Andrew:
If you want to get the most from your qth , here some
ideas:
I will go for the TH7 from Hy gain, that will survive
most of your Bad weather, the F12 options requiere a
lot of reinforcement or a lot of maintenance during
the years and maybe some pipes, those rivets will
loose in constant high winds.
for your 40 meters needs , a forty shorty can works or
the same hygain 7-2 with redundant connections at
the ends to prevent breakage in the loading.
also you can load for the 80m and 160m your tower with
this antennas and some tricks
40m can work also with phased verticals in your back
yard, I read in the NCJ a guy using cushcraft new
40/80m verticals phased with a special phasing device
from Array solutions works FB for him in his small lot
good Luck in your proyect
--- Andrew Roos <Andrew.Roos@poynting.co.za> wrote:
> Hi All
>
> I've been licensed for 5 years now and have done a
> fair amount of
> operating, especially contesting, but only with wire
> antennas. I've
> finally bought a new house where I can put up a
> tower and beam. I've
> read as much as I can on eham.net and the
> manufacturer's site, as well
> as the Towertalk archives, but I'm wanting to
> canvass as much advice as
> possible as this is probably the only opportunity
> I'll ever have to
> build my antenna system from scratch.
>
> My primary requirement is to build the best possible
> contest station
> that my 13,000 sq. foot suburban lot, XYL and
> limited budget will allow.
> Due to budget limitations, I may have to build it
> over several years.
>
> I'm planning a 15m tower, probably self-supporting
> (unguyed). The height
> limit is because towers taller than 15m require an
> Environmental Impact
> Assessment process, which could be costly and which
> effectively gives
> any nearby neighbour the right to veto the project.
> So to keep it
> simple, I'll stick to 15m, then I only require
> building plan approval,
> but no EIA.
>
> I'm planning to start with a tribander, and stack a
> 2 element 40m beam
> in a year or two. The two tribanders that I'm mostly
> considering are the
> F12 C-19XR and the Bencher Skyhawk. It seems to me
> that the Skyhawk
> probably has the performance edge, and is possibly
> more sturdily
> constructed. The C-19XR has the benefit of reduced
> weight, which means I
> can still stack a 2 el 40m Yagi and stay more or
> less within the limits
> of a Yaesu G-1000DXC rotator (the 240 V version of
> the G-1000DXA).
> Although I can turn the Skyhawk by itself with the
> G-1000DXC, I would
> need a G-2800DXC or similar to stack the 40m beam.
> The other advantage
> of the C-19XR is that I believe one can use 3
> feedlines with it,
> allowing single-operator-two-radio or
> multi-op-two-radio contesting with
> the appropriate antenna switches and filters.
>
> The other option would be a single 4-band beam. The
> F12 C-39XRN is just
> too big for my small lot, so that leaves something
> like the C-4SXLD.
> essentially this would involve some compromise in
> gain on 20/15/10 in
> exchange for gain on 40.
>
> One thing to consider is that, living in South
> Africa, spares are
> difficult to get and may take weeks or months to
> arrive, so a sturdy
> installation is important. Regarding weather, we
> don't generally have
> snow or icing problems. However in the summer
> (November-February, which
> coincides with many important contests) we get
> tropical thunderstorms
> that often have hail and winds gusts of around 50
> kts (60 mph) are not
> uncommon. I don't know what the maximum windspeeds
> recorded are, but
> would like to exceed the fairly common 60 mph gusts
> by 50%, for a
> planned wind speed survivability of 90 mph (hence
> the "D" rating on the
> C-4SXLD). Lightning protection is also important, as
> Johannesburg has
> one of the highest incidences of lightning strikes
> of any city in the
> world - again during the November-Feb contest season
> :)
>
> Sorry for the long post. Any advice, comments or
> suggestions will be
> greatly appreciated!
>
> 73
> Andrew ZS6AAA
>
>
> _______________________________________________
>
>
>
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>
Hector Garcia XE2K / XF1K
Mexicali B.C DM22fp
http://www.dxxe.org
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