Need more gain than a single antenna can provide? Factory supported stacking options for the Dominator NWE-34 are now available. Email us for site specific details.
antenna is perhaps the least understood of all FM broadcast antennas. Some have
suggested it's just a J-Pole and that the bottom section does not radiate. Some
argue the cone is a non radiating transmission line to feed the top section.
Others mistake it as a 3/4 wave ground plane that would allow the bottom 1/4
wave of the main vertical section to radiate in a deconstructive phase and
create a peak gain about 45 degrees above the horizon. None of these theories
correctly describe the manner in which this antenna functions.
coaxial cone serves several important functions. In some ways is does mimic a
transmission line with it's ability to confine or shield radiation from the base
of the center vertical radiator. Because it's tapered, it transforms the
impedance of the antenna so that it can be efficiently matched to 50 ohm coax.
The cone is also tuned to act as an effective counterpoise and has both
transmission mode and antenna mode currents flowing through it. Transmission
mode currents are confined within the cone and antenna mode currents are allowed
to radiate constructively on the outside of the cone.
examine how this principle allows us to simulate a collinear antenna. Normally
the end fed antenna will begin to will begin to radiate from its base in a phase
that is deconstructive once the wavelength is increased significantly beyond 1/2
wave. Pass this point and the peak gain begins to shift in favor of an upper 45
degree lobe where it is wasted. This is why it is essential to confine the
radiation from the lower 1/4 wave section of the center vertical element.
Allowing the longer top section above the cone to radiate constructively with
the currents on the outside of the cone.
is displayed with color intensity and referenced to the chart on the right. This
chart shows the magnitude in amps per meter for the corresponding colors. Phase
is also indicated by opposing colors at the positive top and negative bottom of
the chart. The Dominator has obvious characteristics not typically found in
antennas other then collinear types. It has 3 separate radiation currents with
two allowed to radiate freely in a phase that is constructively combined in the
far field. The third current is in a deconstructive phase with respect to the
other two and has been confined within the tapered coaxial skeleton cone.
It is the tapered 1/4 wave coaxial cone that sets this antenna apart from others. It allows the longer top section of the main radiator to radiate freely while the deconstructively phased radiation on the lower 1/4 wave of the main radiator is confined within the cone. Since the base of the cone and the base of the main radiator are excited by opposite phase polarities, the currents allowed to radiate on the outside of the shielding cone combine constructively with the longer main radiator extending above the cone. Total currents radiated by the cone are divided into its four vertically tapered radials. This provides noticeable gain over a dipole on the distant horizon.
the Cartesian radiation elevation charts.
half wave dipole shown in red has a broader less compressed slope then the
Dominator shown in blue. This wastes power by radiating it well above and below
the horizontal plane. The dipole is still radiating 50% of it's maximum field at
an angle that is -60 degrees from horizontal. In comparison, the Dominator field
is reduced to 50% at an angle of -47 degrees from horizontal and it's down to
33% at -60 degrees. Effectively refocusing the power wasted at undesired angles
into a tighter beamwidth that is 3 db stronger then a dipole at the critical 0
degree elevation angle.
Because the Normalized fields are relative to the specific antennas full power field, it is not apparent how the beamwidth effects the two antennas Effective Radiated Power in comparison to each other. We only see the percentage of the individual antennas full field at any given angle. If we were to lay the dipole chart over the Dominator chart and used the Dominators Normalized Field as the reference point for peak field power, the differences would be clear.
peak field for the dipole would only reach approximately 0.75 or 75% of the
Dominators peak Normalized field. Placing it 3 db lower as a result of wasted
energy at angles that are not useful to VHF broadcast propagation. The
Dominators compressed beamwidth not only increases gain, it reduces on site RF
exposure levels with limited downward radiation making it easier to comply with
The Dominator antenna was developed for FM Broadcast in 1996 by Norwalk Electronics. It is a high gain vertically polarized .82 wave Coaxial antenna. It is the coaxial cone at the base of this antenna that allows us to go beyond the standard 1/2 wave and 5/8 wave designs while forcing the angle of radiation down on the horizon. The Dominator has the same vertical gain as four stacked circular polarized bays fed in phase and mounted over a forty foot section of tower.
This antenna uses a highly efficient Teflon insulated gamma match that eliminates any coils or matching transformers. That enables shunt feeding of the .82 wave main radiator, keeping it DC grounded for added lightning protection. This also gives the antenna it's ability to handle high power levels. The standard model is available with a gold pin Teflon insulated weatherproof N or SO-239 connector recommended for up to 1 KW input. Higher power versions are also available such as our 3 kilowatt using a Teflon 7/16" DIN connector and heavy duty gamma match.
Beware of poorly constructed clones that look similar to the Dominator. One distributor in Slovenia is selling an antenna that has been made to look like the factory authorized product . Clones are not factory authorized, are not shipped with assembly or tuning instructions and are responsible for many transmitter failures. Please visit our "Dominator vs. Clone" page for more information. Norwalk Electronics guarantees no single other FM broadcast antenna can produce a stronger signal or you can return the antenna to us within 30 days for a refund.
The Dominator is professionally manufactured using high grade 6063 magnesium alloy aluminum tubing. This antenna is currently in use by hundreds of stations around the globe from Alaska to South America. It has proved itself to withstand severe weather while providing a strong reliable signal.
The Dominator also offers unique possibilities
for use in emergency or temporary situations where an effective, easy to install
antenna is required. Be prepared for the unexpected as changes in weather
patterns can cause a severe weather system to strike at anytime. This has forced
some stations into the awkward position of having to reach their listeners after
the loss of the transmitter antenna and or tower.
The portable transmitter system below is owned by the CBC and operates the 3 KW Dominator antenna. The CBC uses this equipment for various applications including tower maintenance, emergency, and temporary use. The trailer can be brought to any site and set up in minuets with its onboard generator. Various audio feeds are available including satellite. The empty space in the rack fits a larger RF amplifier when required.
Pricing and specifications subject to change without notice.