Bill Turner wrote:
Roy Lewallen wrote:

I hope this has encouraged at least a few people to think a little
before declaring every conductor to be either an "antenna" or a
"ground plane" and assuming that by doing so they'll somehow cause it
to behave in some predetermined and only vaguely understood fashion.

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A very good explanation, thank you Roy.

However... in your example of the giant tin can in free space, the top
of the tin can is acting like a ground plane, the side is acting like
an antenna and the bottom is again acting like a ground plane, just as
we have been saying. When this model is transferred to a car body, the
bottom of the car, in addition to the above, is also acting like one
plate of a capacitor coupling the signal to the earth below it,
commonly known as "ground". If someone disagrees with this I believe we
have a problem with semantics more than physics.

In other words, we are arguing over nothing.

Bill, W6WRT

I interpreted your comments and those by some others as claiming that
radiation from the car is insignificant, and that it therefore isn't
effectively part of the antenna. I attempted to show that this isn't
generally true. I also showed that coupling to the ground actually
increases radiation from the car. So either I've convinced you by my
illustration, or I misinterpreted your earlier remarks.

Roy Lewallen, W7EL