[TowerTalk] Matching network for wire antenna needed

[Jim Lux]

On 9/14/14, 2:47 PM, Doug Smith wrote:
> You can match both 160 and 80 with a single “modified” L-Network.  It would have three components rather than just two.  There would be no switching required moving from 160 to 80.
>
> But, you’d likely need TWO of these networks — one for the bottom end of the bands and one for the top end of the bands.  With remote switching to flip between them.
>

Theoretically, one can design a network with a sufficient number Ls and 
Cs to get good match anywhere.  It's not quite as simple as two narrow 
band networks with a switch, but it will be the same number of total 
components.

There's a fair amount of literature in IEEE Trans on Ant and Prop from 
the 60s and similar journals with the equations and design principles. 
Look for "broadband matching network".  I seem to recall seeing papers 
about techniques to match the whole HF band into a dual resonance whip 
antenna without relying on a big amplifier and loss.


One has to watch out for pathological scenarios with a lot of loss, but 
these days, with computers to do the model, it's fairly straightforward 
to do the optimization.