Hi Tod,
I would put the 40M beam on top (80 ft). 40M antennas play
VERY WELL at 80 to 100 ft. My experience with several
High Band beams is that 80 to 100 ft sucks during the day
when lower antennas are usually better to EU and AF.
High band antennas above 80 ft are good for opening /
closing the bands or in summer when MUF's rarely exceed
25 MHz.
FWIW, I like 110 to 120 ft for HIGH high band antennas
since the second lobe is in the middle of the useful high
angle range. At 80 to 100 ft, the second lobe is usually
above the range supported by the ionosphere and is
therefore a useless loss of radiation with a NULL in the
useful range of angles supported by the ionosphere.
Before installing the 402CD, I would double wall the first
section of each element, reinforce the boom ends and center
(dowel or tubing), and replace the non-stainless steel screws
in the coil assemblies with SS bolts and locking nuts (or
lock tight).
de Tom N4KG
On Sun, 8 Jul 2001 "Tod Olson" <tao@skypoint.com> writes:
>
> I suspect that I could get this answer from a diligent search of the
TT
> archives, but it is much more fun to get current thinking and
> experience.
>
> I am planning to install a 40 meter beam (40-2CD) on the same tower
> and mast
> as my triband beam (TH7). Should I place the 40 meter beam over the
> triband
> beam or the other way around. Assume that there will be at least 8
> feet of
> separation between the two antennas and that the lowest antenna will
> be no
> higher than 72 feet above ground. The antennas will be on a
> telescoping
> tower so the height above ground is another variable (between 32
> feet and 72
> feet for the lowest antenna).
>
> I have had a suggestion that I turn the booms so that they are 90
> degrees to
> each other. I can see that will introduce some interesting wind
> forces on
> the tower and the rotator. Anyone have an opinion (or even some
> experience)
> with this concept?
>
> Tod, KØTO
>
>
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