The antenna can be fed at one corner low impedance, current fed or at the lower end of one of the vertical. According to the books it supposedly has a bidirectional pattern. Half square vs loop skywire antenna resource detail. Your opinion and comments on the half square antenna qrz. Half squares do have limited apr 21, 2014 the n9sab 20m half square antenna duration. Feed the wire across two holes to lock it in place. Half square hf antenna 20m band wire antennas uk hf. The idea for a portable half square came about while learning to use eznec 1 antenna modeling software.
The purpose of the cage is to increase the effective diameter of the antenna. Antenna projects from the yccc click on articles doublel for 80160, two wire beverage, a poor mans 160 meter 4square, using a 4 square vertical phased array to improve your 80 and 160 meter signal, from the yankee clipper contest club. Some houses dont really lend themselves to installing a halfwave dipole. Jun 07, 2012 when dimensioning this antenna i started off with the previously optimized dimensions for the pure half square.
Wire j poles for vhf are easily built, and can be used in an emergency. All parts used for the construction of the dipole can be used to construct the half square, so there is. This antenna is inherently unbalanced like a ground mounted vertical or an elevated vertical with a counterpoise. To meander a centerfed wire dipole you need to decide on how many meanders to use on each side. If you only have one support an endfed antenna may suit you better.
Perhaps there are antenna experts, makers and experimenters who have made and used one and could give me their opinion of its performance when compared to a vertical antenna. A good balun should be placed at the feedpoint to keep the pattern nice and stop any stray rf from back down the outside of the coax. A 20 meter half square antenna for qrp portable operation. An outdoor shortwave antenna will always give better results than an indoor one. If each antenna is constructed and matched well, when you transmit through the 4 square there will be little left over power to be shunted towards the dummy load. The bottoms of the verticals are all insulated from ground. Compact halfsquare for 40m band dx commander amateur. While dipoles are very efficient antennas, they are not the only way to go. Apparent gain for dx over single verticals or low horizontal antennas will seem to be greater. Describe your experience with the 20 half square antenna and tell us why you give it the rating you did required. Feb 26, 2009 ive read a number of articles which have suggested that a half square antenna is a good wire antenna for producing the low angle radiation needed for dx. Wire antenna calculator amateur radio station ws6x. For the past couple of weeks, ive been playing with endfed wire antennas. Feb 02, 2015 a half square is perhaps the secondbest dx antenna to install if you cant afford a tower and a beam the four square array is usually a little better.
Jun 07, 2012 the half square is a vertically polarized bidirectional antenna. Dipole antenna length calculator dipoles antennas are easy to build and can be very effective when placed half a wavelenth or more above ground. The vertical angle of radiation is low, in the 20 to 30 range, depending on the conductivity of the local earth. Looking back in the log, on september 14 the 4square was 3 sunits louder than the 80fthigh dipole. The half square antenna is a wire antenna with two vertical radiators fed in phase. Listed under the antennas wire category that is about wire antenans and dipoles, long wires. I decided to use two sd20 2, 20 foot telescoping fishing poles to support the antenna. I learned the hard way by working through every section of the software and joining the mmana yahoo group.
Ver2cal wire antenna actuallyaver2callyorientated resonate12wavedipolewith theearthbeingthe return half duetopoorground conduc2vitya. If each antenna is constructed and matched well, when you transmit through the 4square there will be little left over power to be shunted towards the dummy load. The main category is resonant loop antennas that is about resonant loop antennas. This calculator uses a k multiplying factor value of. The re sult is 4 dbof gain from an antenna thatsthe same length as a simple dipole see figure2. The antenna calculator above uses this formula as a starting point to calculate wire lengths for the dipole.
I swear, it is the best wire antenna out there, and to be quite frank, for the low bands where it is difficult to get a good dx antenna, you cant beat the bobtail, it will run circles around the yagis, etc. The wire between the antenna and either a transmitter or receiver is called the transmission line. The most widely used formula to calculate the approximate overall length of wire required for a dipole is. Nov 03, 2014 trying for some hf dx with a half square for 10 mhz. Using a 7 pole, i am making up the dx commander lite system. One vertical element 14wave is fed at the top where it is attached to a so. About half square antenna the resource is currently listed in in a single category. These inventions simply use the ever popular 300 ohm antenna lead in wire. A capacitance hat is on top, and the antenna is fed with a 50.
About half square vs loop skywire antenna the resource is currently listed in in a single category. K6mm 160 meter vertical a restricted space helical vertical. How much space is available for the meander dipole. The swr should appear pretty flat across the band under 1. But compared to a normal quarterwavestick its has some gain and a favourable directional pattern. The half square antenna is a great wire antenna for the dx edge. But if youve never done it, you probably have a few questions. This formula takes into consideration the capacitive endeffect from insulators which shortens the physical length requirement for the equivalent electrical length. Ive read a number of articles which have suggested that a half square antenna is a good wire antenna for producing the low angle radiation needed for dx.
For the study of meander characteristics seven antenna models were developed from 34 to 6 meanders per dipole arm. Dx was worked on 10 mhz when ea8aytm replied to a cq call but more dx was worked on 14 mhz. If a full wavelength dipole is used either for transmission or for reception, let us see how the radiation will be. What is the peak voltage present at the very end tips of halfwave dipole antenna in free space, and how might this peak voltage relate to transmitter type, transmitter power, rf frequency vs. Other useful information would include your experience with similar products, infomation on a product that you would purchase instead of this one, and so on. Getting started with mmanagal antenna analysis software. The computer optimization method was to find the length of wire that would resonate on the desired frequency after being bent into the square meander form. For people in other parts of the world that is equivalent to 1. Half square vs loop skywire antenna resource detail the.
One vertical element 14wave is fed at the top where it is attached to a so239. Apr 11, 2020 feed the wire across two holes to lock it in place. The other quarterwave wire is fed up from the verticat ih rough the holes in the plastic to lock it in place as seen in ihe diagram. Endfed wire antennas radio society of great britain. Before i get into the nittygritty details, let me first make a distinction between endfed halfwave antennas, such as the ones sold by lnr precision and endfed wires that use some kind of tuning to achieve a 50. Half square antenna radiation pattern hy power antenna company. I have run 600w to it through my tentec 229 tuner with no issues at all. The basic formula for determining the length of a center fed, halfwave wire dipole or inverted vee antenna is 468. Endfed 12 wave 30w 80m10m wire antenna endfed 12 wave 30w 80m10m wire antenna full hf coverage, no tuner needed on most frequencies. The antenna can be fed at one corner low impedance, current fed or at the lower end of one of the vertical wires high impedance, voltage fed. Ver2calwireantenna actuallyaver2callyorientated resonate12wavedipolewith theearthbeingthe return half duetopoorground conduc2vitya. This formula to obtain the length of a halfwave dipole antenna will give a good ballpark value to start with. The bottom, sides and top are the same length and at right angles to each other. I found that i could get a fairly good radiation pattern with the horizontal portion of a 20meter half square antenna only 20 feet above the ground.
Notice in the geometry tab that there is again only 1 wire, but it now has a z component only, all others are zero. Halfsquare antenna is by naturerelatively narrow band. Incidentally, all you need are two trees or masts 5. Cage dipole resonant frequency, bandwidth and endeffect of a wirecage dipole antenna each half of the dipole consists of a cylindrical cage of parallel wires, the. The ea5avl 40m compact 4square antenna was designed to provide excellent dx communications on the 40m band, utilising readily available components and be relatively easy to construct. The halfsquare is a vertically polarized antenna as long as it is kept low and parallel to the earth surface. Its a good idea to have your antenna at least one half 12 wavelength of the antenna. If traditional antenna theory says that the impedance of a half wavelength dipole in free space is around 72 ohms at resonance, and a model taking into account the wire diameter and the height about ground reports 65 ohms, and the measured value is 61 ohms, we can be more confident that we have built a form. Part ii ham radio vertical antenna build dx commander. Kb6nu finally builds an endfed, halfwave antenna kb6nu. This link is listed in our web site directory since saturday jan 31 2015, and till today half square vs loop skywire antenna has been followed for a total of 700 times.
Running a simple 100 watt transceiver i can work, cw or ssb, most anything i can hear. This dipole antenna gives the same gain as all other dipoles, however, the half square is a much better dx antenna for a given elevation and may be worth the extra effort. Vfo a on my dipole and vfo b on my vertical and i found the stereo image very. The tops of the verticals are all connected together by a wire or other conductor. The results are conveniently displayed in inches, centimeters, feet and meters. A simple halfsquare antenna for 40m is cheap and easy to build. With square meanders the antenna can theoretically be half length.
The half square wire antenna on 10 mhz and more youtube. The half square is fed in one corner and according to my mmana model, this. Antenna projects from the yccc click on articles doublel for 80160, two wire beverage, a poor mans 160 meter 4 square, using a 4 square vertical phased array to improve your 80 and 160 meter signal, from the yankee clipper contest club. After extensive testing, the power rating on the w8amz 80m reduced half sloper antenna has been increased to 1 kw ssb. Enter the desired operating frequency in megahertz to get a good starting length for a dipole in both feet and meters. Build a half square dx antenna radio amateur 051997. The antenna has been used very successfully over the 20072011 period during the sun spot minimum. Bob tail curtain or half square opinions worldwidedx.
I find it is a vertical omnidirectional antenna with some gain because of the top feed wire and in some directions is better in my opinion. A simple half square antenna for 40m is cheap and easy to build. Half square hf antenna 20m band hf wire antenna ham. Center of connector to horizontal, shield side to vertical element. Half square, double half square and bobtail curtain antennas. The halfsquare antenna a simple modification to a dipole would be to add two. The half square is fed in one corner and according to my mmana model, this should present 50 ohms and a great swr curve across the whole of 40m. The vertical elements are 17 8 long and the horizontal element is 35 5. How to build several easy antennas for amateur radio wikihow.
More important than the gain is the lowerangle of radiation from the haltsquare. What is the peak voltage at the tips of a dipole antenna. The wire is insulated and the ends protected against accidental contact with high rf voltage. Bandwidth and endeffect of a wirecage dipole antenna each half of the dipole consists of a cylindrical cage of parallel wires, the wires being connected together at their ends. Describe your experience with the hy power antenna company 40 meter halfsquare and tell us why you give it the rating you did required. See more ideas about ham radio antenna, ham radio and dipole antenna. The main category is wire antenans and dipoles, long wires that is about long wire and dipole antenans for ham radio.
In any place were the national electric code nec, that is used in much of the united states, is enforced as law the minimum size of wire that can be used for an amateur radio transmitting antenna is number fourteen american wire gauge 14awg. Nov 16, 2012 the half square is, in my opinion, the best and easiest antenna to put up and keep up. Listed under the antennasloop category that is about resonant loop antennas. Longwire antennas require a length greater than a quarterwavelength. Your opinion and comments on the half square antenna qrz forums. No long counterpoise, radials or feedline required. Compared to a horisontally polarized dipole its gain is low as it will not get the extra circa 5 db due to ground reflexion. Pvc sections bolted together, and 12 wavelength of antenna wire helically wound around the pvc sections.
The size of the wire used to make an antenna affects its performance. Part ii of the vertical antenna build, delivering any three bands from 30m and up with no atu. The rauia lion from the horizontal legs is sen canceling, but the radialion from the vertical legs is additive. The reason behind this is that like a tuning fork an antenna will perform best. This link is listed in our web site directory since tuesday jul 12 2005, and till today half square antenna has been followed for a total of 7039 times. It is always a half loop with the other half an earth image. Shown in the above picture is a representation of the actual antenna wire placement and the radiation pattern. The term grounded half loop would be an accurate descriptor. Dropping one of the wire curtains converts the same antenna into a general coverage multiband inverted l. No need for a tower, rotor, and beam to get rare dx or be competitive.
The half square is made of a two strand computer ribbon cable 100 feet long. But be warned endfed antennas can be noisier and also cause more emcinterference problems. This formula to obtain the length of a half wave dipole antenna will give a good ballpark value to start with. Wire antennas for the beginner every ham knows how to make and install wire antennas. No need for a tower, rotor, and beam to get dx on the 20 meter band. The hsq the halfsquare vertical antenna sm5jab ham radio. The half square is a shortened bobtail it has 2 quarter wave vertical elements and is a half wave long. Half square antenna radiation pattern the red line represents the horizontal radiation pattern and the blue line represents the vertical take off angle. Transmission lines come in a bewildering variety of species, but there are only a few basic types. Physical dimensions for the hsqb, expressed in wavelengths. The remainder of the cable is peeled apart to form the radiating elements.
Loop 3 multiturn, square, frame or loop receiving aerials given the. That was september 95, when the new 4square on 80 meters was being compared to a dipole. Microstrip square patch antenna using cst by shamsur rahman akash. Hours of simulations later i settled for the dimensions in the figure below. Hf half square 20 meter band antenna wire antennas uk. The half square has a beamwidth of about 60 and a gain of about 4db. Ive compared the half square at the same location with a wire groundplane and halfwave dipole. A random length outdoor wire antenna installed as high above ground and as far away from buildings and power lines as possible will generally give quite satisfactory results. The sd20 poles are made of graphite and tend to detune a resonant antenna if the wire is. The half square is made of a two strand computer ribbon cable 100 feet long, 47 feet of which is used for the balanced feed line. The fullwave dipole with its voltage and current distribution. This is a quarter wave vertical mounted on the ground. Often random wire antennas are also inaccurately referred to as longwire antenna. If traditional antenna theory says that the impedance of a half wavelength dipole in free space is around 72 ohms at resonance, and a model taking into account the wire diameter and the height about ground reports 65 ohms, and the measured value is 61 ohms, we.
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