Richard Clark wrote:
On Thu, 27 Sep 2007 20:21:38 -0500, Mike Coslo
wrote:

There is at least one 2 meter Frequency that kicks me out of overdrive.

Hi Mike,

The cabin of a car or truck makes a fairly poor Faraday Shield to 2M.
Try as you might to correct things through a choke (conduction), there
may still be problems (radiation).

It is at this point that most vehicle owners discover all those parts
of their vehicle that are NOT grounded (or, rather, continuously
shielded). Hoods are usually floating with respect to the chassis and
make a great capacitor to the interior of the engine compartment.
Exhaust systems similarly float and are sometimes resonant in upper
HF. Doors hinge on plastic bushings... and the list continues.


I have read about the need to use some copper braid to ground a lot of
the parts on the car. The exhaust system is certainly around the length
of the antenna mast in itself.

- 73 de Mike KB3EIA -