Radio Antenna (or not)

[BLUE49]

Its time for you guts to pull my bacon out of the fire (again). I've installed my original radio into my truck but really don't want to install an antenna. I was at the Dr. George car show today (1100 cars) and was describing my dilemma to the owner of a 49 chevy sedan. He used a device that plugged into the car's antenna port and into his cell phone. It works great and would solve my problem perfectly. Trouble is, I don't remember the name of the device, something RAD, Its this old age thing, I guess. As usual, I know one of you has the answer.