The AM Forum

now that it is getting cold antenna it is ant WX. I've decided to do a little simulation driving.  I'm seeing some interesting results with a pair of phased diploes spaced quarter wave apart with a passive director in the middle.
This really drops the operating Z but adds some interesting performance. Looks like a 4:1 transformer at each driven element will jack the input Z back up.

Any details on forward gain?  FB ratio?  I have operated with co-phased dipoles for 75M in the past ,but never with a center element.  I want to put up another set aimed SE so I am interested in your modeling results...  Steve

If I cut the elements real short the FB is impressive but the input Z goes way down. Still need to study it some more. I am impressed with Brent's phased dipoles. Maybe it was conditions today of the distance between us but his set up rocks.
I also want to try feeding all three elements with a 1:3 Splitter. The center element phase would never have to chance so the switching network would be the same just the delay line length would change.

Q becomes a hard issue to deal with Frank. I'd be curious to see what the model looks like. How high can you get the antenna? I would avoid anything less than .2 wave spacing unless you have one frequency in mind. Parasitic elements in the horizontal plane below 55 feet have to much ground coupling on 80 mtrs. Delta loops look promising with parasitic configurations due to vertical components.

Parasitic designs have pattern flip issues from bottom to top of the band. So I would be curious what ur thinking.

Brent W1IA

Yes I see the pattern flip at 3.9 MHz and it gets real nice at 3.5 with a 100:1 VSWR.