I have almost 700 foot spans on my european rhombic between to 100 foot utility poles, but im using 38 cables and utility hardware, i have withstood 6 years now with severe icing without any issues. There was a time, back in the 1930s and 1940s, when the rhombic antenna was the king. Obtain the vector frequency response of arbitrary 3d antenna structures. The sides of the rhombus each consist of two or more parallel conductors.
The rhombic antenna is widely used for longdistance, highfrequency transmission and reception. Antenna patterns and ghost rejection as a measure of vulnerability to ghosts, the common figure of merit for ordinary dipole arrays having a wide acceptance angle is the fronttoback ratio on each of. Rhombic antenna dimensions and plan for hf and vhf bands by n6jsx. Its appropriate than a ham is bringing up the question and trying an old design like this hams creates most early radio tech back in the early days. Rhombic antenna article about rhombic antenna by the free. Lets look at a 2 wl per leg 40meter rhombic design 120 feet high over medium conductivity soil using number 8 awg bare copper wire with an 800 ohm termination. Its a sturdy antenna if installed correctly and will withstand the ice and wind like no other. This antenna software module also helps you validate existing antenna designs and study a plethora of antenna design issues, including. 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. A typical rhombic antenna design would be at a height of between a half and a full wavelength.
A practical guide to the design of rhombic aerials. Hf dipole antenna this antenna software will help you design a simple wire dipole antennas for 1 30 mhz. From photos ive seen and regular visitors ive talked to usually 2 of the biggest glass jugs readily available for lowmedium power commercial sw at the time going back to the early 30s. The rhombic antenna is often claimed to be an exceptionally good antenna with very high gain. To gather a base set of data for half rhombic antenna impedance and radiation patterns for comparison to conductive traces, and for future research comparisons. The usa rhombic was at 18m high 54 ft and the jasa rhombic was at 12m 36 ft. The resistive load has usually a value between 600 and 800 ohms.
Apr 12, 2018 there was a time, back in the 1930s and 1940s, when the rhombic antenna was the king. Rhombic antennas for television, october 1949 radio. Designing rhombic resources suggestions wanted page 2. Com amateur radio mapping and software for radio hams. This antenna is ideal for ionospheric radio wave propagation. Find rhombic antenna terminating resistors related suppliers, manufacturers, products and specifications on globalspec a trusted source of rhombic antenna terminating resistors information. Antenna modeling used to be the domain of scientists and engineers with very expensive antenna ranges covering acres and acres of land strewn with expensive equipment. May 20, 2011 from photos ive seen and regular visitors ive talked to usually 2 of the biggest glass jugs readily available for lowmedium power commercial sw at the time going back to the early 30s. If you have a large rural property, you may want to design, build, and use a rhombic antenna something david casler ke0og calls the king of antennas. A remarkable antenna that had phenomenal directivity and an extraordinarily low elevation angle made it the antenna of the mighty rhombic, the king of antennas there was a time, back in the 1930s and 1940s, when the rhombic antenna was the king. A remarkable antenna that had phenomenal directivity and an extraordinarily low elevation angle made it the antenna of choice for pointtopoint hf links. Vhf and uhf high gain rhombic antennas for point to point.
Utilizing generalized circuit theory wherever possible, a design procedure is laid down for the single wire, unielement horizon tal rhombic antenna, whose side length is an integral number of quarter wavelengths at. 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 4631 times. The antenna is always flat, and it handles high winds and treebranch hits with ease. The rhombic loop twofer is two antennas in one a small but potent rhombic by day, and a loop skywave by night.
To gather a base set of data for halfrhombic antenna impedance and radiation patterns for comparison to conductive traces, and for future research comparisons. Antenna patterns and ghost rejection as a measure of vulnerability to ghosts, the common figure of merit for ordinary dipole arrays having a wide acceptance angle is the fronttoback ratio on each of the channels under consideration. If you have a large rural property, you may want to design, build, and use a rhombic antennasomething david casler ke0og calls the king of antennas. The antenna wants to pull the supporting masts inside, so extra guying in opposite direction away from the center of the antenna is help full. Rhombic antennas suited to operation down as low as. The results from the physical antennas were then compared to results from an antenna modeling software program. 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. This would allow us to work into south america on the back of the antenna. To make design information available to radio telephone engineers of the bell sysem. Bprh230 rhombic antennas have high directional gain and low takeoff angles and are best suited to long distance, point to point communications. Increased parallel resistor stages will increase overall input wattage. About rhombic antenna dimensions the resource is currently listed in in a single category. Apr 11, 2018 there was a time, back in the 1930s and 1940s, when the rhombic antenna was the king. Types of rhombic design alignment design maximum output design.
Jun 03, 2018 rhombic antenna, 30m6m by richard hager published june 3, 2018 updated august 12, 2018 rhombics are high gain directive wire antennas. Rhombic antenna article about rhombic antenna by the. In order to provide a dynamic response, reconfigurable antennas integrate an inner mechanism such as rf switches, varactors, mechanical actuators or tunable materials that enable the intentional redistribution of the rf. 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 rhombic antenna is a highly directional array ideally suited to medium to long haul circuits.
The antenna is placed end to end and terminated by a noninductive resistor to produce a unidirectional pattern. The antenna needs two points of suspension for ropes from the dipole end insulators. 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. Kb1sgs amateur radio rhombic pages rhombic antenna design. Some years ago i became interested in a special type of antenna. That was fine during my first quarter of century as a ham radio operator and antenna enthusiast. Rhombic antenna works under the principle of travelling wave radiator. Supplement to graphic symbols for electrical and electronics diagrams supplement to ansi y32. The resonant rhombic antenna is bidirectional, while the terminated rhombic antenna is unidirectional. The target audience for this material is the antenna enthusiast who has antenna knowledge and experience, but has thus far avoided integrating modeling into their design and thinking process.
A reconfigurable antenna is an antenna capable of modifying its frequency and radiation properties dynamically, in a controlled and reversible manner. Look for my latest antenna article, the rhombic loop twofer, in the june 2017 issue of qst. We will look at a few rhombic antenna designs including an inverted v in the article below. Mar 19, 2019 its a sturdy antenna if installed correctly and will withstand the ice and wind like no other. If we look at this link to this pdf document on rhombic design we find suggested dimensions for rhombic antennas.
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. 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. The main category is rhombic antennas that is about rhombic antennas. Ea4fsi28t1 hf antennas rhombic antennas ismael pellejero. You can design standalone antennas and build arrays of antennas using either predefined elements with parameterized geometry or arbitrary planar elements. So rhombics usually invoke big fxcking antenna on a lot of land in most engineers minds. I am fairly new to hfss, but i already made a model for a rhombic antenna using rectanglular pecs instead of cylindrical wire pecs. The antennas were to be used for dx on 40m, together with a vertical and a dipole. Rhombic termination resistor termination resistor needs to be near 800. The rhombic antenna is an equilateral parallelogram shaped 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 ranges from. 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. I have almost 700 foot spans on my european rhombic between to 100 foot utility poles, but im using 38 cables and utility hardware, i have withstood 6 years now. Software, rhombic antenna design software, vhf including oh5iys mssoft meteor scatter. A remarkable antenna that had phenomenal directivity and an extraordinarily low elevation angle made it the. The rhombic is excellent for pointtopoint communications and exhibits a very low takeoff anglea definite plus for dx. View antenna display, showing the wires making up the model of the fiveelement beam, with currents and 2d slice superimposed to show orientation. Antenna designing software instructions to build a beam for 40 m band. There are 2 versions of the rhombic antenna, the resonant rhombic antenna and the terminated rhombic antenna. Of course an extra 68db cant be considered a lot in these days of tubes with handles. 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. This design automatically equalizes tension on all legs, and has proven to work very well. Designing rhombic resources suggestions wanted page. Kb1sgs amateur radio rhombic pages a discussion on rhombic antenna design. Rhombic antennas suited to operation down as low as 1.
Rhombic antennas suited to operation down as low as 2 mhz are large. I decided to investigate antenna design software because i was tired of the traditional cutntry method. The mode of operation is a function of whether the wires at the apex are connected or. Rhombic antennas were the ultimate antenna design back in the golden age of wireless. Antenna toolbox provides functions and apps for the design, analysis, and visualization of antenna elements and arrays. 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. Obtain the radiation pattern of any antenna over a frequency range. The purpose of this page is to factually describe and illustrate the advantages and disadvantages of rhombic antennas. This 111 page bell laboratories book is filled with graphs, charts, diagrams and text covering the subject matter of rhombic antenna design. 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. But, now in my sixties, i feel i need to make more efficient and effective use of my time. Mar 23, 2017 antenna theory rhombic learn antenna theory in simple and easy steps starting from basic to advanced concepts with examples including fundamentals. Now i am making a rhombic model using cylindrical wires, but i am not sure how to get hfss to recognize the model as 3 dimensional. Free radio frequency software, antenna design and calculators.989 771 751 1550 913 1002 1364 1611 951 1142 1534 21 1380 937 1505 1382 52 42 1393 1168 758 1559 1175 36 677 1043 1454 81 1146 1494 287 655 237 1340 716 1293