Put up LOTS of towers !
EVERYBODY needs a good multibander that rotates at 40 ft.
The HyGain TH11 or Force 12 5BA are good candidates.
A F12 C31XR plus WARC beam is another good option.
Another multibander at 110 to 120 ft is an excellent choice for
low angles plus the second lobe at that height is in the useful
range of higher angles still supported by the ionosphere.
(Second lobe angles on the high bands for 80 to 100 ft
high antennas are TOO HIGH to be supported by the ionosphere).
Use Philystran or Fiberglass Rod non-conductive guys
with steel cable at the ground level (for 27 ft) to prevent
damage from fire or vandalism.
80 to 100 ft works well on 40, 30, 20 M at NIGHT
My 80 ft high antennas SUCK on 10 / 15 during daylight hours.
The CC XM240 is an excellent 2L 'shorty forty'.
Fixed 2L40M Delta Loops suspended from 20 ft
booms or rope supports at 120 ft are KILLER antennas.
80M dipoles play very well at 140 to 160 ft.
I wish I had extended my 130 ft towers to 160 ft. to
accomodate sag in the middle. Stacked 2L40's
play very well at 80 / 160 ft.
For serious contesting, a set of single band stacks
for 10, 15, 20 is the next step. 2 high stacks on
Rohn 25 towers of 60, 70, and 90 ft for 10, 15, 20
is a cost effective improvement over tribanders.
With 12 acres, you have plenty of room for 580 ft Beverages
at 30, 45, 60, 90, 150, 240, 270, 330 degrees.
Above height recommendations *assume* flat land.
If your terrain is uneven, you need to look at a
Terrain Analysis program to get the desired angles
taking slopes into account.
This is MY idea of "doing it right the first time".
Tom N4KG ( with 7 towers on 4 acres )
On Tue, 19 Mar 2002 20:46:37 -0600 "Tom Branch" <tom@k4nr.org> writes:
> Greetings,
>
> After a couple year break in the action I'm finally putting an
> antenna farm back together. I purchased 12 acres so I have
> lots of room and the nearest neighbor is 800 feet away!
>
> I have a 80-foot Height tower that will initially be center of the
> main antenna. I plan on safety guying at the 40 and 80 foot
> levels--the West Texas winds can get up there! I'd like to use
> the upper set of guys as triangular array of dipoles on 40 meters.
> This seems reasonable enough by breaking up the guy wires
> leaving a 40 meter dipole in each guy. Feed each guy with
> a 3/8 wavelength coax and use DPST relays to switch it around.
> From West Texas I would think that orienting the array with one guy
> at 60 degrees, one at 180 degrees and the last at 300 degrees would
give
> reasonable coverage. I'm considering using Phillstran on the lower
> set of guys and on the ends of the upper guys.
>
> I'm also considering using elevated radials (3) at the 10-foot level
> for 80 meters. A simple loading coil at the feedpoint would allow for
> selecting between 75 and 80 meters.
>
> A couple of questions.
>
> How far should the guy points be from the base of the tower?
>
> Any pros or cons to using Phillystran as described or would it be
> cheaper to just use the small guy cable and break it up with
insulators?
>
> If insulators, someone suggested using 19 feet as the distance
> between insulators--suggestions?
>
> Will the 40 meter array interact when using 80/75 meters?
>
> I want to do this right the first time around, so please feel free
> to make any suggestions...
>
> 73 de Tom
>
> tom@k4nr.org
> http://www.k4nr.org
>
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