...unless it's a $20 plasma disc, apparently.

That would work. How are you connecting the output of one to the input of the other? If your connector has two or more contacts, you can use one of them.

I don't have a jack soldered into my APC yet (still working on the enclosure), so I just stuck the output wire directly into the breadboard for the Amp.

I guess it makes more sense if I think of it in that context though.

Will grounding it correctly improve the RF situation? Although I think I was having that even without the APC connected.

Most likely- were you actually receiving a radio station?

Yes.

That's pretty awesome, I'd say leave that one broken and start over and make a non-radio, or an amplifier to amplify your radio.

I finally got around to trying it this morning, bridging the grounds fixed it, it works great and the RF went a way.

Yeah it's pretty cool (for a noise inclined guy like me anyway), I was just listening to it again, it actually sounds like a couple of stations overlapping, AM band I suppose.

VERY cool. It was almost certainly AM- AM radio is quite easy to pick up and decode, both because of the very low frequencies involved (it tops out well below 2MHz, which is practically DC as far as weird high-frequency behavior is concerned) and because it's such a simple modulation scheme.

In fact, if I stretch my memory back to my communications class, the simplest AM receiver is basically an antenna with an amplifier feeding a diode with a low-pass filter attached. REALLY easy to make, and in fact, almost exactly what you have there.