle for VHF freqs) running SDRTrunk.

On my sdr setup I scan up to 6 systems, 4 with control channels in the 853-854mhz range so 1 dongle for them. 2 with control channels in the 773-774 range, so 1 dongle for them.

I then have 3 dongles that have NO dummy channel set, as that locks the dongle into a 2.4mhz range. My channels run from 769.21875 to 858.2125 for a total of 47 channels across the 6 systems. The software automatically determines which of the extra 3 dongles is available according to the frequency it needs. The dongles will jump between 700-800mhz as needed.

I have a 7th dongle that I did have on the system for awhile but it was never needed or used when observing the Tuners tab, only the 3 dongles have ever been needed even when the system was getting 10-12 channels at the same time. So moved the 7th dongle to another computer to use SDR++.

When I have brought the system up to Fort Worth and monitored the NTIRN Simulcast system both Fort Worth Simulcast layers 1 & 2, it has worked great picking up everything that is not encrypted. including North Richland Hills. It actually works better than my SDS200 that can only receive 1 channel at a time.

 

[dave3825]

Answer depends on ones site freqs, the number of dongles and the dongles usable bandwidth. Some people would not have needed it while others did need it. I did needed it a while back when running Nooelec's but do not any more.

 

[Harold]

Wrong site. They are on the Layer 2 site.