DSDPlus Not receiving all sites ICORRS

[saioke]

What is the best/easiest way to determine the ppm error for the RTL-SDR v3?

Probably not the most convenient way but I've used DSD+ Fast Lane to do that as well. Just turn on auto-ppm by pressing a. Make sure DSD+ is tuned to a good p25 signal. You'll see a number jumping around next to the frequency in the fmp24 spectrum window. You either raise and lower your ppm by pressing P/p and the goal is to reduce that auto-ppm number down to as close to 0 as you can get.

But if op locks a b c tg’s in one instance, and they don’t affiliate with the other instance, then those don’t get captured/heard.

I guess it depends on the tg because I notice several talkgroups in my area personally affiliate with the same traffic on multiple sites. Could be because the sites are so close to each other, not sure.

 

[bburkett]

Thanks for info! Looks like a lot to learn!!!

 

[saioke]

I Initially forgot to include a screenshot but as you can see above, next to frequency 774.53125, is -133 hz. This number will show when auto-ppm is enabled. 100-200hz is typical I'd say, you just don't want these numbers to exceed the thousands, but closer to 0 is good. That ppm is my sweet spot for that particular SDR and I can't get any lower. It ultimately depends on how good your SDR is, but every SDR will have ppm differentials. Some are worse than others. If you have a cheap SDR with no TCXO, you could expect to change your ppm to +/-30 or more. Both of my SDRs are the RTLSDR v4 and both of them require different ppm correction.

But when adjusting, as you can see, that number is -, which means you should increase the ppm. If it's +, decrease it.

When it's adjusted, I like to turn auto-ppm off because it seems like I get better/clearer decodes without it. But, a lot of people just keep it on.

 

[bburkett]

Thank you! You have really helped!!
~Bob

 

[DaveNF2G]

Yes but if you're running two instances from the same folder, they both use the same .groups file don't they? So setting priority in one instance would also change priority of another?

Hmm. Yes, that is a problem. However, cg's suggestion above will fix that.

 

[n3obl]

If you are in south central cambria you may be too far to hear an eastern westmoreland or fayette tower.

Now just cause you can hear talkgroups on cambria site is irrelevant as you need to be able to switch to the control channel for the other sites.

You need to read up on how trunk systems works etc.