so ive been messing with Winlink Express for a few weeks now and i finally got it connecting to a local RMS gateway on 2m packet but the problem is it keeps dropping mid-session, like ill get the connect handshake and it starts pulling the message list and then just dies. Sometimes it completes but maybe 1 out of every 4 tries actually finishes and i can send or receive anything.

Running a TNC-X into an old Kenwood TM-261 and i know the radio is fine because i can hit the repeater no problem. Im wondering if its a timing issue or maybe my TNC settings are off. The gateway im hitting is only about 12 miles away so path shouldnt be the issue. Tried adjusting TXDELAY in the TNC but honestly im not sure what value im supposed to be at, ive seen people say anywhere from 200ms to 500ms and thats a pretty wide range.

Also a side question - for HF winlink is Vara FM or Vara HF going to give me better results on 40m for connecting to a Winlink CMS through a Telnet gateway vs direct RF? I know telnet kind of defeats the purpose but im still learning the message handling side before i go pure RF.

The TXDELAY issue is almost certainly your problem on packet. 200-500ms is a wide range but for most TNCs on VHF packet hitting an RMS you want to start around 250-300ms and tune from there. Too low and your radio hasnt fully come up to power before you start sending preamble, gateway never hears a clean burst. Too high and youre just wasting time and potentially timing out the session on the gateway side.

Also check your SLOTTIME and PERSIST settings if your TNC supports those - some of the older TNC-X firmware has defaults that are fine for BBS use but not great for RMS sessions which are a bit more time-sensitive in how they handle the protocol handoff. The Winlink side has a session timeout and if your TNC is being polite and waiting too long between retries the gateway just gives up.

On your HF question - Vara HF is going to walk all over anything else on 40m for actual RMS gateway connections. The vara HF soundcard modem is genuinely impressive for what it does, especially in marginal conditions. Telnet for learning the message handling workflow is totally fine though, thats how most people start before they care about the RF path.

yeah 12 miles on 2m shouldnt be the issue at all, sounds like a TNC config thing like the other guy said. one thing i dont see mentioned - are you running split frequencies or simplex? some of those local RMS nodes are on odd splits and if your offset is even slightly wrong you might be getting into the gateway but its not quite hearing you clean enough to hold the session together the whole way through. just worth double checking the exact freq and offset in Winlink Express matches what the RMS is actually on, the Winlink maps arent always 100% current on the technical details.