Antenna Connector

[LovesZenith]

This one is kind of an strange question, but this seems to be the best place to post it. I recently acquired a 19" tin can Zenith (my first tube set, but that's another post for another day) and it still has it's rabbit ears on the top of the set, it has the little pitchforks to screw onto the back of the set. A while ago, in a video on YouTube, I saw a device that you screwed the pitchforks into, and then you could plug it into the modern day out puts on your converter box. It let you use the original/analog antennae built into the set. It was just a nub really, with two screws on one side, and a cable out put on the other. Does anybody here know what I'm talking about, and what it's called? I went to two different Radio Shacks, and one only had converter boxes, and the other had the things that you screw onto the back to plug a cable into. I hate that I can't find the video I saw it in, because I remember them saying what it was called. So, if anybody know what I'm talking about, please leave the name so I could order one online.
Thanks,
David