If it has to take very high winds and you don't want to be servicing it, a
commercial (as opposed to amateur) VHF beam might fill the bill better than
what we normally use, because the big-name VHF antenna manufacturers, e.g.,
M2, make very, very lightweight antennas which may eventually wrap
themselves around your mast -- although I've seen many of them survive
repeated 70mph winds. I just don't know what happens at 100mph+, it might
get ugly.
The old KLM (now long gone) 2m yagis were quite heavy-duty compared with
most of what's out there today.
I might opt to use an M2 model 2M9FM, which is a 14.5' long, 9 element,
FM-section optimized yagi with a T-match and balun (which work very well,
and are extremely weatherproof), and simply reinforce the center boom
section, which is only about 1" extruded, thin-wall aluminum as factory
stock. By adding long sections of thicker aluminum plate for 18-24" either
side of the mounting, the antenna would likely survive very high winds.
And, at least the darned thing works very well if it stays up.
Note you really don't want any VHF vertically polarized beam installed with
a metallic mast sticking up through it...
WB2WIK/6
"If everything seems under control, you're just not going fast enough." -
Mario Andretti
> -----Original Message-----
> From: david cretty [SMTP:dcretty@mindspring.com]
> Sent: Saturday, November 16, 2002 10:01 PM
> To: towertalk@contesting.com
> Subject: [Towertalk] 2 meter fm antenna
>
>
>
>
>
>
>
>
>
>
> -Any recommendations on a 2 meter beam for distant fm repeaters? It will
> be placed on a 64 ft tower about 5 ft above an hf beam. I have been
> looking at the arrow antennas and m2. Also the the tower is the open and
> subject to high wind. Any advice would be appreciated.
>
>
>
>
>
>
>
>
>
> --- StripMime Report -- processed MIME parts ---
> text/html (html body -- converted)
> ---
> _______________________________________________
> AN Wireless Self Supporting Towers at discounted prices,
> See http://www.mscomputer.com
>
> Wireless Weather Stations now $349.95. Call Toll Free,
> 888-333-9041 for additional information.
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
|