ORIGINAL MESSAGE: (may be snipped)
On 6/20/2014 5:17 AM, Herbert Schoenbohm wrote:
Why not many serious DX-ers and contesters consider Tri-band or even
Five-band quads is a mystery to me.
REPLY:
I can perhaps explain it from my own experience. A quad large enough for
20 meters is a mechanical nightmare. Unlike a yagi, a quad is a three
dimensional object and that makes all the difference. I put up a four
element Cubex three band quad years ago and will NEVER do it again. The
quad works very well once you get it up in the air, but getting it up
there is a real hassle.
It's true that a two element quad is about equal to a yagi of three
elements, but adding a third element to a yagi is child's play compared
to the hassles of a quad.
I am presently running a CushCraft X7 which is a very clever design,
IMO. Been up for years with no troubles. It has traps, but NOT in the
driven element(s), which avoids most trap problems. The driven element
is actually a four element log-periodic which gives great SWR bandwidth,
and the rest of the antenna is a conventional yagi. As a bonus, it works
(with lower gain) on 17 and 12 meters, with a somewhat higher SWR. I do
restrict the power on 17 and 12 to 100 watts just to be safe, but it
works much better than a dipole for those bands, at no extra cost.
By the way, the balun on the X7 is extremely low loss. As a test, while
it was on sawhorses, I ran 1500 watts steady carrier for ten minutes
through it on the three bands. The heating in the balun was barely
noticeable, no more than 1 or 2 watts by my estimate. Pretty impressive.
73, Bill W6WRT
dezrat@outlook.com
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