OP25 Major New OP25 Release - Seeking Beta Testers

KA1RBI

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Does it work with discriminator audio or only SDRs?

rx.py works with the disctap - to run in that mode use a command such as
Code:
rx.py -a -g 65

The "-a" signifies direct audio input and the "-g" option (required in this case) specifies the audio level gain. Typically the audio level coming in is highly variable and needs to be adjusted. The "datascope" plot is useful for this - make sure the four nodal points in the eye pattern align with the -3/-1/+1/+3 points on the vertical axis.
 

KA1RBI

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Practically all of the development work in recent years (the past 8-m years anyway) has been focussing on SDRs, primarily the RTL-SDR. I'd say that using a discriminator tap would prove to be somewhat limiting/disappointing, espcially for trunk tracking/LSM/CQPSK/Phase 2 usage.

There is a niche though where the disc tap comes into its own. I have somewhere around 15-20 stations here that can only be received with a tapped scanner. The RTL does not have the dynamic range to pull in a lot of the weak stuff (such as Canadian skip during tropo season).

If the scanner has a strong receiver like an old RS PRO-2006, as I use here, the performance can approach that of a "real system radio".

for trunk tracking/LSM/CQPSK/Phase 2 usage

Yes - things like simulcast, Phase 2, CQPSK (etc). are very iffy, to say the least, when using the disctap. Simulcast system users of many generations of scanners (exc. SDS) have learned this lesson the hard way.

And even here there is a way to get the strong performance of the '2006 combined with the power of SDR. My PRO 2006 is also tapped just prior to the FM demod stage (specifically tapped at the 455 KHz IF). Using this combo I use the 2006 (also equipped with an Optocom OS-456) to receive P25 simulcast systems. In this mode the rx (actually mullti_rx) is tuned to a fixed frequency of 24 KHz (the nominal 4th IF resulting from downconverting the 455 KHz into something compatible with PC sound cards). Again, the point is simply that "real system radio" performance is available to the hobbyist who wants to put in the effort.
 

nd5y

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Does this new version use different commands than the version from a few weeks ago?
I think I tried ./rx.py and it gave errors like it couldn't find some configuration files or something.
 

KA1RBI

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I'll have to relook at it. Last time I tried, there were some issues with dependencies that I couldn't solve.

If you do it would be good of you to post specific error reports. We cannot fix everything on every potential platform without these reports.

Since the announcement of the alpha test availability (last week) I've pushed almost a dozen commits for bug reports that were submitted to us. Keep these coming please!

Max
 

KA1RBI

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Does this new version use different commands than the version from a few weeks ago?
I think I tried ./rx.py and it gave errors like it couldn't find some configuration files or something.

Could you post the **specific** errors please? As far as I know rx.py should work as before.
 

nd5y

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There is a niche though where the disc tap comes into its own. I have somewhere around 15-20 stations here that can only be received with a tapped scanner. The RTL does not have the dynamic range to pull in a lot of the weak stuff (such as Canadian skip during tropo season).

If the scanner has a strong receiver like an old RS PRO-2006, as I use here, the performance can approach that of a "real system radio".
Thats my problem. Dongles are useless here because they don't have the sensitivity or dynamic range. My Pro-2006 was great with Unitrunker and DSD but now it's on it's deathbed.
 

nd5y

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Could you post the **specific** errors please? As far as I know rx.py should work as before.
I don't rememer what errors it was making. I would have to make another live USB and compile and install it again sometime.
Have you heard of anybody running it successfully on a MX Linux 19.4 persistent live USB?
Is there a .deb package, flatpak or AppImage available?

Basically all I want is decoding control channels. Not trunk tracking.
Do you need to set up config files for each system you want to monitor ahead of time or can you just run it and start decoding cc data like Unitrunker?
 

Girard747

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Thats my problem. Dongles are useless here because they don't have the sensitivity or dynamic range. My Pro-2006 was great with Unitrunker and DSD but now it's on it's deathbed.
Have you tried hooking up a LNA before the SDR? Really makes a world of difference.
 

Outerdog

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Wonder if just update and upgrade would install this. But I'll test it out. Or I just install the new update.
Thanks

apt update and apt upgrade will deal with whatever is maintained by the package manager. While several of OP25 dependencies are maintained by the package manager, the OP25 core itself is not. Therefore, you should pull down the update manually.
 

awasser1

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wouldnt git pull work? then do install again. I dont think this version had rebuild.sh but if it does use that.
 

KA1RBI

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The very, very first sentence of the "Installation" section in the README-July-2021 file:
First locate and change to your current OP25 install build/ directory and
run the command
Code:
     sude make uninstall

Please read the instructions :)
Max
 

jslezak

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I'm absolutely loving the update. Amazing work!

Not sure if it's a bug or me, but I can't get the '-p' key to function for pulling up the plots. I get a blank square where I suppose they'd show up. Tried several browsers and disabling any ad blockers. Also tried natively on that device and again from a different device's browser. It does recognize the command as the P option shows up in the box near the top right saying "FDMA".20210804_143148.jpg

I am using it on a Pi4 with a touchscreen and it's epic!

Thanks again,
Joe
 

KA1RBI

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The plots are displayed under the "Home" tab, and it depends on whether you're running rx.py or multi_rx.py as to how to get the plots.

For rx.py use a command option such as "-P symbol,constellation" .

For multi_rx.py add a definition (json key/value) in the "channel" entry for the desired channel (cc or vc, etc), such as "plot": "symbol,constellation" .

Max
 

Outerdog

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The "P" key can be pressed on the RX tab to show the plots on that tab. As Max points out, if the plots are not showing up on the Home tab, then something is wrong with the config / command options.
 
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I gave it a quick test run last night in VM ware couldn't get the logs to work. When I get home I'll gave it a go again
 

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blantonl

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Amazing piece of software and outstanding work.

I've deployed this version to a Raspberry Pi 4 in New Orleans monitoring the LWIN system.

One thing I've noticed is when clicking "Go to" and entering a talkgroup, when you are already holding on a talkgroup, OP25 simply resets to scanning, requiring you to "Go to" and enter a talkgroup again to actually switch between holding on different talkgroups just using the Go To button.

Also, using Safari on Mac OS X, running overnight, the web interface was reloaded multiple times for using too much memory, so there's a memory leak somewhere in the interface on Safari.

Command I'm using on the Rpi4

Code:
./rx.py --args "airspy" -N 'IF:10,MIX:10,LNA:10' -f 774.78125e6 -S 6000000  -q 1 -l 'http:0.0.0.0:8080' -T trunk.tsv -w -W 10.1.1.102 -V

Command I'm using for VLC on my local Mac OS X workstation

Code:
alias vlc='/Applications/VLC.app/Contents/MacOS/VLC'
vlc --clock-jitter=500 --network-caching=0 --demux=rawaud --rawaud-channels 1 --rawaud-samplerate 8000 udp://@:23456

Screen Shot 2021-08-08 at 8.19.43 AM.png
 
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