[EdHolland]

Chas,

Thanks for the detail. I know in general about antennas, and the efficiency that comes through resonance. Receive is a bit more forgiving than transmitting, but the principles still hold of course.

I found one article that IIRC showed how one of the designs (not Philco I believe) flattened out the response curve.

The other articles I found indicate that the intention was that the antenna could be placed outside, and the balanced lead-in could approach the house without picking up the near field interference from domestic wiring etc. like a simple long-wire would have done. The designs also helped prevent the radio from conveying wiring noise out to the antenna.

This is indeed something that could be a thread all its own, because the isolation methods using transformers do still work brilliantly, especially in keeping the antenna and house wiring separate.

Cheers

Ed