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.