I have multiple nodes/repeaters using Masters Communications RA-42 interfaces.
Asterisk : 22.9.0+asl3-3.9.3-1.deb13
ASL [app_rpt] : 3.9.3
Individually, each has their audio levels calibrated reasonably well through the use of the "Interface Tune CLI" and a service monitor.
Is there a procedure for calibrating inter-node audio levels?
TIA
I have never found that to be an issue at all. If the node is setup using xxx-tune-menu your repeater is good to go. If you get low/high audio from another node that’s their problem not yours.
GeorgeC W2DB
I agree with George… I use RA devices in 9 repeaters, all set the exact same with simpleusb tune.. it is really difficult to tell which repeater you are coming thru… same level and quality. All my repeaters are kenwood tkr-850/750. Someone connects to me, some times I can tell by the way they setup their node.
I think the key point here is that inter-node traffic has no audio processing. What's received by the node is what gets sent to the next one. The tuning parameter are only for the channel drivers for in/out local audio. Beyond that... what you set at the origination is what you get until it pops out the other end's audio channel.
I use usbradio on all my radio based nodes (I don't like squelch tails, and you can't quite get rid of them with simpleusb on receive most of the time). Even with different radios and interfaces, so long as the radios are flat, I can usually get a consistent sound for RX and TX. It's everyone else, and other types of nodes I have to worry about. One guy on my system, for example, has a very distinctive, very long squelch burst on the end of received audio from his repeater. I don't want to be one of those.
Assuming Pipewire support happens at some point, processing for both inbound and outbound traffic would be (relatively )easy to implement if desired, possible additional latency notwithstanding.
I have been experimenting with using Analog_Processor from the DVSwitch project in place of one of usbradio or simpleusb to add things like AGC, RNNoise on RX, EQ and filtering, etc. Not many people use it, but it shows what could be possible. I'd love to have that kind of thing with closer integration, if nothing other than some basic leveling for just the voice, not affecting transmitted PL from usbradio if it is set up like that.. Having it available from app_rpt would also allow other non-usb interfaces, like voters, to have processing.
I guess this is all somewhat controversial, since adding this kind of functionality would give operators even more things to possibly break,, but I at least would be in favor of it, as I said, for nothing other than the ability to level out the dynamic range of other nodes coming into my nodes, since there is so much variation in audio level and quality.
All,
Thank you very much for your comments.
The repeater about which I receive the most negative comments is also the first repeater I installed with ASL. You have convinced me to redo the calibration (Interface Tune CLI + service monitor) on that repeater as I have learned much since then.
David, AK2L