So ive been trying to get Winlink Express working for the past week and a half and im pretty much pulling my hair out at this point. The software itself installed fine and i can see gateways in the list when i do a channel selection update, but every time i try to actually connect to one it just sits there and eventually times out. Im using a SignaLink USB with my IC-7300 and i know the audio levels are set right because i can do Winmor just fine in test mode.

The issue seems to be specifically with RMS relay stations — the ones marked as telnet connections work perfectly fine so i know my account is set up right and messages are going through when i use that. Its just the RF side thats broken. My question is whether this is a PTT timing thing or if maybe im just not hitting the right gateways. Most of the local ones are 300 baud HF which i read somewhere is slower but more reliable? Not sure if that matters here. Anyone gone through this before and figured out what the stupid obvious thing i was missing was

Yeah this sounds exactly like a PTT delay issue. In Winlink Express go into your WINMOR settings (or whatever mode you're using, sounds like WINMOR from your description) and look for the PTT lead-in time. Default is usually way too short for a lot of rigs especially with a SignaLink in the chain. I run mine at around 300ms and that fixed a very similar problem for me on a 7300 actually. The gateway starts sending before your radio is even keyed up and it misses the handshake.

Also worth checking — what mode are you actually trying to connect with? Winmor 500 or 1600? Some of the smaller gateway stations only support one or the other and if the bandwidth doesnt match they just wont hear you properly. The 300 baud thing you mentioned is for Pactor on HF which is a different protocol entirely, you need either a TNC or an SCS controller for that. WINMOR is the software modem version that works with the SignaLink setup you have.

check your audio sample rate too, had the same problem and it turned out winlink express and windows were fighting over whether it was 44100 or 48000. soundcard stuff is always the dumbest possible reason for something not working