Hi Paul,
Boy, this does sound like a great place to mount a HF vertical. Bonding
each of the metal roofing sheets together with a short wire strap wouldn't
hurt anything, and seems prudent. I'd recommend "lag bolting" each leg of
the tripod into the 2x4 truss frames under the metal roof. Chances are you
can hit two of them without any problem. The third one will probably be an
issue, based on my installation of a tower tripod on my roof in the early
eighties. I'd investigate this, and maybe do some "engineering" by
installing additional bracing to accommodate the third leg, as well as
providing some additional structural support. I think the idea would be to
help spread out the various forces applied to the trusses. I'd consult a
contracting friend to get his opinion on the subject, too.
Best of luck! It sure sounds like a great project! By the way, I use a
ground mounted 4- band trap vertical in my backyard with success at the 150
to 200 watt level. But, it also has 24 each 30+ foot radials under it now,
too. I would like to say the vertical ISN'T a yagi or quad, but it works.
Just be sure to get a decent ground plane under them.
Good Luck and 73,
Steve, KZ9G/7
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Jim White, K4OJ
Sent: Friday, July 18, 2003 5:13 AM
To: Paul Carr
Cc: towertalk@contesting.com
Subject: Re: [TowerTalk] Verticals and Metal Roofs
Sounds like a great ground plane... you may have a luxury many try to
achieve with lots of radials!
Does the roof have good quality "seams" - I have heard reports of
intermittent contact between pieces of roofing causing SWR fluctuations
and fastners were needed to "hold it down tight"...
GL,
Jim, K4OJ
Paul Carr wrote:
> I want to install a vertical antenna on a structure with a metal roof
> using a tripod. What are the issues with mounting a vertical in this
> fashion?
>
> Does the antenna need to be mounted a certain height above the metal
> roof? Should the base of the antenna be grounded to the roof or should
> I strive for isolation? Can anyone describe actual installations?
>
> I assume that "insulated" radials will be required.
>
>
> Paul
> WL7PC
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers",
> "Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
> any questions and ask for Sherman, W2FLA.
>
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>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
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