so ive been fighting with this for about three weeks now and im at my wit's end. background: i have a remote station running at my parents place about 80 miles away, IC-7300 hooked up through RemoteHams RRC-1258 mkII, and separately ive got a local repeater linked via EchoLink into the system so club members can monitor HF from the club repeater. sounds complicated because it kind of is.

the problem is the audio drops out on the SDR side specifically. not the rig control, not the PTT, just the audio from the SDR receiver i added last year (its an RSPdx running SDRuno via virtual audio cable to the RemoteHams software). the drops are random, sometimes every 20 minutes sometimes three hours go by fine. ive already checked the obvious stuff - cable between RSPdx and the PC up there is solid, VAC buffer is set to 500ms, the internet connection at that end is fiber so its not a bandwidth thing.

what im wondering is if the issue is somewhere in the audio routing where the EchoLink client is also trying to grab audio resources at the same time. both are running on the same machine up there which is probably my first mistake. anyone dealt with something like this or have a sane way to isolate which part of the chain is dropping the audio?

yeah running EchoLink and your SDR audio on the same machine is asking for trouble honestly. windows audio session management is just kind of garbage when multiple apps are competing for the same virtual devices especially if VAC is involved. ive seen VB-Audio Cable do weird things when another app briefly grabs exclusive mode on the device - it just silently drops samples and you dont notice until the stream completely falls apart.

what i would try first is setting the SDRuno audio output to a dedicated physical USB audio adapter instead of routing through VAC to RemoteHams, and leave VAC only for the EchoLink path. it adds a tiny bit of latency but the streams stay isolated. also check if SDRuno or the RSPdx driver has any power management stuff on the USB port - windows will sometimes throttle USB audio under load and with an RSPdx doing wideband that port is working hard. device manager, USB root hub, uncheck allow computer to turn off this device. probably wont fix it completely but its a good first step before you start pulling the whole chain apart.

i had something almost identical last summer except mine was just the RRC without the SDR part. turned out to be a QoS issue on the router at the remote end - the audio packets were getting deprioritized whenever anything else on the network sneezed. parents house by any chance? lol. they probably have a consumer router that doesnt do proper QoS and the audio UDP packets just lose the race whenever someone streams something. the RRC audio is pretty sensitive to jitter even if overall bandwidth is fine.

anyway might not be your issue but worth checking. fiber doesnt mean the router isnt the weak link.