Cecil wrote,

Tdonaly wrote:
Cecil wrote,
If the pancake coil is in the horizontal plane, it will probably
radiate horizontally polarized radiation and probably straight up.

It might. Do you want to tell us why you think so, Cecil?

Just off the top of my head - since the coil exists essentially only
in the horizontal plane, the radiation from the coil is likely to be
horizontal. If it is mobile, it is a very low antenna. Very low
horizontal radiation usually tends to result in an NVIS radiation
pattern in the far field. Hope there are no bugs in that logic.
--
73, Cecil http://www.qsl.net/w5dxp


The only way to be sure is to make or model this thing. I'd like to
make a point or two, though. 1. Since it's a coil, and a small one at that,
it would need current in order to make the B field which would produce
the horizontal E field which would define its polarity. The fact that it would
be
small and placed at the end of the antenna makes me think it would
be starved for current. 2. Since one end of the coil isn't attached to
anything, all it could do would be to accumulate and release charge. This would

create a changing E field, the lines of which, would end on the vehicle.
Since these lines would be roughly vertical, they might produce some
(probably undetectable) advantage in the radiation field. 3. A real
capacitance hat would probably do a much better job and be easier
to make. (How do you keep a flat coil from jiggling and
bouncing around like a clock spring as you're driving down the road?)
4. You might be better off thinking about ground losses in order to improve
your signal. Maybe a bigger truck would help.

73,
Tom Donaly, KA6RUH, COW (Certified Old Wife)