Steve, thanks for suggesting the obvious which I had blissfully overlooked.
Well, du-uh why not just give it a whorl? I’d suppose if it were an issue then
when rotating a directional antenna on that tower while monitoring my antenna
meter I would see variations in resonant freq or variations in VSWR or ohms of
impedance or some combination of the above if there were an interaction. If
the interaction is sufficiently large to be a concern then try breaking guys
into lengths that would not interact so much. It is a crank up tilt over so it
won’t be a big deal to fuss with chopping up the guys if needed.
When I put up my Hy-Gain Hy-Tower atop my barn I let my mechanical engineering
consultant talk me into a 4way Pyillystran guy system for an antenna advertised
as free standing. We also didn’t put a cubic yard of concrete into the base
mount system. I will save a lot of hassle and expense guying with wire and no
insulators with this 40 footer for VHF and UHF.
Thanks again, Steve.
73
Patrick AF5CK
From: Steve MIller
Sent: Tuesday, April 30, 2013 3:52 PM
To: Patrick Greenlee
Subject: Re: [TowerTalk] Non resonant guy considerations
Patrick,
I don't think I would worry much about it. I'm sure opinions differ but
try it without first and if everything plays well, go with it. If not, you can
always break up the lines. Lew Gordon did a study on hf and found that there
was little difference between having the guys broken or one solid piece. I
have an 80' tower with no insulators. My 2M5WL is 13' about that and I've had
no problem working the "dx" -- here that basically means east coast though I
have worked Wyoming, Texas, and New Mexico as well as Connecticut and other
east coast stations on 2M. (I must admit that was a few years ago but little
has changed on my tower since). Steve N0SM
From: Patrick Greenlee <patrick_g@windstream.net>
To: Tower Talk List >
Sent: Tuesday, April 30, 2013 3:10 PM
Subject: [TowerTalk] Non resonant guy considerations
August gentlemen of the elevated antenna mounting structures fraternity, I
would like some technical advice (and anecdotal reports are also solicited
as well) regarding the necessity/effects of breaking up the guys for a tower
used for VHF and UHF into non resonant lengths. The subject tower is a
tilt-over/crank-up tower consisting of two 20 ft sections and a tube mast at
the top to gain back the length lost to overlap and have antennas mounted at
least 40 ft AGL
This tower is intended for use only to support VHF and UHF antennae but may
have a non conductive connection (black Dacron antenna rope) to assist in
holding up a wire antenna or portion thereof in the HF bands. Any thoughts
on how far the antenna wire needs to be from the VHF and UHF antennas. HF
and VHF/UHF will not be in use simultaneously.
At some point as freq goes up breaking up the guys into ever decreasing
lengths is not standard practice, e.g. microwave and cell towers. So, any
advice as to approximately about where in freq this "happens" for ham bands?
Yeah, I know, how high is up and how long is a ball of string...
TIA for your consideration and 73 de
AF5CK Patrick
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