FACTS ABOUT GAIN

Gain is an important specification with many variables to take into consideration. Any qualified RF engineer (and the FCC) will tell you the standard for this measurement is referenced against the gain of a half wave dipole. Here is where it gets complicated with FM broadcast and typical multi bay antenna installations.

The dipole exhibits its best gain when mounted in an environment that is unobstructed by it's means of support. Such as the horizontal dipole supported by it's ends with insulators and fed through the correct matching network for impedance and matching to unbalanced coaxial cable. Under these circumstances, this is the standard for what is considered "unity gain" or 0 dbd.

Here is what none of the big manufacturers want to tell you. Lets say you take a four bay vertical dipole array for FM broadcast use at an LPFM station with a 100 foot tower. The manufacturer has told you the system has a gain of 6 dbd. In the real world there are many things affecting this ideal gain because of how the array must be spaced and side mounted on the tower, driven with RF through power dividers, and tuned to equal resonance in all bays.

With the grounded tower directly in line with the bays, this distorts the radiation pattern and effects gain. Some people know this and make the best of the situation by placing the bays on the side of the tower where the most coverage is desired. The tower effects the RF in at least three major ways.

1. 1. First the tower blocks some RF in the direction where the tower blocks the view of the antenna.

2. 2. It may also reflect some (but not all) of this energy back in the opposite direction of the tower.

3. 3. The tower can even absorb some RF energy because it is a non resonant, metallic object that is grounded.

This is where the tower differs from a resonant, parasitic element that would be an efficient reflector. Then there is VHF power divider. Two power dividers are used to drive four bays and they claim to have absolutely no loss with all of those connectors in the feed line, or at least nothing is mentioned of any. Don't forget your bottom bay is going to be 40 feet lower then the top of your tower. This is critical at the LPFM installation since that bottom bay is only able to make use of little more then half of your tower height. Lowering the entire center of radiation and signal penetration.

When compared to the half wave dipole standard, the Dominator has a true gain of 3 dbd or 5.15 dbi. This is a power gain of two times the applied RF. So if you have a 100 watt ERP you need to feed the antenna with 50 watts (not calculating coax loss). When compared to the four bays side mounted on the tower with a claimed gain of 6 dbd, a single Dominator at the top of the tower provides the same gain and coverage area as the four bays with a true omni directional radiation pattern.

This is unheard of in all other Commercial FM broadcast antennas due to their required side mounting. The Dominators unusually long .82 wavelength design emits an intense narrow beam of low angle radiation on the horizon. Combined with it's single radiation point being located at the top of the tower, gives it unmatched performance by any other antenna and why we claim it performs as effective as the 6 dbd four bay system.

Having conducted business through the web for several years we've had imitators (learn more) who make ridiculous claims about their product and in turn some uninformed patrons unknowingly believe these claims before testing our product. Additionally we've had customers write in to tell us after testing our product they've realized ours has superior performance and in most cases went beyond their expectations.

It's an entirely different matter to develop an antenna that performs up to the standards required to carry the guarantee we offer to our customers. We put our money where our mouth is and stand behind the Dominator antenna 100%. Within 30 days of receiving your Dominator antenna, if for any reason you find it was not as advertised or did not live up to the claims we make here, simply send it back for a refund of your purchase price!

Whether you're an LPFM operator needing a simple and powerful antenna or running a 50 KW class B planning ahead for the time an effective backup antenna will save the day, the Dominator will exceed most expectations.