Software Defined Radio On Minnesota ARMER

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JASII

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I know that there is a specific SDR Forum, but I posted this here to see who is using SDR in Minnesota and how well it performs decoding the Minnesota ARMER system. What SDR(s) are you using?

I just happened to see that there is a sale price on the Air Spy Mini for $80.00, which would seem to make it a reasonable enough price to use to just search around the bands with.
rtl-sdr.com - RTL-SDR (RTL2832U) and software defined radio news and projects. Also featuring Airspy, HackRF, FCD, SDRplay and more.

I also see that HRO has several different SDR Play versions available for under $200.00.
Distributors – SDRplay

While the ARMER system certainly isn't the only thing that I plan to monitor with this, if one, or some, decode LSM/CQPSK better than others, I would be more inclined to get one that decodes it properly.

Also, things like decoding multiple digital formats is a plus for me. So, if it decodes MOTO TRBO/DMR. If it decodes MOTO TRBO/DMR, Icom D-Star, and Yaesu System Fusion, all the better.
 

stmills

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I am using a system made up of 2 low cost rtl-SDR dongles plugged into a powered USB hub, then into A Winbook tablet running windows 10. I track ARMER with Unitrunker and decode the audio using DSD +.
Unitrunker allows for multiple receivers to run off each Dongle. I monitor 2-001, 2-002, 1-001& 1-009- the spread of frequencies involved requires multiple dongles to operate well.
Some of the name brand receivers have better frequencies spread than the low cost RTL-SDR receivers have.
 

JASII

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Thank you very much for the reply, Steve. How does the audio sound on that? Is it muddy like most scanners on simulcast sites or does it decode it properly?
 

stmills

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Thank you very much for the reply, Steve. How does the audio sound on that? Is it muddy like most scanners on simulcast sites or does it decode it properly?


I have good audio on mine because I run it through a good quality amplified speaker so it is much better than my 396- more comparable to a commercial radio than a scanner.
I look at it as comparing the audio on a pocket fm radio vs a component stereo- the first I buy for small portability and only ok sound- the other I select the parts I like the best - you buy a USB receiver- plug it into the computer of your choice, select the software that processes the way you want, then select a sound card and speaker system - you will have better sound than the speaker in most scanners from the start.
 

wogggieee

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Hugo , MN
I have two RLT dongles running Unitunker, but no audio. I haven't had much success getting them to work on audio in this area. I think the simulcast stuff is too much for them. When I've used them in Hibbing and in Michigan they're worked pretty well for audio. Occasional digitization but overall decent. I'd think a better quality SDR unit would work better as John Moe's setup demonstrated. There is a new one thats coming/came out that John had mentioned to me at previous meetings called Lime SDR. So that might be something to check out too.
 

JASII

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Thank you very much for the replies. As much as I really enjoy my Unication G5 for monitoring ARMER, I do somewhat miss having a Uniden Bearcat BCD996XT in TRUNK SEARCH mode. I just found it interesting to hear what unexpected talkgroups would pop up from time to time. I didn't monitor everything, of course. I locked out most of the stuff that was expected on my local site and neighboring sites. By listening that way, it was easy to catch unexpected users as they traveled through.

If Uniden or Whistler can ever come up with a way to properly decode CQPSK signals, it would make an enormous improvement on simulcast sites. Or, if Unication ever adds the ability to lock out talkgroups while in Monitor Mode, that would be quite helpful.
 

B-One

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At times I am running five dongles at a time monitoring up to 9 sites. ARMER is run through Unitrunker and digital is decoded by DSD+. One dongle monitors Voice that has the TGs and UIDs prioritized. The other four dongles monitor the control channels for the sites I wish to monitor.

I have a homebrew coax colinear antenna mounted on my roof that leads to a simple 4 output TV splitter/amplifier that feeds the dongles. One of the antenna outputs is connected to a pigtail splitter to get me to 5 outputs from the splitter/amplifier. I have optimized the DSD+ settings using dsdtune.exe. I use DSD+ to record the output in case I wish to review the audio.

I am in a rural location in NW MN and none of the sites I monitor use simulcast. Audio is fantastic 95% of the time, but can occasionally be a bit digitized depending on the correction factor (this gets better as the dongles warm and settle), how many sites I monitor (more is worse), and how many programs are running in the background.

I use a mix of the cheap blue dongles and the nano dongles. I have been having difficulty with the blue dongles shutting down and becoming inoperable lately. I need to shut down Unitrunker, unplug the usb hub, replug the usb hub and restart Unitrunker to solve the problem. I have posted on this in the SDR section, but haven't seen any replys yet.
 

blue5011

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Faribault County, MN
I am using a system made up of 2 low cost rtl-SDR dongles plugged into a powered USB hub, then into A Winbook tablet running windows 10. I track ARMER with Unitrunker and decode the audio using DSD +.
How do you get that all "on-line"?

1) I am thinking plug-in the dongles.

2) bring up Unitrunker, recognize the dongles?

3) And then bring up DSD+?

Bought two cheap USB-SDR dongles. I can get one to receive the local FM radio station and the local VHF Ham repeater.

I can see the 850mhz signals received in SDRSharp waterfall (control channel and one w/ in bandwidth voice channel). But all audio I hear is static (in 850mhz ARMER digital band).
 

stmills

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Dongles feed to Unitrunker, audio then runs through Virtual Patch Cable App to DSD that processes audio then Out to audio on the computer
 

blue5011

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Dongles feed to Unitrunker, audio then runs through Virtual Patch Cable App to DSD that processes audio then Out to audio on the computer
Ok...

Where do I find a "virtual patch cable app"?

I am fairly competent w/ computers (first computer in the DOS era), but have never used "one" program to send to "another" program.

Maybe just recommend some links to the info I need by way of PM.

Thanks
 

blue5011

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Thanks.

Someday I will need to go see someone who has this SDR dongle decoding in action. It just looks way to complicated for me right now.

Only one other person around me is interested in the SDR dongle experimentation, and I am using W10 and the other guy is using a W_7 computer. So it is hard to even compare what we see on our screens as the computers "see" things abit different.
 

omgitstony

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I use a dongle and watch the data of the Hennepin E/W sites with Unitrunker. When I try ARMER audio with DSD+ it sounds pretty digitized, I am guessing its the simulcasting that is playing games on my end. When I use the same setup/settings and monitor the City of Eden Prairie P25, the audio is perfect. I get the same results if I either use Unitrunker to follow the audio and output it to DSD+ as I do with just following the freqs as they show up on SDR# and output to DSD+ (ARMER audio digitized, EP audio perfect).

All is good because I have other scanners that i can pull audio from so that I am not sitting here in silence. :)
 

B-One

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Thanks.

Someday I will need to go see someone who has this SDR dongle decoding in action. It just looks way to complicated for me right now.

Only one other person around me is interested in the SDR dongle experimentation, and I am using W10 and the other guy is using a W_7 computer. So it is hard to even compare what we see on our screens as the computers "see" things abit different.
Cost of getting into SDR is low... monetarily speaking.

Time is the big cost. You can get everything working with plenty of tweaking, internet research and questions in the appropriate forums here. If you are lucky you can get up and running with 1-2 hours of time. I would not be one to promise that you would be lucky.
 

B-One

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I use a dongle and watch the data of the Hennepin E/W sites with Unitrunker. When I try ARMER audio with DSD+ it sounds pretty digitized, I am guessing its the simulcasting that is playing games on my end. When I use the same setup/settings and monitor the City of Eden Prairie P25, the audio is perfect. I get the same results if I either use Unitrunker to follow the audio and output it to DSD+ as I do with just following the freqs as they show up on SDR# and output to DSD+ (ARMER audio digitized, EP audio perfect).

All is good because I have other scanners that i can pull audio from so that I am not sitting here in silence. :)
I have had some luck getting rid of the digitization with DSD Tune, but I am rural. Here is a link to some info: DSDTune - The RadioReference Wiki
 

blue5011

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Well I fumbled around enough on Unitrunker to get it to work w/ one of my SDR dongles.

It is interesting to see the window that shows the site/ freqs/ radio ID's cycle through.

I wish there was a way to save this "log" of hits that I see on the screen.

I looked at additional Unitrunker info pages and have yet to come up w/ a way to save the "log hits" to a file.

Once I feel comfortable getting this software working, I will go to the "virtual cable" thingy.

Thanks All for the help!
 

B-One

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Well I fumbled around enough on Unitrunker to get it to work w/ one of my SDR dongles.

It is interesting to see the window that shows the site/ freqs/ radio ID's cycle through.

I wish there was a way to save this "log" of hits that I see on the screen.

I looked at additional Unitrunker info pages and have yet to come up w/ a way to save the "log hits" to a file.

Once I feel comfortable getting this software working, I will go to the "virtual cable" thingy.

Thanks All for the help!
Choose the site(s) you wish to log
On the bottom of that (those) site windows click the info tab.
On the screen that you see, click the box to the right of the "Log" choice.
 

blue5011

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Choose the site(s) you wish to log
On the bottom of that (those) site windows click the info tab.
On the screen that you see, click the box to the right of the "Log" choice.
I got it so I can see the "log".

The issue now is saving it and finding it in a better/ different location. (I am used to being able to **save** files in a specific directory where I can easily find them again)

I did find the "log files" but they are not in a very user friendly format.

I expected to be able to copy/ see them in a spreadsheet format, instead it is in some kind of "html" format.
 

B-One

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I got it so I can see the "log".

The issue now is saving it and finding it in a better/ different location. (I am used to being able to **save** files in a specific directory where I can easily find them again)

I did find the "log files" but they are not in a very user friendly format.

I expected to be able to copy/ see them in a spreadsheet format, instead it is in some kind of "html" format.
I can't be much help from here. I don't use the logs myself. I just know that they exist. I think you can open the files in excel and manipulate them.
 

Imago

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I'm using the NooElec - NooElec NESDR SMArt - Premium RTL-SDR w/ Aluminum Enclosure, 0.5PPM TCXO, SMA Input & 3 Antennas. RTL2832U & R820T2-Based. - SDR Receivers - Software Defined Radio dongle and get 2.88Mhz bandwidth which is just enough to cover the entire site I listen to.

Check out the SDRTrunk software written in cross-platform Java; I've recently setup a
Windows installer build slave for helping test/fix betas: https://github.com/ImagoTrigger/sdrtrunk/releases

As for performance, the stock antenna on this model NooElec - NooElec NESDR Mini SDR & DVB-T USB Stick (RTL2832 + R820T) w/ Antenna and Remote Control - SDR Receivers - Software Defined Radio works best so far but that stick only gets 2.4Mhz and I need to use a usb extension cord to move it away from the PC to get a good quality TSBK/s rate (25+). The aluminum enclosed ones I linked first do not have this issue.

Lastly, voice decoding quality with the JMBE seems much better than the previously mentioned software.

$27.95
 
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