Homebrew P25 SDR Transmitter

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VK2LK
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Joined: Sun Jan 15, 2012 11:00 pm
Location: Sydney, Australia

Homebrew P25 SDR Transmitter

Post by VK2LK » Tue Oct 23, 2018 4:44 pm

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
Matt, VK2LK

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