[TowerTalk] Taper changes using EZNEC+

[Steve W3AHL]

On 5/11/12 7:29 AM, john at kk9a.com wrote:
> I would like to change tubing diameters on an antenna that I have
> previously designed.  Is there a way do this and maintain the same
> element resonate frequency using EZNEC+?  I tried "Show Stepped Dia
> Correction" thinking it would be easy see how much longer or shorter the
> new element is, however there seems to be no way to make the new and old
> correction diameters identical.  It would be nice if I could set a
> standard taper correction size. Any suggestions?
>

I use Yagi Mechanical from DX Engineering for $39 (there's a free demo 
version to get a feel for what it does).  It does stress analysis for the 
elements and boom, but also keeps track of the elements' target vs. current 
resonant frequency as you change the taper schedule to get the required 
strength -- so you can adjust the tip length to get back to the target Fr.

It will load an EZNEC file, then you can save it for EZNEC analysis after 
the mechanical design is complete to verify the design is electrically 
equivalent to what you started with.


Steve, W3AHL