> My plans are to put one at the top of my 110 foot rotation tower (see
> http://www.w2fla.com) . With the property at over 2000 feet above sea
They make terrible lightning rods, and the precipitation static on
almost any top mounted antenna will kill the receiver during storms.
My personal selection, after much thought, was a DB224E four-dipole
array. It has nearly the same gain, but will take lightning hit after
lightning hit without problems.
For precipitation static, I'm side mounting a cheap MFJ 17-foot long
dual band fiberglass antenna. It has just slightly less gain on two
meters than the Station Master or 4-dipole array, but only costs a
hundred bucks. I'll switch to it during bad weather, and use it on
70cm during other times.
> level on top of this mountain, it should work gang busters. I am also
Maybe, but height AMSL doesn't mean squat for anything except working
ships at sea. I have huge problems convincing people the best spots
are not always "the highest spot between here and Florida". I have a
friend who has a terrible VHF/UHF radio location because he has high
surrounding ridges in the distance, and big power lines that wipe out
HF reception. But the exceptionally poor site does look OK as far as
AMSL height goes.
The proper parameter is HAAT, with obstructions on the path
considered. One huge problem with mountains is they usually have
other mountains around, and by themselves are pretty "fat". Those
effects can cause big dead spots despite high ASL. Antennas also can
lose a few dB because of lack of downtilt in pattern, so you might
want to look at that.
Just be sure the mountain itself does not shield the path to desired
stations, or even get close to doing that! Even if the path slightly
clears the earth you can get big time nulls caused by scattering that
are not correctable just by adding downtilt.
> going two install (2) Cubex 8 element 2 meter quads (vertically
> stacked) at the 80-90 foot mark for pin point communications. Of
I'd stack something with a more useful gain pattern, like yagis.
Quads are really just two 1/2 length element yagis stacked 1/4 wl
apart. When you stack quads, they actually work worse than the same
stacking distance when stacking yagis.
As a matter of fact, a small gain advantage of quads over a similar
spaced yagi only applies to one, two, or three element quads in
freespace. That advantage totally disappears with longer arrays, or
if you stack the antenna in the H plane of each antenna.
If you are serious about having a good signal, I'd rethink the system
a bit and look closer before doing anything.73, Tom W8JI
W8JI@contesting.com
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