"Roy Lewallen" wrote in message
...
Tom Horne wrote:

FIRST QUERY/ANSWER SNIPPED (call it digital compression, Tom)


Are you being serious when you say that much of the difference in the
mobile rigs performance may be the vehicle on which it and therefore it's
antenna are mounted?

Yes.

IS the body of my half ton cargo van doing a substantial amount of the
job of radiating my signal?

Yes.

If I mounted the same antenna with the same mount on my Saturn should I
see a difference on a field strength meter that is the same distance to
the centimeter from the antenna over the same parking lot with the
antenna over exactly the same spot?

Yes.

Declaring a vehicle to be "ground" doesn't give it magic properties. It's
a conductor, just like the antenna. Exactly the same current that flows
upward on your antenna flows downward along your vehicle. The vehicle and
"antenna" comprise an asymmetrical dipole, and neither half is inherently
more or less important than the other.

Roy Lewallen, W7EL


Further, since Tom said his "B" vehicle in the test is a Saturn, I would not
even go so far as to claim that the vehicle is a conductor. The side panels
are plastic, though the frame on which they are mounted is metal. Check
with a magnet before you drill a hole to mount the base of the antenna!!