Doug, what you describe is similar to what I have been using.
I first installed a 80m 1/4 vertical. Its free standing tapered aluminum 3"
to 1/4". Mine is over 60 radials about 65 in length. There is an inductor
across the feed point that acts as a static bleed and helps with matching
on 80m.
My inverted L takes off at an angle from the shared feed point (20 to 30
degrees to the vertical) and goes up to a point about 45 feet high
(supported by a nearby tree) from there it goes horizontal (actually about
10-15 degrees above horizontal). Ultimate length was trimmed for resonance
on 160m. The 'horizontal' portion of the 160m element is separated from
the 80m vertical element by at least 5-6 feet. At first it didn't work at
all, but after installing a balun at the base it has been getting along
nicely. I never increased the radial length beyond 65 feet, though I would
if I had the space and were planning to stay at this location longer.
It has been working great on 80m and 160m. No noticeable affect has been
observed on 80m performance after the addition of the 160m element (I think
I re-tuned the length of the 80m vertical slightly and maybe changed the
impedance of the coil at the feed point); I've never taken the 80m element
down to compare 160m performance it to 160m alone.
I plan to take this antenna down in a few weeks as I am changing QTHs, I
plan to fully measure and model this antenna before it is disassembled.
Feel free to bug me about this in the future if I forget to post it.
Greg N2GZ
On Wed, Mar 22, 2017 at 12:08 PM, Doug <doug49707@gmail.com> wrote:
> Guys
> I have a 75-80 1/4 wave vertical. It has 20 1/4 wavelength radials. I
> would like to run an inverted l up the radiator and horizontal for the rest
> of the radiator both antennas fed with same feed line I would double the
> number of radials and also double the length. Are there any problems with
> this type of operation
> Doug. WD8Z
>
> Sent from my iPhone
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