This isn't my field, so please forgive any misnomers on my part.
I'm looking into buying a amateur radio receiver, and I'm thinking about what sampling rate I need. I'm most interested in satellite signals, which transmit on ~400MHz (for example). So that would imply I have a nyquist frequency of ~800MHz, or 800 million samples per second. This seems much higher than any hardware I can find.
My current thinking is that the frequency to be used in the nyquist calculation isn't the carrier frequency. Which frequency should I use?