op25 with 2 dongles?

[da2ricky]

Can you run OP25 with two RTL-SDR dongles? If so, would there be any benefit in doing so?

My current config looks like this, how would I modify it to add the second dongle?

./rx.py --args 'rtl' -N 'LNA:35' -S 2048000 -f 853.7875e6 -o 25000 -q -2 -T trunk.tsv -V -2 -U -l http:192.168.60.226:8080 2> stderr.2

 

[nick0909]

OP25 only needs one dongle to track a system, it tunes to the new frequency on its own. As I understand it, enough of the control channel data is encoded in every frequency that it can pick up on talkgroups going active without being on the control channel all the time, so it doesn't need multiple dongles.

You can use multiple dongles to run multiple copies of OP25 and track multiple trunk systems at once from a single computer.

 

[boatbod]

./rx.py --args 'rtl' -N 'LNA:35' -S 2048000 -f 853.7875e6 -o 25000 -q -2 -T trunk.tsv -V -2 -U -l http:192.168.60.226:8080 2> stderr.2

You can safely eliminate the "-f ..." and "-o ..." options

 

[foxtail]

Should the -S number be that big? Just wondering?

 

[boatbod]

Should the -S number be that big? Just wondering?

The answer to that is entirely hardware dependent! With most of the cheapie RTL dongles you can run very happily with "-S 960000" but if you have more specialist hardware such as an Airspy you may find only a limited number of specific sample rates supported by the hardware.