https://www.kkn.net/dayton2008/multi-element%20lowband%20verticals%206.pdf
Also:
Antenna book / on4un book:
a. 4 or 5 bent verticals from tower.
Initially from YCCC guys.
b. coaxes to center switch.
c. coax length to be inductive
to create reflectors for non-fed vertical.
Also
Could use poles / ropes / other outrigger
to move top of verticals from top of tower.
Am on PC at this ridiculous Eastern Time
for something else. Hence, no direct references.
Bob, w3idt
.............................
. Robert F. Teitel, W3IDT .
. .
. W3IDT@arrl.net .
. W3IDT@comcast.net .
.............................
On 9/18/2020 8:35 AM, john@kk9a.com wrote:
I am not sure how accurate this is but I usually model the tower as a
large diameter wire and I only include the boom of the top antenna (I
use insulated elements). K9RS has an interesting article on using bent
wire verticals around a tower
https://www.kkn.net/dayton2008/multi-element%20lowband%20verticals%206.pdf
John KK9A
k4xs wrote:
Plans are VERY slowly progressing for my new station in Belize. Plans
are for a 106 foot tower with lots of goodies on it.
Here's what is planned:106 ft of Rohn 55 guyed with Phillystran. Three
swing armed Skyhawks at 32, 64 and 96. Two A3WS WARCs at around 76 and
42 ft. I plan on running four ropes to hold a wire 4 square surrounding
the tower. This is similar to what I had in KH6 and the 4 square worked
well although the F/B was down to around 10-12 dB.
My question is this: I know the tower will have some effect on the 4
square surrounding it. Obviously I don't want the tower to be anywhere
near resonant on 80. My guess is the top loading of the tower will
lower the resonant frequency quite a bit, and the effective height will
be around 145-150 ft, but I am not sure. Obviously if it is in the
range of around 130 it would be a big issue.
There is not enough room to put up a 4 square by itself so I'm stuck
with this set up. I do have some fiberglass poles that I could attach
to the tower vertically to give it another 13 feet or so by running a
wire up the pole and attaching it to the tower, but I really don't want
to do that if I don't have to.
Thoughts on this?
73 Bill K4XS/KH7XS
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