Hi Guys,
Just thought I would share a small project I have been tinkering with for a while now. It is an experimental, open source P25 SDR based transceiver. For the software stack, I am using linux, with GNURadio and the free and open OP25 project. The hardware is an Ettus Research USRP as an exciter, which puts out a maximum of 100mw, running about 70 milliwatts on the 70cm band. This feeds into a MiniKits 70cm 60 watt amplifier than produces rated power with only 50mw input.
I think it's kinda neat as not many people are playing with homebrew SDR transmitters. I could ramble on all day about it, as I really love this project, but as they say a picture tells a thousand words, so here's some videos.
Testing with voice transmissions:-
[youtube]https://www.youtube.com/watch?v=Ba0E4hMYqag[/youtube]
https://www.youtube.com/watch?v=Ba0E4hMYqag
Later experiments generating TIA-102 standard P25 test patterns:-
[youtube]https://www.youtube.com/watch?v=baWF5qQ6L_g&[/youtube]
https://www.youtube.com/watch?v=baWF5qQ6L_g&
Cheers,
Matt
Homebrew P25 SDR Transmitter
Homebrew P25 SDR Transmitter
Matt, VK2LK