What is a good programmable easy cheap radio device I can buy and plug into a USB port of my computer?
Discussion
wifi dongle, bluetooth dongle
what do you mean "radio" - radio uses protocols
Rtlsdr
KNAC.COM
Baofengs and the like can be plugged in to PC w/ USB cable. Can send to you one for 40ksats π
I second the RTL-SDR. Just about limited to your creativity with antennas. FOSS SDR software on linux.
I would get something that has the ability to send, maybe a bootleg hackrf one, check out GNU Radio Companion (GRC) and spread your wings.