Decoding P25 Phase 2 help.

[F35GUY]

Hi all!

Finally received both my sdr dongles on order and went to set them up yesterday. I did so much research before embarking on this journey but I ran into my first problem when trying to set up sdr trunk.

I'm looking to scan Toronto Emergency services, which I intend to tune into the west simulcast site. On RR it shows Toronto as operating on a P25 Phase 2 system, and I am confused as there is no information if it is TDMA or FDMA. Sdr trunk requires this when going to set up a channel for decoding (as far as I know), and I'm looking for some help on this topic specifically.

In addition, I watched multiple YouTube videos on setting up a P25 decoder in SDR trunk, but I couldn't find a single one on P25 Phase 2 (all videos were Phase 1). The Toronto west simulcast has 4 control channels, and when I was playing around with the software yesterday it was only giving me the option to add 1.

I'm a beginner here so any help would be gladly appreciated.

Note: Im running two RTL-SDR v4 dongles

 

[MTL_Emergencies]

P25 Phase II is TDMA. TFS comms are TDMA while the Control Channel is P25 Phase I (FDMA). Setup the system as P25 phase I since your CC is Phase I and SDR trunk should automatically decode P25 Phase II voice channels.

 

[Enjoi19]

The control channel is Phase 1, FDMA. To add more control channels hit "add".

The talkgroups are a mix of P1/2.

 

[F35GUY]

Extremely helpful! Thanks a lot.

 

[Enjoi19]

No problem. Note that 2 dongles will work to cover all 4 Toronto transmit sites, but you may not receive all of them from one spot. North and East can be tricky from the west end, depending on location. South carries the most traffic though and most major calls run through it.

 

[F35GUY]

Last question I promise. I set up the channel for the west site and for my first alias setup the dispatch talk group. When I go to press play it shows the channel as idle. How can I fix this? I see you mentioned most calls going through the south site. Should I setup a channel for it too? My antenna is at the right length and is securely connected to the sdrs which sdr trunk recognizes. Although when I first went to start the channel it said no tuner available. And in order for it to start I had to go to user preferences in the tuner section and switch it to hethero.

 

[Enjoi19]

If you're not seeing the channel locked and it's idle, you may not be getting reception or a good decode - you will need to adjust the tuners gain according to try and get a good signal

 

[dave3825]

You can also increase the time it looks for the cc by increasing the Freq Rotation Delay. I keep mine to a minimum of 1000.