so ive been messing with Winlink for about two weeks now and i cant get a stable connection to save my life. background: im running Winlink Express on a windows 10 machine, connected to a Signalink USB for the audio interface, and using a Kenwood TS-590SG on 40m. trying to hit a local RMS gateway about 30 miles away that I know is active because other guys in the club use it fine.

the session starts, i can see the handshake happening in the log window, it gets partway through the VARA FM negotiation (yeah i know i should probably try VARA HF but thats another rabbit hole) and then just... drops. sometimes it'll actually connect and start pulling messages then die halfway through. the partial messages dont show up in my inbox either which is annoying. ive checked my audio levels like four times and they look okay in the waterfall, not clipping, not too low.

anyone dealt with this kind of thing? wondering if its a timing issue or maybe the gateway itself has problems, or if my Signalink settings are just off in a way i cant see. the AGC on the radio is off already before anyone asks.

had almost the exact same issue last year and it turned out to be my transmit audio was slightly too hot even though it looked fine on the waterfall. the waterfall isnt really the right tool for setting TX levels for VARA, you want to use the VARA soundcard setup tool and watch the ALC on the radio itself — you want basically zero ALC movement. like none. even a tiny bit of ALC action will cause the kind of dropout youre describing especially mid-session when the protocol is doing its thing.

also worth checking: is your computer going into any kind of power saving mode that might be throttling the USB port? signalink runs over USB and ive seen weird timing issues crop up when windows decides to be clever about power management. go into device manager and turn off the power saving option for USB root hubs. sounds dumb but fixed my dropouts immediately.

30 miles on 40m with VARA FM doesnt really make sense, VARA FM is for VHF/UHF FM gateways. if the gateway youre hitting is on HF youll want VARA HF or Pactor if you have the modem. might be worth double checking what mode the RMS is actually advertising — you can see that in the Winlink gateway list, it'll show the connection types. that mismatch could explain a lot of the weirdness honestly.