Boredom got the best of me: AA5 hum and loop antenna

[JohnCT]

Originally Posted by Kevin Kuehn

And if you notice on the schematic they show an earth ground symbol for the external antenna, which is not chassis ground. In theory when it's wired correctly you would have your antenna on one end of the isolated loop and earth ground(water pipe) on the other. Doing that should isolate anyone touching those two connections from shock hazard. Unless of course there's a capacitor shown on the schematic connecting those two grounds, which I didn't notice with my quick scan over. Make sense?

I'm not sure what you mean.

The antenna fiberboard has three wires exiting the board: two form the continuous race track loop, one end of each ending up at the grids of the osc tube and first IF tube like most AA5s. Typical stuff at this point.

The third wire on the antenna fiberboard is a single trace that lays alongside the edge of the racetrack loop. One end of that wire is terminated and literally buried into the fiberboard where no electrical connection can be made to it. Looks like it was punched in with a tool. The other end is connected to a wire which presumably is the wire that would serve as the external antenna lead in.

Do you mean that single lead would go to an antenna, or to an earth ground? It wouldn't be possible to connect that isolated track on the antenna board to both an antenna and an earth ground.

Thanks again.

John