Has anyone ever heard of a radar detector named a Rad-A-Tec? It appears to be from the 1960ís. It has a baked enamel dark gray finish and is battery operated by two AA batteries like the old Radar Sentrys. It may also only be S band. It has a single orthogonal horn antenna and the back is made of plastic to pass the RF. It only has discrete components (can transistors, resisters, caps, and diodes) and not a single integrated circuit chip.
Here are some pictures:
Here is a picture of it opened up: