Right Antenna?

Is The NWE-34 The Best FM Broadcast Antenna For Your Application?

You’re here for one reason, to investigate if this FM Broadcast Antenna would be an asset to your station. It’s our responsibility to assist you with information on how to choose the best antenna and to stand behind any potential sales with our money back satisfaction guarantee. No one antenna is the best choice for every station. Some government’s regulations may even prevent the use of the “best antenna” in certain cases. The first things to consider are license requirements, station budget and available space to mount antennas.

Since the Dominator NWE-34 FM Broadcast Antenna concentrates all of its radiation currents in the vertical polarization, you must first check to insure your license does not require equal horizontal component be present. The USA is exclusively behind the times in this area because we developed the FM band before radios were portable or placed in vehicles where horizontal coverage is extremely limited beyond the local range. This is due to the fact that nearly all horizontal antennas exhibit noticeable directional characteristics. Making them unsuitable for use in mobile applications or where reception of multiple stations from different directions is desired.

Today, there are virtually no FM stations that transmit a horizontal only signal since the use of horizontal or outdoor directional antennas for reception is very rare. The FCC has since required that most FM stations in the USA still retain compatibility with older horizontal receiving antennas by sending a horizontal signal with the option of mixed or circular polarization using an equal balance between both vertical and horizontal. In the USA, Translators, LPFM, Boosters, non commercial and Auxiliary / Backup stations are exempt from the requirements of horizontal component and are allowed by the FCC to benefit from the efficiency of linear vertical polarization. Additional exceptions are made for FM stations operating in the low end of the band who’s coverage area overlaps that of a VHF TV CH.6 transmitter.

Stations dealing with RF interference in studio or audio equipment (often identified as a constant hum) and those having to minimize hazardous RF exposure levels around the transmitter site will realize the NWE-34 has additional benefits in these areas. When compared to typical circular polarized antennas, the Dominator NWE-34 has significantly less downward radiation. This allows a relatively small amount of vertical separation between the antenna and ground (or audio equipment) to eliminate RF interference and comply with new safety regulations regarding RF exposure levels.

The choice between vertical or CP becomes clearer once you realize forming a CP signal requires that two sets of elements must be driven by the transmitter in opposing polarizations. This splits your transmitter power between the two polarizations and cuts the power gain of the antenna system and your Effective Radiated Power in half. Therefore CP requires twice the amount of transmitter power or double the amount of antenna bays stacked on the tower to reach equal signal strength of an array using unity gain vertical dipole antennas.

Keep in mind the Dominator NWE-34 FM broadcast antenna has two times the power gain of a vertical dipole and will double your ERP. One NWE-34 antenna at the top of the tower also provides the same power gain and Effective Radiated Power as four side mounted CP bays while achieving a perfect omni directional pattern. Stacking options for the NWE-34 are exclusively available with free technical support on this factory direct website.

You provide us with your site details ranging from location, tower specifications, frequency of operation, and required ERP and we will design a site-specific plan to meet your needs. From Low Power FM stations using a single antenna at 100 watts ERP to powerhouses operating at 50 kw ERP with 8 bays and a Transmitter Power Output of just over 3000 watts! The NWE-34 antennas are guaranteed to produce the most range per watt or your money back within 30 days. They are rugged too. If one should fail for any reason other than being dropped off the tower, we will repair or replace it free for 3 years.

Choosing the type of antenna used in FM broadcast is essential to the stations coverage and not a choice that should be taken lightly. It’s been over 20 years since Norwalk Electronics designed and tested the first Dominator NWE-34 FM broadcast antenna in 1996. It would not be unreasonable to assume we’ve developed some bias towards the antenna through the results of our clients over this time. The best advice comes from the experience of knowledgeable people with zero bias.

More weight should be placed on field test results conducted in cooperation with engineers hired by various world governments including the United Kingdom and Israel. If you are interested in learning about the advantages and disadvantages seen with different types of polarization used in FM broadcast antennas, you’re encouraged to read the Polarization Info page by clicking on this link: Polarization Info The information on that page is supported by this earlier BBC publication: http://downloads.bbc.co.uk/rd/pubs/reports/1986-13.pdf

Mr. Blank’s work in the first link is a quicker read than the BBC publication. Both independent studies recommend the use of vertical linear polarization in new installations because it offers the highest efficiency while matching the polarization of the vast majority of receiving antennas. Mixed polarization or CP was suggested in areas where interference was problematic. Not so much for any benefit in terms of multi-path reduction or better coverage and more for the directional characteristics of horizontal receiving antennas that could null out interference or an undesired signal from a different direction.

Consider that CP has additional expenses that may provide little return in applications where severe interference is not an issue or where non-directional receiving antennas are often used. Is the budget available to purchase a transmitter having four times the output power and electric consumption? Do you have the option or space to install four times as many CP antenna bays on the tower to reach the same ERP of one Dominator NWE-34? When the answer is no, we guarantee to provide the same range at a fraction of the cost.

If you’ve answered yes to either of the two questions in the above paragraph and your only limitation is your maximum licensed ERP rating, then CP is an option to consider as the FCC allows you to repeat the same ERP in both the vertical and horizontal plane. Since the NWE-34 is positive 3dB over a 1/2 wave dipole and the CP antennas are negative 3dB under a dipole, it comes down to determining if it’s worth four times the power or number of CP antennas to reach the small percentage of distant receivers that may be connected to a fixed horizontal antenna. For a partial list of station call signs using this antenna with FCC data and coverage maps, please visit our Home Page.