In article ,
"Richard Ferryman" wrote:

I have
never monitored the matching whilst mobile but guess it changed dramatically
when passing trucks, buildings, bridges etc. At best all one can do is
compromise.

Dick-

I've noticed some reduction in signals when going under an overpass, but
not as much as you might expect. The effect may be different for
different bands.

I accept the fact that I have a compromise antenna when mobile. Since I
don't have a remotely tuned screwdriver antenna, I stop the car and
change the antenna to change bands.

My current setup has a Hustler fold-over mast with an assortment of HF
resonators, mounted low on the side of the car. I use an LDG tuner.
The tuner works well on most bands, but only matches about 200 KHz on 75
Meters.

Your idea of using a matching transformer is interesting. If I have to
change resonators, I could change transformers at the same time. But I
doubt it would eliminate the need for the tuner.

Fred
K4DII