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[TowerTalk] V-beam proj. Quick Update

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Subject: [TowerTalk] V-beam proj. Quick Update
From: (Jim Reid)
Date: Tue, 15 Jul 1997 13:54:31 -1000
Aloha to all,

Thanks to the remnants of hurricane Dolores,  Kauai has been
cut off from the trade winds and showers these last couple
of days.  So this morning,  early,  we got the West most
rope out about as far as we could go.  Hurricane Enrique has
fallen apart well East of Hawaii,  and tropical storm Felicia
won't develop into a full hurricane for another day or 
two, and is still over 3100 miles SE of Kauai, should be no
problem out here for another week or so, if ever at all.

With the grass and "jungle" dry,  was a pleasure to work out
there,  except for the mosquitos! Random breeze was too weak
to keep the pesky things away.

Unfortunately,  we may have to cut the V-leg lengths back to around
450 feet or so,  down from the hoped for 600 feet.  Causes a loss
of around 2.8 dBi or so of gain (on 40),  and the beam widths increase 
some. Also the angle between wires may have to come down to 
about 39 degrees from 47 to 50 degrees.  These changes occurring because
of the lack of suitable terminating trees at more desirable distances,

Have been using Brian Beezley's, K6STI, AO program to check model what we
are up to.  I know,  it would be better to use NECWires,  but I
don't know how,  and just barely think I know what I am doing with
Brian's AO program.  It is all DOS(which intimidates me),  but to 
really get optimum answers the set up must be in "Symbolic dimensions 
and expressions".

Reading the AO.doc file did not help me much about this issue,
just plumb dumb!!

I did figure out how to express the end points of the V using simple
trig,  just multiply the leg length by the sin and cos of the
semi-angle between V wires.  Then enter in the model Brian provides.
But how to do that with symbolic expressions,  which can then optimize
the set up,  don't know;  as I say,  just my lack of smarts!

Anyway,  if the trades stay cut off for another day or so,  should
get up the East most wire supporting rope,  then the fun of pulling
the four beam wires across/along the ravine can begin!

73,  Jim,  KH7M

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