I (used to) use simonsaysai.com to generate subtitles and they had the functionality to input specialized vocabulary, so I suppose it's possible in some sense but I don't know how it would work with Whisper, something to ask on their Github if nobody else has yet I suppose.
But, for me, the English model works really well. Using the 'large' model works about perfectly for me, I can't think of anything I thought the large model got too badly wrong, is that the model you tried?
Yes, the problem is that the radio chatter is just very, very low quality, for a lot of words your brain just needs to know the context to fill in the gaps due to radio static and such. Even as a human some parts are unintelligible.
Yeah it's a hard case, Whisper with the large model is among the cutting edge in the business so if the static is bad and the quality is low there's not much you can do but wait for better AI, or fix whatever they get wrong by hand, but Whisper AI is on the cutting edge so you might have to wait for a bit lol
But, for me, the English model works really well. Using the 'large' model works about perfectly for me, I can't think of anything I thought the large model got too badly wrong, is that the model you tried?