So this arrangement moves the preform away from the tower leg? I am
rebuilding my tower and have three TIC rings mounted about 4 feet above the
guy mounts.
73, Keith NM5G
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Tim Duffy
Sent: Wednesday, October 2, 2019 3:47 PM
To: 'K9MA' <k9ma@sdellington.us>; towertalk@contesting.com
Subject: Re: [TowerTalk] EHS leads for Phillystran
I had a problem with just Preforms attaching to the tower legs connection -
which caused distortion in the pattern of close mounted Yagi's. That is,
Yagi's that were mounted only a few feet above a guy connection point. The
VSWR of the affected Yagi would change with rotation and the effect of three
Preforms connected to the tower was confirmed with modeling. The solution
was to use a bent pin shackle and an insulator right at the tower
connection. You can see it in this view of the middle four element 40 meter
OWA Yagi stack at K3LR:
http://www.k3lr.com/2016/ring.jpg
Using insulators at the tower connection completely solved the pattern
distortion and VSWR changes with rotation.
73
Tim K3LR
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of K9MA
Sent: Wednesday, October 2, 2019 4:20 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] EHS leads for Phillystran
i recently put up 70 feet of Rohn 25 using Phillystran. The first 4-5 feet
from the tower are EHS, to minimize the chance of something dropped from the
tower cutting the Phillystran. From the anchor up to about 15 feet
(vertically) above the ground is EHS. The rest is Phillystran. I never tried
to figure out whether the lower EHS sections are resonant, but they're a
long way from the antennas. Seems to work fine.
73,
Scott K9MA
On 10/2/2019 14:11, Ron WV4P wrote:
> Good afternoon !
>
> Having heard enough negative on the Polygon, we have shifted to
> Phillystran..
> What I have read says you must run EHS Leaders (I have Plenty in
> stock)
but
> not over 50% of the total guy length in EHS.
>
> Doing some modeling (not very good at) and reading, it looks like 41'
> of EHS would work well for not being resonate, being plenty high up to
> not worry about fire / vandals / beavers.
> 41' would also save a good bit of $ on the cost of Phillystran for 5
> towers.
>
> Any advice ? to long ? Just right ?
> Thanks in advance.
> Ron, WV4P
> _______________________________________________
>
>
>
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--
Scott K9MA
k9ma@sdellington.us
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