CaribouLite SDR HAT for SDR on a Raspberry Pi
A couple years ago, after I heard about the CaribouLite on CrowdSupply, I pre-ordered one.
I've dabbled in SDR with an RTL-SDR v3 for a few years, even using one with nrsc5 to listen to baseball games OTA because of silly MLB blackout restrictions.
But low-cost SDRs like the RTL-SDR v3 are receive-only, and have a limited frequency range, and lower quality RF filtering, so it can be frustrating if you're trying to work with lower-power RF... or trying to transmit at all!