Running multiple instances of OP25

AB5ID

Member
Joined
Aug 6, 2007
Messages
233
Location
Lee's Summit, MO (Kansas City)
I'm considering adding a second dongle to my computer running OP25 and I'm having trouble finding the instructions to do this.
Is running 2 instances of OP25 and having both outputs feed the same headphone jack very difficult?
 

boatbod

Member
Joined
Mar 3, 2007
Messages
2,404
Location
Talbot Co, MD
I'm considering adding a second dongle to my computer running OP25 and I'm having trouble finding the instructions to do this.
Is running 2 instances of OP25 and having both outputs feed the same headphone jack very difficult?
With recent updates there's actually little need to run two instances because you can configure additional devices and output streams into one single application instance of multi_rx.py. There are various sample configurations included with the repo files. Assuming you are interested in P25 take a look at ~/op25/op25/gr-op25_repeater/apps/p25_example.json.

I'd be happy to guide you through the setup if you'd like. Please describe more about what you'd like to do, including link(s) to RRDB entry either in this thread or via PM.
 

AB5ID

Member
Joined
Aug 6, 2007
Messages
233
Location
Lee's Summit, MO (Kansas City)
With recent updates there's actually little need to run two instances because you can configure additional devices and output streams into one single application instance of multi_rx.py. There are various sample configurations included with the repo files. Assuming you are interested in P25 take a look at ~/op25/op25/gr-op25_repeater/apps/p25_example.json.

I'd be happy to guide you through the setup if you'd like. Please describe more about what you'd like to do, including link(s) to RRDB entry either in this thread or via PM.
Right now I'm monitoring these two sites:


With one dongle and a laptop running an older version of Skywave Linux (Ubuntu 16.04 LTS kernel 4.16.8-xanmod9)
My SDR dongle is a Nooelec NESDR SMArt v4.
A new P25 Phase 2 system became live a few months ago and a want to dedicate a new SDR just for it. Is there any benefit with having my second SDR dongle match the Nooelec NESDR SMArt v4 (I'm thinking about trying a RTL-SDR Blog V3 just to try something different)?

The second dongle would be for this site (which has very little traffic right now but traffic I want to hear as a priority):

I'll check out p25_example.json.
Thanks for any info!
 

boatbod

Member
Joined
Mar 3, 2007
Messages
2,404
Location
Talbot Co, MD
Physical sdr hardware can be the same or different... it really makes no difference to op25.

The first two RRDB entries list multiple CC freqs. Which one are you using?
For the second site (Lee Summit) I assume you want to treat it as a separate trunking system rather than it simply sharing TGIDs on the first system?
 

AB5ID

Member
Joined
Aug 6, 2007
Messages
233
Location
Lee's Summit, MO (Kansas City)
The first two RRDB entries list multiple CC freqs. Which one are you using?
For the second site (Lee Summit) I assume you want to treat it as a separate trunking system rather than it simply sharing TGIDs on the first system?
For the first two RRDB entries both are in my Trunk.tsv file on separate rows and OP25 alternates between the two entries in Trunk.tsv, currently Eastern Jackson County site is using 858.2125 Mhz and the Kansas City site is using 851.3250 Mhz.

I'm using two sites because even though the MARRS system is a large simulcast system covering Kansas City, many sites within the system only contain specific talkgroups. Here is what my Trunk.tsv file looks like.
88666

The new Lee's Summit site has its own TGIDs but shares some interop TGIDS within the MARRS System. The Lee's Summit site currently has very little traffic but the traffic that is there is what I want to listen to the most that is why I would give it a dedicated SDR dongle.
 

boatbod

Member
Joined
Mar 3, 2007
Messages
2,404
Location
Talbot Co, MD
For the first two RRDB entries both are in my Trunk.tsv file on separate rows and OP25 alternates between the two entries in Trunk.tsv, currently Eastern Jackson County site is using 858.2125 Mhz and the Kansas City site is using 851.3250 Mhz.

I'm using two sites because even though the MARRS system is a large simulcast system covering Kansas City, many sites within the system only contain specific talkgroups. Here is what my Trunk.tsv file looks like.
View attachment 88666

The new Lee's Summit site has its own TGIDs but shares some interop TGIDS within the MARRS System. The Lee's Summit site currently has very little traffic but the traffic that is there is what I want to listen to the most that is why I would give it a dedicated SDR dongle.
Ok that explains it thank you.

Really you want to monitor 3 systems and from site data it seems there is approximately 9Mhz spread from lowest to highest freq. With the newer multi_rx variant of op25 that means you either need 3 RTL devices (one for each site) or one high-end SDR such as an Airspy R2 to grab all the spectrum in one go. The disadvantage of the latter option is that it is (a) more expensive and (b) will eat up significant CPU with the USB data transfer.

Options:
i. Stick with the existing rx.py version of op25 and run two instances of the application with 2 RTL dongles and utilize the capability for op25 to jump between two control channels. Advantage: less dongles required. Disadvantage: you miss out on traffic with the switching back and forth.

ii. Convert over to multi_rx.py version of op25 and run one instance of the application with 3 trunking systems defined and 3 RTL dongles. Advantage: no traffic lost in switching. Disadvantage: needs a 3rd RTL dongle.

Either option can be configured to output audio to the same physical sound card device. It's going to get a bit confusing if you have multiple conversations going on at the same time, but as long as your brain can sort it out it will work.
 
Top