so, questions are 1) is there something special about a stock car radio ant i need to know? are they just a metal mast with a wire to plug them in, or is there some matching stuff built into the ant base?
Most of them are/were just a metal mast. They had a coax cable from the car body/antenna mount to the radio.
The only "matching stuff" usually is /was just a Hi input Impedance RF amp.
2) what if i just plug my long wire ant into it? should it work as-is?
It probably would work just fine on an older car radio that doesnt have a sensitive J-fet as the rf amp.
3) do i need to do anything to replace the effects of the 'missing' car body?
Not for the battery, the radio almost surely has a ground/negative power connection or wire.
For the antenna, YES YOU DO. Well actually you might get by without it but the car body was actually the "ground plane" of the antenna. The coax shield connected the radio case to the car body in most cases.
While you are gathering some car radios to try(auto junk yard?) grab some of the coax ant cables as well, or just make your own ground(RF not power) to the case of the radio.
i'm just hoping to catch some decent dxes on the am band between skeeter slaps out in the back yard. anyone have some experience with car radios like this?
Some car radios work GREAT on AM. They had to be better because inside of a metal car is just about the worst environment you can have for AM.
kb0lxy - Eric