(whatever is left of) My brain is straining quite a bit to remember those
EE classes, so this may not be totally accurate, but I think it has to
do with the impedance of the antenna that the CB's electroniccs are tuned to.
In other words, no matter how 'big mutha' the amtenna is, its apparent
impedance should also match (that of the CB's internal).  Playing with 
the geometry, dimensions, etc..., should help.  One thing:  in general, 
antennae sitting parallel to road surface is not as efficient as vertical
ones, the reason having to do with wave propogation close to Earth's surface,
etc., etc...

The antenna itself does not have to be made of real thick metal.

Good luck, let us know of the results.

Cetin

 > hmmm. that's a thought. anybody know anything about "loop" antennas? like

again, The trick is having the loop vertical rather than horizontal to get
more reception.  How about one around the bay window?

 > having one big loop around the inside of the pop-top? if it works for the
 > old tv sets, why wouldn't it work for a cb transmitter??