[CQ-Contest] 4O3A Station rebuild

[cqtestk4xs at aol.com]

I have three Optibeam 16-3 tribanders.  Although my location is quite a bit different with huge dropoffs the concept is the same.  I have a 94 foot tower but three Yaigs were used so the station would rock on 15 and 10.  With the antennas spaced around 31 feet or so, I don't know how useful the middle Yagi is on 20, since it is less than 1/2 wavelength. However, the single top antenna is always weaker than the stack.  


On 15 it's a different story, with the spacing in the "sweet area" around 2/3 wavelength, while the spacing for 10 meters is a little under one wavelength, still in the sweet zone.


Stacking tribanders is always a compromise.  Out here, and county limited to a single tower, I had no choice.  Ideally, it should only take two tribanders for 20, so the middle one at my place probably is not doing doing it fair share, but I can tell you it certainly works on 10 and 15.


By the way I had three big rotating towers at my old place.  One tower had 4-20 stack...5/5/5/5  and 4-10 stack....7/7/7/7, the 2nd had 40 stack...4/4  and a triband stack....3 KT36XAs, the third had only the 15 stack....6/6/6/6.  I was able to operate SO2R assisted with no filters needed.  I highly recommend that set up with three towers.


Bill KH7XS/K4XS



-----Original Message-----
From: Ed Sawyer <sawyered at earthlink.net>
To: cq-contest <cq-contest at contesting.com>
Sent: Fri, Apr 20, 2018 8:23 pm
Subject: Re: [CQ-Contest] 4O3A Station rebuild

Ranko.  I am surprised that phased towers with tribanders would be the
desired position if 40 and 20 are the focus.  The mono optimization for 20M
is rarely best done with tribanders. It's a great system when a single tower
is used for all bands although many times I have seen people add an extra
monobander or 2 on 15 or 10M because of the stacking compromise.

 

Also, the beam width becomes much narrower with horizontal stacking
(phasing).  Is that really the goal for contesting?

 

I would think that an optimized array on 20M would be one tower.  An
optimized array on 40M would be the other tower,  And a few monobanders for
15 and 10M would be the fill in for the low sunspot years.  Possibly in
different directions than the optimized arrays on 20 and 40 to best utilize
the band mix.

 

73

 

Ed  N1UR

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