When I was a kid (late 60's, early 70's), there was an indoor antenna, usually advertised in comic books. It was a small ribbed either grey or beige in color cylinder, about the size of a roll of quarters, with a flat 300 ohm two conductor wire lead that you attached to the VHF screws on the back of your tv. At the bottom of the cylinder there was a two blade connector that had one metal blade and one non-conductive plastic blade that you plugged into any ordinary electrical outlet. It was supposed to turn your whole house wiring into a more effective antenna. I was trying to remember what they were called and who sold them, but I can't find any mention anywhere on the internet of these things. Does anyone have any info or pictures on these? It's driving me crazy that there's nothing about them anywhere.

Thanks guys!