I agree totally with Pete. The Hexbeam is a compromise 2 el yagi with
bent wire elements. It could not possibly compete with a conventional
yagi with full size straight elements. The KT 34 class beams are proven
performers but take more maintenance that non trapped yagis such as F12
and Bencher build.
You did not mention if the roof is metal or not. Even if it is metal,
don't despair. Yesterday I worked the P5 on 15m in a big pileup using a
F12 4BA at 50 feet over a metal roof building. The tower is house
bracketed to the end of the building. The roof is 30X50, 15 ft at the
peak.
I use an extension ladder to work on beams on my 2 crankup towers in
the nested position. Without guy wires to worry about, it is duck soup
to install yagis on nested crankups.
73, Dan, N5AR
Pete Smith wrote:
>
> At 06:17 AM 1/27/02 -0600, Barry Baker wrote:
> >
> >Hello to the group. My call is KC0LCL. Given a choice of running a Hex-Beam
> >at 40' which is its reccommended height or Something like the KT36XA from M2
> >technologies at the same height. 40' is pretty low for that antenna. Any
> >advice for a new Ham?
>
> The first fundamental thing you should do is to look at your terrain vs the
> potential height of your antenna, using a program like YTAD (free with the
> ARRL Antenna Book. your 40' may be the equivalent of 70-80 feet in a QTH
> with a flat or upward-sloping foreground. Incidentally, the effects of
> height are NOT dependent on the manufactrer of the triband yagi or
> equivalent that you choose, but on the frequency, the geometry of ray
> propagation and the characteristics of the ionosphere. A small antenna
> like the hex-beam will have approximately the same elevation pattern as a
> KT-36XA, but with less gain and front-to-back ratio.
>
> The choice of a tribander is a fairly straight-up tradeoff between cost and
> performance. A 36-foot boom antenna like the KT-36XA will require a
> stronger rotator and perhaps a beefier tower than a smaller one. Cost of
> the antenna itself is also a factor. If it were me, I would look seriously
> at a more conventional trapless antenna, such as the Force 12 C-3E, before
> investing in the hexbeam. The new XR-5 from Force 12 (www.force12inc.com)
> extends the same technology to providing gain and pattern on all 5 bands
> 20-10 on a short boom, but I don't know what the price is.
>
>
> 73, Pete N4ZR
>
> Sometimes a tower is
> just a tower
>
> ________________________________________________________________________
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