
Below are shown some of the basic building
blocks
of the Moxons
3/8" thick x 24" long blank element
mounting platforms
Please Note: Plots were generated
with an elevation angle of only 10 degrees, raising elevation
angle will show gain of over 11 dbi
but azimuth pattern stays pretty much the same. Notice the clean
elevation pattern and low take off angle. Keep this in mind when
comparing to other antennas, in other words be sure all the parameters
are same.
Above plots show 20 meter moxon at a height of 36 feet which is
approx. a half wave length. Patterns will vary away from the design
frequency. However a Moxon has very good bandwidth and we designed
our antennas at some point between the upper and lower end of
each band so good SWR, gain and front to back will exist over
the whole band. For best performanc the moxon should be mounted
at 1/2 wavelength above ground but another very desirable characteristic
of this antenna is it will still maintain good patterns at a lower
height. For example the 20 meter unit can be mounted as low as
20 feet and still have good gain and front to back ratio.
Gulf Alpha Moxons are constructed with solid aluminum rod and
machined couplers. We feel the use of solid rod is better than
tubing, if a solid rod is bent from a fall, just bend it straight,
with tubing this is usually not possible without breakage.
How does a MOXON differ from a Hex Beam?
The Moxon has broader band width and higher forward gain and front
to back ratio than either the classic or modified hex beam. One
advantage of a hex beam-it can easily be multibanded, the moxon
is pretty much a single band antenna.
About the Black Clamps securing the radiating elements-These
clamps are made of Acetal (Delrin) which is an engineering thermoplastic
with great properties across the spectrum. Do not confuse this
with commodity grade plastics such as resin, PVC and others. Acetal
is used in many applications to replace metals. Although our Acetal
clamps look similiar in color to the inexpensive resin blocks
sold by some vendors there is a world of difference. We purchase
this material in sheet form and cut and machine to our own specs.
in our shop. This allows us to make the clamp the size and dimensions
we need for the particular application. Acetal is expensive for
example the 2" thick can cost from $130.00 to $160.00 per
square foot. Some of the properties shown for Acetal by some of
the many industrial plastic distributors:
# Excellent tensile strength.
# Good impact strength.
# Low friction.
# Low moisture absorption.
# Good electrical insulator.
# For indoor and outdoor use.
# Machines easily.
# Opaque black.
# Temperature range: -40° to +185° F.
# Melting point: 347° F.
# Meets ASTM D-6100.
# Black color aids in maintaining a consistent appearance after
being machined or exposed to light.
Acetal is a highly crystalline material and is therefore is an opaque white color in its natural state. Acetal is available as a homopolymer or copolymer, although both classes provide excellent mechanical, chemical, and electrical properties. They are able to do so over a wide temperature range and over long periods of time. Unlike nylon, acetal is not hygroscopic and will not change dimensionally in a humid environment. They also provide superior creep and fatigue resistance. Acetal is well known for its friction and wear properties and is one of the strongest and stiffest plastics out there. Additives can be used to increase these and other properties even more so. Acetal requires protection from UV by using additives, such as carbon black, in order to keep it from degrading with prolonged exposure. You will find acetal in many plumbing applications, such as impellers, pumps, showerheads, nozzles etc., typically where water exposure is high. They are also common in industrial and electrical applications for things such as gears, cams, switches, buttons, and handles. Spiratex has experience extruding profiles, filled and unfilled, for various industries.
MOXON ANTENNA MODELS
40 Meter -
51' x 18.5' length x width
30 Meter-
36' x 13'
20 Meter -
25' x 9' -$389.00 plus shipping-antenna
weight 36 lbs.
17 Meter-20'
x7' -$369.00 plus shipping-antenna
weight 30 lbs.
15 Meter-17'
x 6'
12 Meter-14'
x 5.5'
10 Meter-13'
x 5' -$219.00 plus shipping
6 Meter-7'
x 2' 7" -$169.00 plus shipping