DSDPlus Can DSDPlus scan UHF and P25 channels ? If so any examples

[jerry01]

Can DSDPlus scan UHF and P25 channels , I just purchased one of these PiPo X9S TV Box 8.9 Inch Mini PC 4GB 64GB Intel Cherry Trail Z8350 Win10 OS . I plan on building a mobile unit with that mounted in a console. I am looking to scan Orange County NY Fire and Ems

 

[nosig55]

Using FMP24 and a scan list. That looks like a neat unit. I've wanted to make a mobile unit like you stated. Keep us posted how it works out.

 

[Forts]

I've looked at these units too for the same purpose. Curious to hear how you make out with it....

 

[RaleighGuy]

@jerry01 Here is the format (for the file @nosig55 mentioned)

 

[jerry01]

I am wondering if it would be better to run 2 rtl_sdr's one for p25 and one for UHF , thoughts.. BTW thanks for the file

 

[Reconrider]

I am wondering if it would be better to run 2 rtl_sdr's one for p25 and one for UHF , thoughts.. BTW thanks for the file

Any trunk system it's better. I know on p25 trunk it's way slower to run 1 sdr.
Having 2 will hold 1 sdr on the CC and the other to follow voice from the CC

 

[R0am3r]

I am wondering if it would be better to run 2 rtl_sdr's one for p25 and one for UHF , thoughts.. BTW thanks for the file

First of all, we need to clear up the terminology. P25 is a mode and UHF is a portion of the spectrum. UHF includes the spectrum from 300 MHz to 3 GHz.

To answer your question, two SDRs are more efficient than one. But, one will still work. I use one RTL-SDR to monitor a local P25 system using a Raspberry Pi. It works great!

 

[slicerwizard]

Any trunk system it's better. I know on p25 trunk it's way slower to run 1 sdr.
Having 2 will hold 1 sdr on the CC and the other to follow voice from the CC

So having one SDR switch from CC to VC is slower than having a second SDR switch from whatever frequency it's on to a VC? I ain't buying that one.

 

[Reconrider]

So having one SDR switch from CC to VC is slower than having a second SDR switch from whatever frequency it's on to a VC? I ain't buying that one.

Correct.
If you have 1 SDR it has to visit the CC after every voice ends to figure out who has the voice next.
If you have 2 SDRs, 1 sits on the CC and the other will follow without having any interruptions.

 

[slicerwizard]

If you have 1 SDR it has to visit the CC after every voice ends to figure out who has the voice next.

When monitoring P25 systems, it doesn't have to use the control channel to find another active call. And hopping back to the control channel and acquiring the CC datastream takes next to no time - what, maybe 100 ms max?

 

[Forts]

.....not to mention that's what a system radio does too. Goes to it's voice channel... when it's done goes back to the CC for further instructions.

Anywhoo... I'm monitoring 3 large trunking systems using 1 SDR each. Works just fine.

 

[CqDx]

Hi all,

I was able to set up FMP to scan the FMP24.scanlist frequencies but it doesn't seem to record. Can anyone confirm if there is no recording feature when using FMP in scanning mode?

 

[slicerwizard]

Should be able to record stuff if FMP24 is feeding DSD+. What kind of signals are you scanning?

 

[CqDx]

Just two conventional FM railroad channels, nothing fancy.

 

[slicerwizard]

If you start source audio recording in DSD+, you'll get a single wav file of just the active transmissions. This assumes you're using TCP linking or the newer direct linking between FMP24 and DSD+ FL.

 

[CqDx]

I see, would I be able to use per-call recording feature instead of one long single wav file? The readme file isn't too clear on that..

 

[slicerwizard]

The per-call stuff relies on link control data that's embedded in digital voice calls. I can't see how it would work with analog voice.

 

[a417]

As you are doing ...

Just two conventional FM railroad channels, nothing fancy.

You can use rtl_fm and ffmpeg to record FM conventional transmissions and store them without using DSD+.

 

[CqDx]

Appreciate it guys!