[Elecraft] AX1 Loaded Whip Antenna - Elevation and

[David Gilbert]

I'll try not to beat this into the ground here, but I think the physics 
here is important.

As K9YC said in his reply to you, equal currents go in both directions 
from the feedpoint ... to the AX1 and to the counterpoise wire.  That's 
simply physics, and it's true unless currents on the shield of the coax 
cause imbalance ... in which case the coax is doing a bunch of radiating.

Now then, what is important is what happens to those equal currents.  It 
doesn't matter if one side of the feedpoint is the AX1 or if it is the 
"counterpoise" wire ... they are both simply loads as far as the 
feedpoint is concerned.  Read that again ... it is THE critical concept.

Current generates a radiated field.  That is simple physics. Resistive 
loss dissipates energy instead of radiating it.  That is also basic 
physics.  To a lesser extent, current distributed over a longer length 
is a more effective radiator than a shorter length even disregarding 
impedance concerns.  Consequently, a short, lossy "load" is going to 
radiate less RF than a longer, less lossy "load".  Straighter is better 
than snaky.  All of that is fact.

Unless you have a very short counterpoise wire it is going to try to do 
a better job of radiating RF than the AX1 if you give it a chance.  Keep 
it as straight as possible and keep it clear of ground and other RF 
dissipating structures.

That doesn't mean that the AX1 isn't serving a very useful purpose. It 
is.  It is allowing you to feed current into the "counterpoise" wire 
with a reasonable feedpoint impedance.  That's critical.  But it doesn't 
mean that the AX1 is doing the bulk of the radiating unless you aren't 
using a counterpoise at all.

Hope this helps.  73,
Dave   AB7E




On 8/27/2019 2:29 PM, Grant Youngman wrote:
>
> I’m not saying that an elevated counterpoise won’t work with the AX1, just that I’m having trouble getting my head around considering the wire as the main radiator, and the AX1 as a counterpoise???
>
> Grant NQ5T
> KX3 (8342)/KXPA100
>
>