H. Adam Stevens, NQ5H wrote:
"Cecil Moore" wrote in message
et...
Roy Lewallen wrote:
I don't see any information at that web site about the type of vehicle.
Since the vehicle radiates an amount comparable to the antenna, it can
have a profound effect on the overall field strength. Were all those
antennas mounted on the same type of vehicle?

Those are averages, Roy, not associated with any particular
vehicle. The average screwdriver beats the average hamstick
on 75m. Using similar antennas, the larger vehicles (GMC
pickups) usually beat the smaller vehicles (Honda Civics).
--
73, Cecil http://www.w5dxp.com

Makes sense.
Also confirms my experience.
I've also found optimum performance driving the antenna where it's resonant
and matching the (purely resistive) impedances with a transformer.
In this case a simple toroidal autoformer. At 40 meters, a Tarheel
screwdriver with a five-foot whip is about 20 ohms, for example.
73
H.

First time I noticed this was in the early 70s after I put a CB radio
on a school bus camper. The same radio and antenna had been on a
Volkswagon before. The difference was very noticable.