There is precisely one thing that keeps 198LW online: economy seven.
I think the reason why its been left on so long is that it took so long to migrate to digital meters https://tradehelp.gdhv.co.uk/support/solutions/articles/7900...
I am also annoyed that I missed the last signal.
The last signal will be on 30 June. It's (apparently) broadcasting a loop listing alternative ways to listen to Radio 4 now.
Not quite the same as hearing it live, but the final programme transmission has been recorded here: https://www.youtube.com/watch?v=QlflWWZpb30
I'm sad to hear the service has gone off the air. I was a constant listener to BBC Radio 4 on 198 kHz growing up in Dublin. It was a valuable window onto the world.
Listening to the last transmission there, I note that the continuity announcer, (the Irish) Al Ryan, signed off with 'oíche mhaith', i.e. 'goodnight' in Irish. A nice nod, I think, to all the former LW listeners in Ireland.