Hi Mike!
For the record, K3LR on 15 meters has been upgraded!
This past summer we changed out the 3 high stack of 6 element Yagis.
The new K3LR 15 meter antenna system is a 4 high stack of 7 element OWA Yagis =
28
elements.
At 160'/120'/80'/40'. The over ground gain of this array is greater than 20 dBi.
I built a custom antenna switch for this array that allows 10 combinations of
antennas to be fed.
The new antennas work very well! The 15 meter operators have never commented
that
they thought they were too "sharp", however the F/S and F/B of the new array is
amazing!
Pictures are on http://www.k3lr.com
73!
Tim K3LR
Michael Keane K1MK wrote:
> At 09:21 AM 2/24/07, Bill Tippett wrote:
> >K1TTT wrote:
> > >With 5 or 6 elements from here you can not
> >cover all of Europe without rotating them.
> >
> > I strongly disagree. My 6 element KLM array
> >has a 3 dB beamwidth of about 54 degrees, which
> >is plenty for Europe.
>
> The original comment was in the context of using fixed direction
> Yagis in a stack.
>
> >K3LR, K9NS and W3LPL use even longer booms with even narrower
> >beamwidths, and they
> >seem to do well.
>
> AFIK, W3LPL's 15m stack of 6/6/6 is on a rotating tower and the
> antennas in K3LR's 6/6/6 15m stack are independently rotatable on
> rings. K9NS is another skip zone further from Europe which figures in as well.
>
> As always in these comparisons, the # elements is probably the worst
> parameter for comparison. Beamwidth goes as gain which goes at boom
> length; # elements enters in as a secondary dependence, less for OWA
> and LP driven element designs.
>
> Nevertheless, the difference between the specified E-plane beamwidth
> of an M2 15M4DX (4-el on a 27' boom) and a 15M6 (6-el on a 45' boom)
> is just 3 degrees ( 51 vs. 48).
>
> 73,
> Mike K1MK
>
> Michael Keane K1MK
> k1mk@alum.mit.edu
>
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