I have been listening to a single digital voice channel of the Central New York Interoperable Communications Consortium (CNYICC) Network - using $20DVT tuner - USB stick and a PC running GNU software radio.
Originally Posted by rak313
I just got the software radio OP25 working on a $20 DTV USB stick ( The RTL2832U / Elonics E4000 SDR Radio - AKA "The $20 SDR" | Ham Radio Science
) - where the PC does the signal processing. The software application for OP25 is here DecoderPage
It assumes you have already installed the gnu-radio GNU Radio - WikiStart - gnuradio.org
On top of these 2 applications the OP25.grc code ( from here Gr-baz - SpenchWiki
) allows non-programmers to use the gnu graphical companion to change what processing blocks are in the receiver chain. I can now hear my local county's P25 audio (although only 1 channel at a time).
This took me a while - because an updated version of the GNU software radio broke the OP25 application. So patches were required. (not to mention that no one said it was broke in the 1st place- so I was left thinking I must be doing something wrong.) Eventually I stumbled across this link which explained how to fix it: OP25 - SpenchWiki
I live in the Westvale area - near Fairmount. The received audio transmissions are very good - with basically 0 breakups. There are occasions where the audio goes R2D2 like - but I believe these are encrypted transmissions.
I am only listening to 1 digital voice channel (its how the software is set up) - yet I seem to hear full back and forth conversations. I thought - being a P25 trunked system - that each time a user keyed on - a voice channel was selected. and when the user keyed-off, that channel was freed up. So every key-on could result in a different voice channel. So I expected to only hear one a total mixed up mess when listening. Instead - it seems like I am hearing complete conversations.