On Thu, May 2, 2013 at 5:23 PM, Patrick Greenlee
<patrick_g@windstream.net>wrote:
> I think I got it... Phillystran (or other non nonconductor good... steel
> bad...
>
That's a gross oversimplification. There's applications for both of them. I
have 3 towers; two are guyed with EHS, broken up with insulators, and the
third - a rotating tower - is mostly guyed with Philly. I used the
non-conducting guys because I have stacks for 10, 15 and 20 side-mounted on
that tower and the possible complications called for Phillystran - it was
simpler to go non-conductive than to do the modeling.
One of the other 2 towers is mostly used for a 40 stack and a simple 80
meter wire. I can detect no guy wire interaction with the top, rotating 40,
and I have always presumed that meant that the lower, side-mounted (fixed)
40 was also not affected, but I could be wrong. The array works FB, so I
don't feel the need to investigate further.
The third antenna is a base-insulated, full-size 160 vertical and it's
installation is probably typical of most every other 160 Rohn 25 vertical,
that is, it looks like a broadcast stick - EHS broken up with insulators.
It might be instructive to visit a few guyed towers used in the VHF/UHF
land mobile world and also some guyed cell towers, if you can still find
any of those. I have spent a lot of time working at 2-way sites and I can't
recall any of them guyed with anything other than steel - and NO insulators.
One final observation, perhaps important if you do your own climbing: A
tall tower guyed with Philly definitely moves more than the same tower
guyed with EHS, so it will feel different in your gut when you're working
up there. Spend some time on K7NV.com to get a feel for the "stretchiness"
of Philly and the corresponding changes in the forces at the base of a
guyed tower.
Horses for courses, as they say...
73,
geo - n4ua
>
> Anyone with a reasoned opinion re my question regarding VHF and UHF
> antennas on a tower? At some point breaking the guys into non resonant
> lengths becomes nearly impossible as wavelength gets shorter and shorter. I
> wonder about at what freq it is no longer needed?
>
> Patrick AF5CK
>
> -----Original Message----- From: Jim W7RY
> Sent: Tuesday, April 30, 2013 10:00 PM
> To: Crownhaven ; towertalk@contesting.com
> Subject: Re: [TowerTalk] Non resonant guy considerations
>
> I don't think I would ever use steel guy wires again.
>>>>
>>>
> Steve, N4JQQ
>>>>>
>>>>
> I absolutely agree!!
>
> 73
> Jim W7RY
>
>
> On 4/30/2013 4:50 PM, Patrick Greenlee wrote:
>
>> 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
>>
>
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