[TowerTalk] Fan dipole Re: Looking for a HP 80/40 Duplexer

[Jim Brown]

On 11/18/2025 7:50 PM, john at kk9a.com wrote:
> When I saw fan dipole listed as the 40/80 antenna I was thinking of a
> homebrew dipole with separate wire elements attached to a common center
> insulator (and maybe choke).

Since we can't do attachments on this reflector, I'm posting a link to a 
pdf of VERY old slides for a "practical antennas" talk I did for a local 
club soon after moving to W6. Page 11 shows the loading coil for an 
80/40 loaded dipole, pages 15 & 16 show current distribution. Pages 26 
and 27 show the first fans I built after moving here. This was an 
antenna sold in the back of QST by a guy in PA, that I bought when I was 
getting back on the air in Chicago in 2003, and didn't have the stash of 
stuff to build something. The loaded design just fit between the two 
points where I could get a friend to rig it (the roof of the house was 
WAY too steep for me).

http://k9yc.com/LimitedSpaceAntennasPPT.pdf

BTW -- I've changed my thinking about the effectiveness of vertical 
dipoles after the extensive modeling study I did about ten years ago, 
showing the dependence of verticals on soil quality. Ground quality at 
my QTH is really poor.

73, Jim K9YC