[IrishJourno]

You're in luck! David Schneider, the author of this piece, also built a $150 hydrogen line antenna for us, based on a TV tuner SDR:

https://spectrum.ieee.org/track-the-movement-of-the-milky-wa...

:)

[bloopernova]

Unfortunately I'm in the middle of moving, but once I'm done with that, I'll give this a try :)