Craig
this is in no way a definitive answer , just my
experience/results. i worked my first ~ 150 or so
countries using a vertical, the next ~100 were with a
3 el tribander (13.5 ft boom) , the next ~50 using an
amp... the remaining ~30 were with my current config
7el multiband yagi at ~75 ft and 1500W. i had/have
(Ohio) a destinct geographical advantage over you guys
in Nevada for a great many areas so that may have
helped a bit too...
to me it wouldnt be worth the extra $3K , but , i
would definatly go with the 60ft over the 45 if i
could get it. at 60 ft you would have a little
disadvantage on 20m i think. But, the DX stations
these days have much better setups than they did back
in the early 80's during my reign of terror on the
bands, as well as the dxpeditions these days.
On the other hand though if you can swing the extra
$3K and get the zoning, it may be worht it to you
since you should have the tower for 20+ years so the
added investment isnt really all that much in the long
run...
now that was lots of help wasnt it ;-)
good luck
Dan N8DCJ
--- Craig Sande <craig.sande@sbcglobal.net> wrote:
> At this time I am only in the early stages of
> planning a tower installation at a new QTH. The
> local planning board has changed their tower
> ordinance, so I will need to request a variance
> (called administrative permit $883) for anything
> above 45 feet. The building department requires an
> engineers stamp to certify that the structure will
> meet the UBC with wind rating of 85 mph and exposure
> C.
>
> Most of the crank-up towers are advertised with 70
> mph ratings, but it is difficult for me to translate
> that to 85 mph, as I understand that the wind
> loading goes up exponentially. I would like to be
> able to handle about 15 sf of antenna on a
> self-supporting crank-up tower with 10 foot mast
> extended about 6 feet above the tower.
>
> With Tashjian Towers, for example, I can use their
> LM-354 HDSP which will get the yagi to 60 feet (54'
> tower plus mast). The only other option they would
> have would be the DX-86 with the top section
> removed, thereby bringing the tower down to 70 feet
> and the yagi to 76 feet. Using my calculations (not
> a formal bid), the higher tower would cost an
> additional $3000. (Their LM-470 wouldn't be able to
> handle a 15 sf load at 85 mph/exposure C).
>
> How much more effectiveness, in terms of working dx,
> can I expect in going from an antenna at 60 versus
> 76 feet? I've played around with EZNEC and can
> demonstrate a decrease take off angle, but the
> difference doesn't appear dramatic. Hmmm.... is it
> worth the extra money??
>
> Thanks for your thoughts,
>
> Craig, AE7I
> _______________________________________________
>
> 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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>
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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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