In this video I'm trying to suss out how different radios process incoming signals and the role filter bandwidth plays.

Also, re: the issue of crosstalk when transmitting... I realize I had everything right on top of the radio and that this is maybe not ideal. I tried it unconnected to the switch and further apart, and the Kenwood still hears the R4020 (albeit at a much reduced level). The connected switch seems to increase it by some orders of magnitude no matter how close or far apart.