On Mon, 12 Jul 2004 11:51:53 +0000 (UTC), Harry Whitfield
wrote:

In article , isaac
wrote:

I understand that when used as intended the antenna uses the roof or
trunk of your car as a ground plane or counterpoise. (Are these the
same thing?) Some websites recommend sticking the antenna on a square
foot sheet of metal, but as this is Florida in the summer, I think our
usual midday rainstorms might blow the whole over.

Pending advice from the specialists, I'd be tempted to try a wire mesh
groundplane - something like the stiff wire mesh used in (cake) wire
cooling racks, with 1/2 inch mesh.

A ground plane need not be solid, as long as the holes are enough
smaller that the wavelength.

I don't think the size would be that critical providing the radius was
similar to the length of the antenna. Connect the wire to the iron bar
to which the antenna is attached.

The size is not critical, but ideal would be a radius of 1/4
wavelength. For a 1/4 wave antenna without a loading coil, that would
be the same as the antenna length.

Do the calculation yourself, but 1/4 wave at 800 mHz is about 3.51
inches.

Mounting your antenna on a 7" diameter disk would be optimal. Perhaps
that will be easier mechanically to work with.



Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom