At 02:53 PM 10/12/02 -0400, Guy Olinger, K2AV wrote:
>If
>the centers were 70-100 feet, it WOULD play like a 2 element shorty
>forty.
>
>A bit of apples vs. oranges here.
I still don't think it would be close, at least so far as forward gain is
concerned. I have a 4-element lazy-vee parasitic array, and have modeled
the array fed as a 4-square. ~6 dBi is the best you can expect, at the
nose of the main lobe, maybe 25 degrees elevation. By contrast, a
2-element yagi has ~5.5 dBi gain in free space, and benefits from up to 6
dB of additional ground reflection gain. At 70 feet, this means 10.6 dBi
gain at 28 degrees, and only a tenth or two less at 25 degrees. Even if
you look further down the "underside" of the first lobe, say at 15 degrees,
the gain of the 2-element yagi is still over 9 dBi, versus maybe 5 dBi for
the 4-square.
Which is not to undermine KQ2M's points -- instant direction-change is
terribly useful, and the better F/B and F/S of the 4-square will often let
you hear better.
73, Pete N4ZR
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