Using an SDR as a scanner

[PhillyPhoto]

I'm new to SDR and should have my first 2 donlges Wednesday. My main question is, can I scan through multiple trunked systems (or conventional frequencies) at one time, or does it have to be setup to scan only one system at once?

Basically what I want to do is have a software scanner, where it checks a control channel in a system for my selected talkgroups being active, if there are none it would go to the next system and check on that. Is that possible with UniTrunker today? Throwing conventional channels in a scan list would be a bonus but I'm not worried about it at this particular point.

 

[moonbounce]

I can tell you that I have had no luck getting the scanner pluggin to work. It scans very fast but I can't get it to stop on any frequency. I have tried many adjustments to no avail, best of luck, let us ( me ) know how you make out.

Moonbounce

 

[Boatanchor]

I can tell you that I have had no luck getting the scanner pluggin to work. It scans very fast but I can't get it to stop on any frequency. I have tried many adjustments to no avail, best of luck, let us ( me ) know how you make out.

Moonbounce

I had this problem too with SDRSHARP and the scanner plugin.
Never really got it working satisfactorily. I could get the scanner to stop (mostly) on busy channels eventually, but I had to slow the scan rate right down to a couple of channels a second and reduce the FFT resolution to the minimum setting. This told me that part of the problem is the way the plugin uses the FFT window to determine the RSSI/Signal level to stop the scan at.

Presumably, at higher FFT resolution the scanner plugin struggles to determine the actual RSSI/Signal level from the FFT window due to the large number of data points and the varying nature of FM signals.
If the Plugin takes the RSSI/Signal level from the exact center of the modulated carrier/channel, the scanner plugin would be hard pushed to obtain an actual RSSI/signal level in the short time that it is tuned to the channel as the carrier is deviating +- 2 or more Khz from the center frequency..

I kind of confirmed this by scanning an un-modulated signal and the scanner was able to stop on the frequency even with relatively fast scan rates. But add voice or P25 modulation and the scanner plugin really struggles.

Anyway, that just my best guess at this point in time..

It's a real shame because I had great expectations for the scanner.. Maybe in time an updated version will be released that addresses these issues.

 

[PhillyPhoto]

Well, it looks like I'm going to have to slow down a little bit, since the setup has been way more complicated than it seemed from online guides. The biggest issue I've faced is that SDR# is different from what I've been reading as far as selecting the input, as well as the plugins. I had been reading this guide as a preliminary background on getting it setup, but they use SDR# 335 whereas I'm using the auto-install version which is the dev version of 1100 something I believe.

I couldn't even get much of it to run at all on my Win8 laptop (DSD wouldn't even launch), so I gave up on that and got the dongle working in SDR# last night on a Win7 desktop. This morning I found a control channel and got UniTrunker to decode for about 3 minutes, and now it's not picking anything up after just dropping in the remote.dll file. I think I'm going to go a little crazy trying to figure this out, but it looks like it will be worth it in the end.

I still got my fingers crossed, and will have to do a lot more reading and tweaking!

 

[Danoman]

I used this info to get Unitrunker working with my 2 dongles.

SDRSharp UniTrunker Support


You can only monitor one system at a time, but if you had more dongles you can run as many receivers in Unitrunker as your system can handle.

I may pickup 2 more dongles myself as I have 2 active systems in my area.

 

[PhillyPhoto]

I was going off that, but I guess it's true what they say - read every instruction lol. After some head scratching and tweaking, I'm finally picking up a type II P25 system!