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[TowerTalk] V-beam Report

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Subject: [TowerTalk] V-beam Report
From: (Jim Reid)
Date: Sun, 16 Nov 1997 14:25:10 -1000
To those interested,

Well,  they are up,  at least as they will be for awhile.
I am satisfied that the four are operating.  But the angles
between wires could be wider,  and more even;  I wish that
I could get the far ends higher.  Only way seems to be
helium filled,  string guided balloon to float the wires
up higher among the trees,  if that were possible.  Anyway,
will be a later project to look into.  Also,  since they are
not evenly spaced every 45 degrees,  I do not have the total
azimuth coverage I had planned for; nor,  in fact,  do the
main lobes of the V's direct to the azimuths I desired.  But
did what I could with the available trees and terrain layout.

So,  how do they work?  To the US mainland,  on 30 meters,  at
least 6 dB better than my 30 meter inverted V.  Because,  signals
which I can hear on the V-beam, which are audible,  but do not
move the S-meter,  and can also be heard on the inverted-V,
when the rf gain front end stage of the FT-1000 is turned off
(NOR switched to IPO) plus use of the front attenuator,  I can
always find one setting where the signal is workable on the V-beam,
but cannot be heard on the inverted-V without backing off 6 dB 
of attenuation.  If I can find a weak signal tuning with the
inverted V,  then switch in 6 dB of loss(assuming the Yaesu
attenuator is reasonably accurate) the signal is lost; switch
immediately to the V-beam,  and there is a clear,  workable
signal again,  even with the attenuation.  So,  that
is how I come up with the idea of a 6,  or so,  dB advantage
on 30 meters.

BTW, K6STI's AO models about 8 dBi for the V-beams on 30 meters
in the direction of the mainland.

On 40 meters,  I have not yet taken the time to perform similar
comparison tests,  but will in these coming evenings/mornings.
Have heard 9N1FP and Russian/JA stations on 40 with the V-beams;
the 9N1 did not respond to my call;  went QRT unfortunately!!
No West Eu station signals yet heard by me on 40 with either antenna
set up.  But I just have not taken the time yet to really do
a diligent search across the CW band.

On 75 meters last night I tried working some of the mainland
stations in the SS using the V-beams.  I do not now have up
an 80 meter dipole of any sort,  unfortunately.  However,
I had no trouble at all hearing many 75 meter SSB SS 
contest stations.  Unfortunately,  not many could hear me!!  
I actually worked  only a couple mainland stations: K6HNZ was 
one,  tried to get W3GH, NE3F, K9BGL  and K7VS to hear me among 
others across the country,  but my 1kW output just didn't 
capture their attention.  So that disappoints me;  I would
think that stations which I can hear just fine with these
V-beams ought to be able to hear me just fine when transmitting
with them.  But perhaps there were plenty of other nearby
mainland stations,  as they were all seeming to work plenty
of them at the time--0500 to 0600 UTC or so.

So that is the status to now.

73,  Jim, KH7M
On the Garden Island of Kauai

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