At 09:04 AM 7/14/2005, Keith Dutson wrote:
>John W0UN wrote:
> >Solid dielectric is much more controllable, but I even measure the actual
>phase shift for each delay line of solid dielectric coax, if the application
>is critical.
>
>For HF, the delay is likely not critical. From reading the ARRL Antenna
>Book I understand phase errors up to 30 degrees for antenna phasing have
>small effects on radiation pattern and TOA.
>
>73, Keith NM5G
This was best demonstrated by OH8OS in his paper about phasing his
2 x 3 array of 6L 20M KLMs -- 2 wide by 3 high, for a total of 36 elements on
20M. He had the capability of rapidly phasing the array to match the
angle of the incoming signal, but found that the advantages were minimal
and not worth the trouble as long as you could go from in-phase to out-of-phase
to move signals from the elevation angle nulls to the peaks.
With my 4-stack of 8L 10M beams I had a total of four elevation angles (info
presented at Dayton in the early 1990s) but found that on anything outside of
the US (from Colorado) it was almost always best with all four
antennas in phase.
But then 10M is a low-angle band. This may not be true on, say, 20M or 40M.
--John W0UN
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