On Sun, 14 Nov 2010 23:58:47 -0600, "amdx" wrote:

http://www.hpfriedrichs.com/images-votc/gallows.jpg
If it's not self explanatory, you connect a stethoscope type headphone to
the tube that sticks out.

Not what I would call a megOhm Z candidate in any form as this is the
model for the commonplace 600 Ohm (telephone standard) to 1KOhm
headphone of antiquity. It uses a coil. You should be looking at
piezo.

So to rephrase my question, how do I raise the impedance of an antenna to a
very high impedance
with minimum losses?
MikeK

You could shorten the antenna to an inch or two for AM, but then it
would be shorter than your tank coil, and hence your tank coil should
be the antenna.

This was a toy commonly found in the late 50s when I got it for
Christmas. It was shaped like a Buck Rogers space ship with a ball
handled plunger as the nose cone that adjusted the ferrite in the core
of the coil (to be used as a tuner). Of course the longest wire was
the earphone lead (all of a foot or 18 inches which would still
constitute an extremenly high Z antenna that you seek).

I lived outside of San Francisco at the time, and AM stations were
unknown to it. However, I could get some Marine traffic like the
Coast Guard (I had a view of the Ocean from the hills around Pacific
Manor, now Pacifica).

Very uninspired performance to say the least.

73's
Richard Clark, KB7QHC