Unitrunker Decoding with R820T

[aps_ak]

I recently purchased an R820T stick, and would like to use it with Unitrunker to decode some control channels (not interested in listening to audio yet).

I set everything up in SDRSharp, got drivers installed and am hearing control channels/FM Broadcast, as well as some conventional analog channels.

I set the R820T on unitrunker as well, am able to get it to run, and I can hear the control channel and see activity on the oscilloscope. I cant get a site window to come up, however, probably because I for some reason can't get a good decode rate. The health jumps up to about 17, and then gradually goes down to zero. I know I should have better reception of the cc than that. I've been using my scanner to decode with Unitrunker for years.

Some articles talk about calibrating the stick. I am a bit confused on how this is done, as I am totally new to the SDR scene. How can I tweak my settings further to make this work?

This is all run on Windows 7. Thanks.

 

[reconrider8]

first off what version of unitrunker are you runing? the newer versions dont even need sdr to run just the data in. second you have to go to the config button in sdr and youll see a box thingy marked as ppm this is your calibration number mine runs anywhere from 48-52 but it will vary on computer dongle and the temp around you. youll need to listen to the cc and keep going until it sounds clear maybe skip by 5's until you get close then go up and down a few. it has to be spot on for it to really decode at a good % rate but once you get close it will sound clear but you may still have to walk it a little. then you have to walk around a bit until the dongle gets warm but after that it may be a little tweaking from there on out but for the most part if its staying inside it shouldnt change more then 1 ppm or so.

 

[aps_ak]

My unitrunker version is 1.0.28.4.

So, youre saying to calibrate it - play with the ppm settings, let the dongle warm up and then keep adjusting it till it gets totally clear?

What is the best sampling rate, and how do I determine that?

 

[aps_ak]

Well, played around with frequency correction - and I at least got a site window to pop up! So ill keep tweaking it to adjust the health.

 

[SCPD]

Follow these instructions to calibrate your RTL stick under the heading "Installation" :

UniTrunker | Realtek

"Adjust the correction factor until the "gutter" in the waterfall display lines up with the tune marker (a thin vertical red line in SDR#)."

Control channels make good reference signals for calibration.

Also, update to release 29.

 

[aps_ak]

Follow these instructions to calibrate your RTL stick under the heading "Installation" :

UniTrunker | Realtek

"Adjust the correction factor until the "gutter" in the waterfall display lines up with the tune marker (a thin vertical red line in SDR#)."

Control channels make good reference signals for calibration.

Also, update to release 29.

Will do. Although Im perfectly decoding a control channel at this moment.

Silly question - where is the 'gutter" on the waterfall display? The center?

 

[SCPD]

When there's a signal present, it appears as a trough or "gutter" aligned vertically across the waterfall. It's lateral position depends upon it's frequency relative to the center.

Example: you know there's a control channel at 935.5 Mhz. With 0 correction, you tune your RTL stick to that frequency. A red vertical line marks where you're tuned. A streak appears to the right. Believing that to the the real signal, you increase correction factor by increments of 10 until it overshoots the gutter. Then you decrease it by 1's until the red line is perfectly aligned over the actual signal.

You can use that number each time you configure other software to use the RTL stick.

If you have a second RTL stick, you'll have to repeat the process since the correction needed for each device varies.

 

[aps_ak]

Got it. Thank you.

 

[johnoconnor98]

I don't know if this is a thread jack or just a stupid question.
I just got a new WIN7 machine to replace my XP machine at work.
I downloaded the new UniTrunker and was excited to see you no longer need SDR# to tune the R820t.
I easily got Unitrunker to track a Motorola site near me.

My question is, how do I store all the different systems and/or control channels. The only way I see now is to manually stop the receiver, enter the control channel of the system I want to watch and restart the receiver.

Can I want to save each system/site so it's just a click away? Or do I have to manually edit the receiver freq each time?

 

[BM82557]

I don't know if this is a thread jack or just a stupid question.
I just got a new WIN7 machine to replace my XP machine at work.
I downloaded the new UniTrunker and was excited to see you no longer need SDR# to tune the R820t.
I easily got Unitrunker to track a Motorola site near me.

My question is, how do I store all the different systems and/or control channels. The only way I see now is to manually stop the receiver, enter the control channel of the system I want to watch and restart the receiver.

Can I want to save each system/site so it's just a click away? Or do I have to manually edit the receiver freq each time?

I setup separate signal receivers for the different systems I monitor.

 

[SCPD]

My question is, how do I store all the different systems and/or control channels. The only way I see now is to manually stop the receiver, enter the control channel of the system I want to watch and restart the receiver.

Correct.

I want to save each system/site so it's just a click away?

In the *next* public release you'll be able to pick a previously logged site. If the signal decoding receiver supports computer control, the program will tune it to a control channel - and off you go.

A "both" model, most inline models, and the R820T based RTL sticks will work.

I hope to make a release - with updated documentation - available soon.

 

[garys]

I'm setting up a second lap top for use with a R820T dongle. It's an ASUS with Windows 8.1 installed.

So far SDR#, DSD+, VBCable (two iterations, have all gone in without a hitch. Unitrunker is giving me a small hiccup, though. Actually two.

First, as with my Win7 laptop, I have to run it as an administrator or I get an error message. I can live with that.

The second problem is that I can't get audio to Unitrunker. I have the Receiver set "TYPE" Signal, "Mode;" R820D, "Role" Signal.

Under "Signal" I have RTL Device RTL2838UHIDIR000001, but no other settings available. That's different than my Win7 setting that has Audio Input, Sample Rate, Sample Size, Channel Settings.

Obviously, I did something wrong, but I can't figure out what. Is there a plug in for SDR# that I'm missing or is it something else?

Thanks.

 

[SCPD]

The ability to change a receiver's type is going away.

Delete the existing mis-configured receiver and create a new one.

Click the "+" button on the toolbar of the receivers tab.

Select "RTL2832U" to add a new receiver.

Select the actual device from the drop-down combo box.

A "Signal" receiver is a bare discriminator tap tied to an audio input so, clearly, not the right type for an RTL stick.

As long as the RTL stick has an R820T tuner chip, you don't need another SDR program.

 

[garys]

Thanks. I got it working, but not quite the way you described.

I set it up as a Signal Receiver via descriminator tap. Actually, I got it to work as a R820T as well, but need to read up on how to tune it to the frequency I want. I'll visit the site and dig through the documentation.

Also, for some reason one of my R820T dongles wouldn't work. I'll have to play around with that too, but it has no bearing on Unitrunker.

The ability to change a receiver's type is going away.

Delete the existing mis-configured receiver and create a new one.

Click the "+" button on the toolbar of the receivers tab.

Select "RTL2832U" to add a new receiver.

Select the actual device from the drop-down combo box.

A "Signal" receiver is a bare discriminator tap tied to an audio input so, clearly, not the right type for an RTL stick.

As long as the RTL stick has an R820T tuner chip, you don't need another SDR program.

 

[dmonty83]

Trying to setup as well...

I have an R820T and I'm going through the process of setting up UniTrunker (Ver. 1.0.30.10)

I'm using the steps described at RTL-SDR Tutorial: Following Trunked Radio with Unitrunker - rtl-sdr.com

When I get to the RTL Device drop down it is empty. I'm running Win7.

Any thoughts?

 

[mescalero]

I have an R820T and I'm going through the process of setting up UniTrunker (Ver. 1.0.30.10)

I'm using the steps described at RTL-SDR Tutorial: Following Trunked Radio with Unitrunker - rtl-sdr.com

When I get to the RTL Device drop down it is empty. I'm running Win7.

Any thoughts?

likely need reinistallarei driver with zadig as sysadmin
from the program window select list all devices and click interfae 0 (zero) and then reistall driver.
after you exit and try again if zadig now recognizes the dongle- launches unitrunker
other software as sdr not need
greetings