I picked this up having no idea what it was. I got it for a buck at the thrift shop, I saw a gpib port and F connector, the rest of the box is solid green steel, with a 4 pin power jack and key hole. when I opened it, it turned out to be some sort of transmitter... I cant find any data on it the FCC ID page doesnt even say much except its upper frequency is 845/890mhz. It is also marked audiovox cmt-3000 but is actually a Toshiba product... I thought at first maybe an NTSC transmitter but the frequencies don't match the RF channel list of frequencies.
I live near a military base, maybe its something goverment? I have yet to rip the shielding off because If what ever it is works... and is useful I would like to do something with it. Unfortunately I have no idea how much power to feed it or why there is 4 pins, nor do I have a machine with a GPIB port.
Any guesses are welcome all I can tell is it takes a key, and there is a duplexer along with a modulation, synths, and transmit section with a ton of Toshiba IC's mounted to the back.
EDIT: Not an F connector it is a reverse BNC like on old linksys routers.....