Topband: Bev Transmission Loss

Richard (Rick) Karlquist richard at karlquist.com
Thu Dec 24 08:03:39 PST 2009


The problem with this concept is that first you have
to know your ground parameters.  What the NEC4 writers
suggest you do to find ground parameters is to first
run a wire(s) over ground and make physical measurements
of it to characterize the ground.  Then you fit the
model to what you measured.  Sometimes, it is impossible
to make the model fit.

I think you can now see that there is circular reasoning
going on here, and you might as well just build the antenna
and measure it and be done with it.  You could possibly
build a short beverage and measure that, and predict what
would happen with 2 W/L.  I know over my high conductivity
ground, there is virtually no signal left after 2 W/L.
I could predict this by measuring just 200 feet of wire.

Rick N6RK

Greg - ZL3IX wrote:
> Could anyone with access to NEC4 contact me off list please.  I am 
> looking for someone who would be prepared to model the transmission loss 
> of a 2 W/L Bev on TB, at 1.2m height and 2.4m height.  I have EZNEC 
> myself, but without NEC4, ground losses cannot be modelled.
> 
> 73, Greg, ZL3IX
> _______________________________________________
> 160 meters is a serious band, it should be treated with respect. - TF4M
> 
> 


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