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op25 (police radio)

Posted: Fri Oct 19, 2018 9:43 pm
by studysession
Question about op25 -
Taken me couple of weeks to come this far. I believe I have the trunk.tsv & mycity.tsv file configured correctly. Anything I find online says I need to adjust the -q setting to get things working. I can never get the line over the peak of the frequency. Any help would be appreciated as I have tried many positive and negative numbers and not moved that line at all.

In the photos you you can see the syntax I have and what has been showing on my screen. I keep switching between the RTL-SDR & HackRF to see if there is anything different. Same result regardless which one I use.

THANK YOU :?:

Re: op25 (police radio)

Posted: Sat Oct 20, 2018 2:24 am
by phil
It's been a few months since i used my op25, but from memory, there are keys (poss. the arrow keys) that allow for live fine tuning. Have you tried those in conjunction with the phase plot?

Re: op25 (police radio)

Posted: Sun Jan 06, 2019 8:55 pm
by ScanCaster
studysession wrote:
Fri Oct 19, 2018 9:43 pm
Question about op25 -
Taken me couple of weeks to come this far. I believe I have the trunk.tsv & mycity.tsv file configured correctly. Anything I find online says I need to adjust the -q setting to get things working. I can never get the line over the peak of the frequency. Any help would be appreciated as I have tried many positive and negative numbers and not moved that line at all.

In the photos you you can see the syntax I have and what has been showing on my screen. I keep switching between the RTL-SDR & HackRF to see if there is anything different. Same result regardless which one I use.

THANK YOU :?:
You are correct, the -q function is the PPM correction more commonly used as -p for most other RTL software... but thats OP25... they like to go against the grain.

The issue is YOUR COMMAND...

YOU have:

Code: Select all

./rx.py --args 'hackrf' --gains 'lna:49' -f 851.1625e6 -T newtrunk.tsv -S 1000000 -o 25000 -w 2>stderr.2 -q -2 

The issue is the -q 2 command is AFTER where it needs to be your passing it to the pipe of stderr, rx.py never get its so it never moves.

CHANGE TO;

Code: Select all

./rx.py --args 'hackrf' --gains 'lna:49' -f 851.1625e6  -q -2 -T newtrunk.tsv -S 1000000 -o 25000 -w 2>stderr.2 
You may have to play with it... I was under the understanding the hackrf's were far more stable and closer to spec v. the asian generic dongles... especially for something thats $200!