What SDR did you use that has the bandwidth to capture the entire airband? You need to scan about 20MHz for the voice channels.

What STT system / model are you using?

I had a plan to try something like this from where I live, but I wasn't sure how to solve those two problems.

If you're trying to build something that integrates with the Linux desktop, check out dabri https://github.com/AshBuk/dabri

Not mine, I just found it 2 hours ago.. No mention of it on HN so not sure what others think about it.

He listed some technical details here: https://news.ycombinator.com/item?id=50491176