The best of the wire type antennas is the rhombic antenna each side 4 of the rhombic antenna must be 1 or two wavelengths long. Which if ive done this correctly means a wavelength of 1. Exactly what i wanted to know, i may hold off on this one and search for a different type high gain uhf antenna. I have worked him before and his signal is not just a result of a rhombic antenna, he runs a lot of wattage and has a lot of background noise too. Rhombic antenna basics, radiation and designing in antenna. A rhombic antenna is made of four sections of wire suspended parallel to the ground in a diamond or rhombus shape.
A rhombic antenna is a type of antenna that covers a wider range of frequencies than most antennae. The book contains just experience and needed information. Directional tactical wire antenna, designed for longrange pointtopoint communications. Explain resonant and nonresonant modes of long wire antenna. Increased parallel resistor stages will increase overall input wattage. In this video, i have explained rhombic antenna by following outlines. Description and simulation of two types of rhombic antennas, using the software 4nec2. Look for my latest antenna article, the rhombic loop twofer, in the june 2017 issue of qst the rhombic loop twofer is two antennas in one a small but potent rhombic by day, and a loop skywave by night. A rhombic grid array antenna rgaa is proposed and its frequencyscanning performance is discussed. The antenna consists of a wire suspended above the ground in the shape of a rhombus, terminated at one end by a resistor equal the the wires characteristic impedance, about 400 to. Horizontal rhombic antennas are the most commonly used antennas for pointtopoint hf naval communications. A rhombic antenna is made of four sections of wire suspended parallel to the ground in a. It is usually used for high frequencies, which are also known as shortwave.
As i studied the arrl antenna handbook i learned about the various types of antennas. Diagram of radiation patterns of wire segments of a. We will look at a few rhombic antenna designs including an inverted v in the article below. It is arranged in the form of a rhombus or diamond shape and suspended. Some years ago i became interested in a special type of antenna. The leg lengths of the rhombic must be an integral number of half wavelengths. This link is listed in our web site directory since thursday oct 26 2006, and till today rhombic antennas has been followed for a total of 2815 times. May 02, 2018 in this video, i have explained rhombic antenna by following outlines. Rhombic tv antennas unlike the conventional type of tv an tennas which use aluminum tubing and other material that can only be made in a modern factory, this type of antenna uses ordinary copper wire, insulators and poles, and is put up in much the same manner as the ordinary outside radio antenna which has been built by. Pdf we present an analysis of mutual coupling effects on radiation pattern and. It is organized in the form of a rhombus or diamond shape and suspended horizontally. The rhombic antenna is often claimed to be an exceptionally good antenna with very high gain. This antenna consists of four long wires, positioned in a diamond shape. A typical rhombic antenna design would be at a height of between a half and a full wavelength.
There are 2 versions of the rhombic antenna, the resonant rhombic antenna and the terminated rhombic antenna. This kit of parts for a rhombic antenna should be assembled by an experienced ham, or technician. A practical guide to the design of rhombic aerials. The rgaa has numerous bent radiation elements, forming rhombic cells and loops. Bprh230 rhombic antennas have high directional gain and low takeoff angles and are best suited to long distance, point to point communications. The rhombic antenna is a highly directional array ideallysuited for medium to long haul circuits. Rather than tiptoe up to trying to get in stations with rotators and larger and larger deep fringe antennas i found the rhombic antenna. Rhombic antenna works under the principle of travelling wave radiator. All resistors are carbon 5w, creating 10w max dissipation per leg. Rhombic termination resistor termination resistor needs to be near 800. The sides of the rhombus each consist of two or more parallel conductors. I wanted to know if it really was as good as you hear in all the stories about them, and, if we could use them in our contest applications. Rhombic antenna dimensions and plan for hf and vhf bands by n6jsx.
About rhombic antennas the resource is currently listed in in a single category. The rhombic antenna is a broadband directional antenna. The directivity of a rhombic antenna can be reversed by interchanging the feeder and the terminal resistance. Radiation angles vary with the design and ground coefficient. Rhombic antennas, vbeam, and inverted v but, this was on 10 meters, not say 40. Rhombic antennas were the ultimate antenna design back in the golden age of wireless. It covers 174 mhz 192 mhz, centered around 168 mhz. Rhombic antenna mechanisms under the source of travelling wave radiator. The rhombic antenna is a directional wire antenna used on mf and hf bands for shortwave reception.
This kit of parts is not intended for novice antenna builders. Mutual coupling effects analysis in a crossrhombic antenna array. Design a rhombic antenna to operate at 20mhz when the angle of elevation angle 10o. Author, the antenna manual for fringe and bad ghost areas the rhombic antenna will always outperform an ordinary dipole array. The rhombic antenna is an equilateral parallelogram shaped antenna. I have not kept in touch the last decade but bill was a mentor to me. Rhombic antenna article about rhombic antenna by the free. The main category is rhombic antennas that is about rhombic antennas. If we assume othe average beamwidth of rhombic antenna as 10, then design an antenna system such that it will radiate maximum power over the. Pdf mutual coupling effects analysis in a crossrhombic. Rhombic antennas can be characterized as highpower, lowangle, highgain.
However, building one required a large tract of land and a lot of telephone poles, because they have dimensions several times the wavelength, and back then the wavelengths in use were tens of meters and longer. I couldnt get excited by dipoles, loops, yagies, or quads because i wanted one antenna that would cover many bands and produce a strong signal. The rhombics low cost, simplicity, reliability, and ease of construction sometimes outweighs performance. Rhombic antennas suited to operation down as low as 2 mhz are large. The most common use of a rhombic antenna is in amateur radio relay and broadcasting. If we look at this link to this pdf document on rhombic design we find suggested dimensions for rhombic antennas. Such a double antenna consists of two rhombuses that are displaced with respect to each other by 0. Each of the four sides is the same length about a quarterwavelength to one wavelength per section converging but not touching at an angle of about 42 at the fed end and at the far end. The antenna is placed end to end and terminated by a noninductive resistor to produce a unidirectional pattern.
The cross rhombic antenna cra belongs to the family of traveling wave antennas, with circular polarization, medium gain, and a directional eld pattern. The main feeder and the dissipation line are also centered at this point. Electronics technician volume 7 antennas and wave propagation navedtra 14092. Radio antenna engineering rhombic antenna circuitry. Rhombic antenna the highest development of the longwire antenna is the rhombic antenna it consists of four conductors joined to form a rhombus, or diamond shape. A rhombic antenna can be made of two obtuseangle v antennas that are placed side by side, erected in a horizontal plane, and terminated so the antenna is nonresonant and unidirectional. Advantages and liabilities of rhombic antennasedit. This kind of antennas is well known thanks to their relative high gain associated to a simple design, being the main drawback the formation of important secondary lobes in the radiation pattern. Oct 05, 2014 a rhombic antenna is a broadband directional wire antenna coinvented by edmond bruce and harald friis, in 1931, mostly commonly used in the high frequency hf or shortwave band. Personally for me it was very interesting to read the book. Rhombic antennas for television, october 1949 radio. That assumption proved to be correct as i have received letters from a wide variety of people.
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