In article ,
Jeff Liebermann wrote:
On Tue, 25 Apr 2017 22:38:56 -0700, Jeff Liebermann
wrote:

Sheesh. I'm an idiot. I just noticed that I already have a model of
an alternating coax collinear on my own web pile:
http://802.11junk.com/jeffl/antennas/CoaxVert/index.html

I fixed a few things, made some better images, and renamed the folder:
http://www.11junk.com/jeffl/antennas/CoaxVertical/index.html

Looks like the 1/4 wave section at the top is missing. I'll fix it
tomorrow. It's late, I'm tired, etc...

Thanks! I'll pull down this model, read through it so I understand
it, and run a few sims myself.