Rhombic antennas have high directional gain and low takeoff angles and are best suited to long distance, point to point communications. The antenna is placed end to end and terminated by a noninductive resistor to produce a. Explain resonant and nonresonant modes of long wire antenna. The rhombic antenna was designed in the 1931 by edmond bruce and harald friis, it was mostly commonly used in the high frequency hf or shortwave band as a broadband directional antenna prior to world war ii, the rhombic was one of the most popular pointtopoint high frequency antenna arrays. This month, ill take another look at receive antennas for dtv.
Ideally, if we install the proper terminating impedance at the far end of lossless antenna a subject for extended discussion later, several conditions would exist. Home intelligence reference and training manuals half rhombic antenna. The half rhombic antenna is cut at the feed and resistor. After being called out, i had researched the inverted v some more, and found that it was horizontally. Prior to world war ii, the rhombic was one of the most popular pointtopoint high frequency antenna arrays. Rhombic antennas suited to operation down as low as 1.
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. Rhombic antenna works under the principle of travelling wave radiator. The rhombic antenna is a highly directional array ideally suited to medium to long haul circuits. About rhombic antenna dimensions the resource is currently listed in in a single category. Of all antennas ever conceived for longdistance with relatively simple. The rgaa has numerous bent radiation elements, forming rhombic cells and loops. A rhombic antenna is made of four sections of wire suspended parallel to the ground in a diamond or rhombus shape. 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.
The inverted v antenna or vertically polarized half rhombic is half of a standard rhombic turned on its side. Half rhombic antennas seen in b of figure 1 are designed differently, but function similarly to full rhombic antennas because of the method of images moi principle. Other readers will always be interested in your opinion of the books youve read. The rhombic antenna is an equilateral parallelogram shaped antenna. A remarkable antenna that had phenomenal directivity and an extraordinarily low elevation angle made it the antenna of choice for pointtopoint hf links. Increased parallel resistor stages will increase overall input wattage. 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. The sides of the rhombus each consist of two or more parallel conductors. Rather than tiptoe up to trying to get in stations with rotators and larger and larger deep fringe antennas i found the rhombic antenna. Apr 12, 2018 there was a time, back in the 1930s and 1940s, when the rhombic antenna was the king. The rhombic antenna is made of wire and shaped like a diamond. Van nostrand publishing, 1941, bell telephone labs series as well as full text of the 91 major u.
Bprh230 rhombic antennas have high directional gain and low takeoff angles and are best suited to long distance, point to point communications. Theoretically the terminated inverted v antenna uses the ground below the antenna to make up the missing half of the rhombic. 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. Based on the model, the input impedance, gain and directivity of a rhombic antenna are analysed by using moment method and microwave. 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. Rhombic project rp232 meteor scatter on 440 mhz page. Location and antenna helped in the days before telrex big berthas. A typical rhombic antenna design would be at a height of between a half and a full wavelength. A remarkable antenna that had phenomenal directivity and an extraordinarily low elevation angle made it the. Pdf mutual coupling effects analysis in a crossrhombic. Rhombic antenna article about rhombic antenna by the. 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. Its a well understood antenna, there is good design data for it.
A rhombic antenna is made of four sections of wire suspended parallel to the ground in a. Rhombic antennas for television, october 1949 radio. All resistors are carbon 5w, creating 10w max dissipation per leg. It is arranged in the form of a rhombus or diamond shape and suspended horizontally. Pdf in this paper, the design of a wider bandwidth antenna is presented. It has also been used for hf broadcasting but is no longer recommended for this purpose. Transmitting antennas for hf broadcasting the rhombic antenna has been extensively used for hf communications. The resonant rhombic antenna is bidirectional, while the terminated rhombic antenna is unidirectional. It shouldnt have a double beam like that, it should have a single forward beam. Rhombic antenna dimensions and plan for hf and vhf bands by n6jsx. Some years ago i became interested in a special type of antenna. 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. Kb1sgs amateur radio rhombic pages rhombic antenna design. Apr 11, 2018 there was a time, back in the 1930s and 1940s, when the rhombic antenna was the king.
Rhombic antennas have high directional gain and low takeoff. 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. Rhombic antennas category is a curation of 14 web resources on, kb1sgs rhombic pages, rhombic antenna for shortwave radio broadcasting, rhombic antennas for radio broacasting. Rhombic termination resistor termination resistor needs to be near 800. The primary requisite of a beamtype antenna for good reception is a.
We will look at a few rhombic antenna designs including an inverted v in the article below. The arrl and rsgb antenna books would also be good reading. Military hf base station antennas at communication. Radiation angles vary with the design and ground coefficient but for average ground and a height of approximately a half wavelength, the radiation angle is 35 changing to 15 at 4 fo four times the optimum frequency. You can and should design a rhombic from formulas, and only simulate at the end. To get away from all those nulls in the elevation direction you need to tilt the antenna up. Author, the antenna manual for fringe and bad ghost areas the rhombic antenna will always outperform an ordinary dipole array. Tactical directional hf antenna system 2 to 30 mhz. Rhombic antenna, a broadband directional antenna most commonly used on shortwave frequencies. Description and simulation of two types of rhombic antennas, using the software 4nec2. Rhombic antennas were the ultimate antenna design back in the golden age of wireless. The main category is rhombic antennas that is about rhombic antennas. You will loose a little gain compared to horizontal. Pdf a novel excitation source model for analysis of rhombic.
Jan 25, 2006 this month, ill take another look at receive antennas for dtv. A 3 wavelength per leg rhombic pointed up at 45 degrees should have about 10 to 11 dbi gain depending on height above ground. At hf ra rhombic antenna rhombic antennas have high directional gain and low takeoff angles and are best suited to long distance, point to point communications. Cummings, kb1sg, and is displayed here with his permission. Mutual coupling effects analysis in a cross rhombic antenna array. This cd gives you the full 112 page text of the standard reference book on rhombic antennas, rhombic antenna design by a. There was a time, back in the 1930s and 1940s, when the rhombic antenna was the king. Rhombic antenna article about rhombic antenna by the free. The frequency range of operation of a rhombic antenna is around 3mhz to 300mhz.
Download pdf version of text printerfriendly version. The rhombic antenna was designed in the 1931 by edmond bruce and harald friis, it was mostly commonly used in the high frequency hf or shortwave band as a broadband directional antenna. Rhombic antennas suited to operation down as low as 2 mhz are large. Our hf broadband biconical dipoles are highly efficient. The antenna is placed end to end and terminated by a noninductive resistor to produce a unidirectional pattern. Mar 03, 2019 welcome to kouo rhombic antenna farm, a unique blog here for you to explore. 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. Based on the principle of traveling wave and vee antenna, rhombic antenna is a very high directive antenna has diamond or rhombus shape working of rhombic antenna by properly selecting the tilt angle, the rhombic antenna will give additive effect of radiation pattern of each long wire antenna the radiation mechanism is basically depends on two. Noisier than horizontal antennas easier to hide in antenna restricted areas can be disguised as flagpole or be a single wire in a tree. Such a double antenna consists of two rhombuses that are displaced with respect to each other by 0. The rhombic antenna has for many years been a favorite for high.
If we look at this link to this pdf document on rhombic design we find suggested dimensions for rhombic antennas. 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. A rhombic grid array antenna rgaa is proposed and its frequencyscanning performance is discussed. It continues to be used for fixedservices pointtopoint links. Real terminated long wire antennas only approximate this condition. Performance of verticallypolarized, halfrhombic antennas.
There are 2 versions of the rhombic antenna, the resonant rhombic antenna and the terminated rhombic antenna. The rhombic antenna is widely used for longdistance, highfrequency transmission and reception. A practical guide to the design of rhombic aerials. Vr 23f a highly directional terminated half rhombic antenna, the vr 23f is a tactical antenna system, horizontallypolarized, suitable for.
Building installing and using large antennas has added such value to my life, and i love having the opportunity to share my passions and thoughts with my loyal readers. This link is listed in our web site directory since thursday apr 10 2008, and till today rhombic antenna dimensions has been followed for a total of 4624 times. Wire antennas for ham radio sun country amateur radio. It covers 174 mhz 192 mhz, centered around 168 mhz. Welcome to kouo rhombic antenna farm, a unique blog here for you to explore. The rhombic antenna is often claimed to be an exceptionally good antenna with very high gain. It is found that most antennas have a quite narrow bandwidth. The rhombic antenna has for many years been a favorite for highfrequency skywave transmission and reception. My article antennas for dtv reception in the march 6, 2002 column on antennas for dtv reception was published almost four years ago, yet hardly a week goes by that i dont get a request for fig. In this video, i have explained rhombic antenna by following outlines. Which if ive done this correctly means a wavelength of 1.
Directional tactical wire antenna, designed for longrange pointtopoint communications. Of course an extra 68db cant be considered a lot in these days of tubes with handles. Design a rhombic antenna to operate at 20mhz when the angle of elevation angle 10o. It is arranged in the form of a rhombus or diamond shape and suspended horizontally above the surface of the earth. May 02, 2018 in this video, i have explained rhombic antenna by following outlines. A remarkable antenna that had phenomenal directivity and an extraordinarily low elevation angle made it. Whether youve loved the book or not, if you give your honest and detailed thoughts then people will find new books that are right for them. The antenna consists of four straight wires of the same length. Wire antennas for ham radio sun country amateur radio society.
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