[TowerTalk] worlds biggest yagi

[Jim Lux]

Pete Smith wrote:
> Another notion that occurs to me is that with the Steppirs, you could 
> detune some of the antennas at any given time.  That *might* produce a 
> situation where you could run, say, an 8-high close-spaced stack 
> (optimized for 10 meters), and then "remove" some of the antennas from 
> the stack for 15 and 20.  You'd still have $3-400 K left for land.
> 
> The idea of individually tuning the antennas (on each band) to 
> compensate for their distance from ground (or from each other) is 
> intriguing.  I have always wondered how you could put identical yagis in 
> an HF stack and not be giving away something in gain or pattern.
> 
> 73, Pete N4ZR

It's really no different than tuning the elements on a single boom.  The 
challenge, I've found, is setting up an appropriate goal function for 
the optimizer.  This is not much different than the currently 
fashionable ESPAR arrays for wireless work.  (A single driven element in 
the middle of a circle of passive parasitic elements with varactors on 
the parasitic elements)