L. B. Cebik, W4RNL. 1. You want to get on 160 meters for the first time (or perhaps, for the first time in a long time).

Size: px
Start display at page:

Download "L. B. Cebik, W4RNL. 1. You want to get on 160 meters for the first time (or perhaps, for the first time in a long time)."

Transcription

1 L. B. Cebik, W4RNL The following notes rest on a small set of assumptions. 1. You want to get on 160 meters for the first time (or perhaps, for the first time in a long time). 2. You want to set up the simplest possible effective antenna using all wire construction. In fact, all of the antennas will be made from AWG #14 or AWG #12 wire. 2-mm (0.0787") diameter wire falls right between these sizes, so all of the data will use that value. However, nothing much changes by reducing the diameter to AWG #14 (0.0641") or increasing the diameter to AWG #12 (0.0808"). 3. You do not have unlimited vertical space for your antenna. In these notes, the limit will be about 70'. In fact, I shall use 21 m (68.9') as the standard top height for all antennas. I have set these limits so that we can compare the performance of a collection of relatively simple antennas. For all comparisons, we shall use average ground with a conductivity of S/m and a relative permittivity (dielectric constant) of 13. For vertical antennas especially, you should expect lesser performance from worse ground and better performance from better ground--but not radically worse or better. Horizontal antennas are less affected by ground quality, but the top height is so low (about 1/8 wavelength) that the ground will influence performance much more than for the antennas you place 1 wavelength above ground for the upper HF region. 160-meter antennas are naturally much larger (longer, taller) than antennas for the other HF amateur bands. Therefore, be prepared to spend a little more money for quality wire and insulators to durably bear the antenna weight. Copperweld is desirable. Supporting structures--whether natural or constructed--need to be stronger and taller than the average sorts of things that populate a backyard. How you handle the support structures I shall leave to you, since every yard is different, as are the locally available materials and the construction skills at hand. With those qualifications, let's get started in our work, starting with some vertical antennas. 160-Meter Wire Verticals We shall begin with an antenna that violates the upper height limit of our task: the full-size 1/4-wavelength vertical monopole. A wire version of this antenna needs to be about 39 m (128') tall. The convenience of the vertical monopole is that we can feed it at the base--at or near ground level. The inconvenience is that we must install radials. The radials should be about 1/4-wavelength long and placed as symmetrically as the yard space allows. To see how many radials we might need, I modeled the vertical using 4, 16, and 64 1/4-wavelength radials, each 6" (0.15 m) below the surface. Fig. 1 shows the outlines of the 3 models. The following table shows the anticipated results, assuming that the vicinity of the antenna is not filled with RF-eating ground clutter. Conductive objects--even semi-conducting trees and shrubs--can distort antenna patterns and absorb some RF energy, so keeping the antenna area as clean as possible is important to getting the most out of any vertical antenna.

2 1/4-Wavelength Vertical Monopole with Variable Radial Systems Average Ground No. of Maximum TO Angle Feedpoint Z Radials Gain dbi degrees R +/- jx Ohms j j j12 Note that we gain about 1.2 db by increasing the radial field from 4 to 16 wires, with another increase of about 0.7 db by raising the count to 64. Fig. 2 shows the relative radiation pattern strengths. The radiation plot also shows that a vertical antenna is best for lower-angle long-distance skip signals, but almost unusable for NVIS (Near Vertical Incidence Skywave) very short distance communications. Many vertical users also find a vertical less noisy that a horizontal antenna in terms of QRN from lightning, but more susceptible to local man-made noise sources. As well, as we increase the number of radials, the impedance decreases, indicating a reduction in energy lost to the ground. As the impedance decreases due either to the number of radials or ground quality, a number of operators use a simple means of obtaining a good match for coaxial cable. By making the vertical longer, they increase the resistive component of the impedance and the reactance moves from being slightly capacitive to being more definitely inductive. Adding a series capacitor at the feedpoint between the cable center conductor and the feedpoint itself allows them to compensate for the reactance, leaving a nearly perfect match for the 50-Ohm cable. A fixed capacitor may work if you have a specific operating frequency, but a remotely tuned variable is necessary for obtaining a low SWR over a wider operating bandwidth. Since we want the antenna to be at least slightly inductively reactive at all operating frequencies, setting up the antenna for the low edge of the band is the usual practice. The full-size vertical monopole is useful as a reference for comparing other vertically polarized antenna candidates. With that data, we can see what we gain or lose from each one. We shall look at 2 candidates, each no more than 70' tall. The Tee-Vertical: If we must limit the height to a certain level--70' in our case--but still desire a perfectly circular pattern, we need to create a shorter vertical antenna. Many vertical users opt for inductively loading the vertical either at its base or higher up on the wire. However, inductive loading has two disadvantages. First, the inductor always has a series resistance that reduces the radiated energy. Second, inductive loading reduces the feedpoint impedance faster, the closer the inductor is to the feedpoint. One of the simplest and most efficient ways to shorten a vertical monopole is to create a hat at the top. The usual

3 vision of a hat consists of several hat wires radiating from the top of the vertical wire. However, we actually need only 2 wires to effect a hat. (The more wires that we have in a symmetrical arrangement, the shorter that each must be to set the antenna at resonance. However, any wires not in the same line as the supports for the top of the vertical section require additional supports.) We shall look at 3 versions of a Tee-vertical: with 4, 16, and 64 radials. Fig. 3 shows the relative complexity of each version. The vertical wire is 21 m (68.9'), and each leg of the Tee is 11.6 m (38') long. For the same set of conditions used to model the full-size vertical monopole, the shortened Tee-vertical shows the following performance values. Shortened Tee-Vertical Monopole with Variable Radial Systems Average Ground No. of Maximum TO Angle Feedpoint Z Radials Gain dbi degrees R +/- jx Ohms j j j11 The fewer the radials, the more that Tee-vertical performance lags behind the performance of the full-size vertical monopole. With 64 radials, there is almost no difference in performance with respect to gain. The Shorter vertical section of the Tee version does show a 2-degree increase in the TO angle. As well, the impedance at the feedpoint is only about 70% of the value for the full-size vertical. Fig. 4 shows the relative radiation patterns. We do not need azimuth patterns because, like the full size vertical, the Tee-vertical provides virtually a perfect circle of radiation (assuming that there are no nearby objects to distort that pattern).

4 The Tee-vertical is amenable to the use of lengthening techniques to raise the feedpoint impedance with a series capacitor to compensate for the inductive reactance. Lengthening the Tee legs (in equal amounts to preserve symmetry) saves you the trouble of increasing the height. However, you will need more horizontal space for the increased Tee-top. If you use a series capacitor at the base of the antenna, I recommend a double waterproofing case system, along with regular preventive maintenance. As well, be sure that you use a beefy capacitor able to handle the high current level at a 50-Ohm impedance. The 1/4-Wavelength Inverted-L: A second alternative for our 70' height limitation is the inverted-l. As shown in Fig. 5, the L does not worry about symmetry, but simply uses a horizontal extension of the vertical wire to reach resonance on 160 meters. Because the top is not symmetrical, the horizontal wire radiates. However, the current is lower in the horizontal part of the antenna and the pattern is not seriously distorted on 160 meters. In the model for 1.85 MHz over average ground, the horizontal wire is 19 m (62.3') for the same vertical wire used in the Tee-vertical. The performance of the inverted-l is not significantly different from the Tee, as shown by the following performance figures. Shortened Tee-Vertical Monopole with Variable Radial Systems Average Ground No. of Maximum TO Angle Feedpoint Z Radials Gain dbi degrees R +/- jx Ohms j j j11 Due to the small horizontal component of the radiation patterns, the elevation angle has increase by another degree. However, the impedance values are almost identical to the corresponding values for the Tee-vertical. Fig. 6 shows the elevation and the azimuth patterns for the inverted-l. Note that the presence of a non-symmetrical horizontal section does not allow the pattern overhead to go to nearly zero, although the level is not strong enough for effective NVIS communications. The azimuth pattern shows a slight push in the direction of the top section of the L. However, the differential is not large enough to be noticed during operation.

5 The 160-m 1/4-wavelength inverted-l has another advantage. With a wide-range tuner at the feedpoint (perhaps one of the remote tuners on today's market), the antenna is usable for general communications on virtually all of the amateur bands. Above 160-meters, the radial system acts like a good RF ground between the operating position and the antenna base, since the antenna is 1/2-wavelength or longer on all bands above 160 meters. If you choose to use a remote tuner for such an inverted-l system, add another layer of water-proofing as an additional guard against weather penetration of the tuner and the connection. For further information on multi-band use of the inverted-l, see "Straightening Out the Inverted-L." There is one temptation to avoid with the 160-meter 1/4-wavelength inverted-l. Many operators obtain rather poor results because they place the vertical section of the antenna too close to a natural or man-made support. The vertical section needs as much clearance from other objects as the corresponding part of the full-size and the Tee verticals. 160-Meter Wire Horizontal Antennas We have examined the main candidates for vertical wire antennas, although there are manmy variations on the basic designs that we have used as examples. We should also look at some horizontal basic wire antennas. Any horizontal antenna will be severely limited by the 70' height restriction that we placed on the exercise. 70' is only about 1/8-wavelength above ground, a height that is even below optimum for NVIS operation--although it will work quite well in this service. One advantage of the horizontal wire is that it does not require any radials. A second advantage--at least for our work--is that horizontal wires do not change performance characteristics very much as we change ground quality. Therefore, the use of average ground provides a good indication of operation over any soil type. Finally, there are only 2 important horizontal variations that are possible within our height restriction: linear wires and closed horizontal loops. The 1/2-Wavelength Dipole: There is no magic about the 1/2-wavelength dipole except that at resonance, it is a reasonably good match for coaxial cable. If we wish to use parallel feedline and a tuner, we can be less critical about the exact length without changing the pattern in any detectable way. Fig. 7 shows the details of our model set-up. The wire is 78 m (256') long.

6 Since we have only a single model with which to deal, our performance table is simplified. 1/2-Wavelength Horizontal Dipole 70' above Average Ground Maximum TO Angle Feedpoint Z Gain dbi degrees R +/- jx Ohms j 0 Note that the horizontal wire provides the strongest radiation (and receiving sensitivity) straight up. Fig. 8 compares the elevation pattern of the dipole with the elevation pattern for the inverted-l with 16 radials. The horizontal wire is superior for NVIS service, but inferior for long-range, low-angle service. The horizontal wire is likely to be more susceptible to lightning noise, but less susceptible to man-made noises. The patterns for the two types of antennas cross at about the 23-degree elevation mark. Despite the low height of the dipole when registered as a fraction of a wavelength, the azimuth pattern at almost any elevation angle is still bi-directional and broadside to the wire. Fig. 9 shows the azimuth pattern at a lower angle (25 degrees elevation). Radiation (and reception) off the ends of the wire is about 8-dB or about 1.5 S-units weaker than broadside to the wire.

7 Linear wires with open ends can build considerable levels of static charge unless we take measures to bleed it off as it develops. One technique is to place either a high-value resistor or an RF choke across the antenna feedpoint, ensuring that one side is connected to the coax braid--and the coax braid is well grounded. Inserting a transmission-line transformer type of balun at the feedpoint will defeat this measure by physically isolating the feedpoints from the cable braid. However, using a W2DU-type ferrite-bead choke as the balun will allow the bleed-off component to do its work. The 2-Wavelength Horizontal Loop: A closed loop antenna is more immune to static charge build-up, but has some special requirements. To understand why the heading specifies a 2-wavelength circumference for the loop horizontal antenna, we should proceed a step at a time. Let's begin with a simple square loop, like the one shown in Fig. 10. Our initial exercise will place the loop in free space and vary the circumference from 1.0 to 2.5 wavelengths. The following table lists the free-space performance values for the loop. The column marked "Horizontal Gain" lists the gain in the plane of the loop. The column labeled "Vertical Gain" shows the gain broadside to the face of the loop. Free-Space Performance of Horizontal Loops of Various Sizes Circumference Horizontal Vertical Feedpoint Z WL Gain dbi Gain dbi R +/- jx Ohms j 17

8 j j j 2700 The 1-wavelength loop is most useful in parasitic beams called quads, where the individual loops are set up vertically to take advantage of the stronger radiation broadside to the plane of the loop. However, when we place the loop horizontally over ground, the radiation from the edge of the loop--the plane of most interest--is much weaker. As the table shows, the edge, in-plane, or "horizontal" radiation is strongest when the loop is about 2 wavelengths in circumference. For our test model, that length is about 340 m (1115'). Since the loop is not resonant, we shall need parallel transmission line and a tuner. Hence, the exact length is not at all critical. Any total circumference around 1100' will work fine. Fig. 11 compares the elevation and azimuth patterns for 1 and 2 wavelength loops 70' above average ground. Note that due to the low height, even the 2-wavelength loop has a relatively high TO angle. However, the 2-wavelength radiation strength (and reception sensitivity) at lower angles is considerably greater than the 1-wavelength loop. The advantage at lower angles appears clearly in the azimuth patterns on the right. The "tilt of the pattern follows the placement of the feedpoint, shown in Fig. 10. Note that the 2-wavelength loop does not produce a circular--or even an oval--pattern. Rather, it has four wide major lobes. The following table completes the equivalent data for all of the loop sizes that we tested in free-space. Note that the impedance reports change relative to the free-space values--as a function of the low height of the antennas above ground. The resistive component is lower, while the reactive component is more inductive. Performance of Horizontal Loops of Various Sizes 70' above Average Ground Circumference Maximum TO Angle Feedpoint Z WL Gain dbi degrees R +/- jx Ohms j j j j 3300 The pattern shapes and TO angles for a horizontal loop change as we change the shape of the loop. They also change if we move the feedpoint, say, from a corner to the middle of a side. As samples of the sort of changes that we might encounter with relatively symmetrical simple structures, I modeled triangular, square, and hexagonal loops, feeding each structure both at a corner and in the middle of a side. The following table summarizes the results. It adds a column listing the maximum gain at a "standard" 30-degree elevation angle, since the TO angle is considerably higher in most cases and varies from case to case.

9 Performance of 2-Wavelength Horizontal 70' above Average Ground Loop and Maximum TO Angle Gain at 30-deg Feedpoint Z Feed positionl Gain dbi degrees dbi R +/- jx Ohms Triangle-Corner j 315 Triangle-Side j 300 Square-Corner j 220 Square-Side j 380 Hexagon-Corner j 320 Hexagob-Side j 320 The wires of a 2-wavelength loop interact with each other to produce distinctive patterns for each combination of overall shape and feedpoint placement. Fig. 12 shows the azimuth patterns for the two triangles, with plots taken at the TO angle at at a standard 30-degree elevation angle. The insets show the loop outline and the feedpoint placement relative to the pattern for each version of the triangle. In all of the plots of 2-wavelength horizontal loops, the feedpoint will be at the top or 0-degree azimuth direction. The two triangle patterns are similar, although there is a small displacement of the pattern toward the long-wire side and away from the triangle point. More significant is the fact that in both cases, the pattern is significantly stronger (by about 3 db) along a line from the feedpoint through the center than from side to side. Otherwise, there is not much to choose between the two versions of the triangle.

10 The patterns in Fig. 13 confirm what the data in the table suggest: the feedpoint position makes a much more important difference to performance with a square loop than with any other form. With a corner feed, we obtain nearly circular patterns, but at lower strength. With a side-feed, we obtain more gain, but the patterns take on the 4-lobe shape. The lower the elevation angle, the more distinct that the lobes become. Whether the pattern shape and gain provide an advantage may depend on the possibilities for laying out the antenna relative to desired communication targets. As we make the loop more circular, the exact shape and feedpoint make less difference to performance. The hexagon patterns appear in Fig. 14. Neither the pattern shape nor the gain change very much as we re-orient the loop and the feedpoint. As well, the corner-fed and side-fed versions of the loop exhibit feedpoint impedance values that are much closer together than for either the triangle or the square.

11 The most desirable version of a 2-wavelength horizontal loop would be a circle. However, the realities of antenna construction will not only require simpler forms, but as well, they may dictate somewhat irregular shapes. Nonetheless, virtually any horizontal loop will provide very reasonable performance. In addition, unlike a dipole, they will provide a null overhead, much like the nulls of vertical antennas. Therefore, if NVIS operation is the goal, you much either create a 1-wavelength loop or a dipole. For operation in the degree elevation range, the 2-wavelength loop will usually provide as much or more gain than a wire vertical. Fig. 15 compares the elevation patterns of the corner-fed hex loop and the inverted-l with 16 radials. The maximum gain limits of the loop are similar to those of the dipole at the same 70' height, but the pattern is nearly circular rather than being bi-directional. Both the 160-meter dipole and the 2-wavelength loop are useful as multi-band antennas if we feed them with parallel transmission line and employ an antenna tuner to achieve a match with the transceiver. A number of other items at this site address the kinds of patterns that we can expect from a 250+' doublet and from horizontal loops (HOHPLs) of various shapes across the HF region. Conclusion We have surveyed some of the simplest antennas used on 160 meters. They are simple in principle, but require a lot of wire, whether used in the element or in radials. Insulation on the wire makes virtually no difference to performance. As noted early on, element wire should be strong, and copperweld is desirable. However, radials may use virtually any wire available. If a sale on wire allows you to add more radials to a vertical system, then it is worth the price. However, exposed elements require good strength or additional supports. As well, use good non-conductive insulators wherever an elevated wire terminates or changes direction. Do not lay a wire directly over a tree limb or wood support. High voltage has been known to gradually sever limbs or to set dry limbs ablaze. Suspend an insulator below the support and run the wire through the insulator. Likewise, use a strain relief fixture for any connection between the element and parallel transmission line. We have not examined a number of excellent antenna systems, such as phased or parasitic verticals. 160-meter wire Yagis and LPDAs are also possible. These are advanced projects, and our mission was to set out and compare some basic antennas. However, eventually, you will wish to purchase a copy of ON4UN's book on Low-Band DXing. It is possibly the best collection of 160-meter (and 80- and 40-meter) antenna ideas available.

A Triangle for the Short Vertical

A Triangle for the Short Vertical 1 von 11 03.03.2015 12:37 A Triangle for the Short Vertical Operator L. B. Cebik, W4RNL Last month, I described a triangle array of three full-size vertical dipoles for 40 meters (with 30 meters as a bonus).

More information

Chapter 6 Antenna Basics. Dipoles, Ground-planes, and Wires Directional Antennas Feed Lines

Chapter 6 Antenna Basics. Dipoles, Ground-planes, and Wires Directional Antennas Feed Lines Chapter 6 Antenna Basics Dipoles, Ground-planes, and Wires Directional Antennas Feed Lines Some General Rules Bigger is better. (Most of the time) Higher is better. (Most of the time) Lower SWR is better.

More information

4/29/2012. General Class Element 3 Course Presentation. Ant Antennas as. Subelement G9. 4 Exam Questions, 4 Groups

4/29/2012. General Class Element 3 Course Presentation. Ant Antennas as. Subelement G9. 4 Exam Questions, 4 Groups General Class Element 3 Course Presentation ti ELEMENT 3 SUB ELEMENTS General Licensing Class Subelement G9 Antennas and Feedlines 4 Exam Questions, 4 Groups G1 Commission s Rules G2 Operating Procedures

More information

Last year I described several Low Band RX antennas that would enable you to hear DX stations on 160, 80 and 40M. This will show you how to build

Last year I described several Low Band RX antennas that would enable you to hear DX stations on 160, 80 and 40M. This will show you how to build Last year I described several Low Band RX antennas that would enable you to hear DX stations on 160, 80 and 40M. This will show you how to build transmit antennas that will help you break the pileups!

More information

General License Class Chapter 6 - Antennas. Bob KA9BHD Eric K9VIC

General License Class Chapter 6 - Antennas. Bob KA9BHD Eric K9VIC General License Class Chapter 6 - Antennas Bob KA9BHD Eric K9VIC Learning Objectives Teach you enough to get all the antenna questions right during the VE Session Learn a few things from you about antennas

More information

The Fabulous Dipole. Ham Radio s Most Versatile Antenna

The Fabulous Dipole. Ham Radio s Most Versatile Antenna The Fabulous Dipole Ham Radio s Most Versatile Antenna 1 What is a Dipole? Gets its name from its two halves One leg on each side of center Each leg is the same length It s a balanced antenna The voltages

More information

CHAPTER 8 ANTENNAS 1

CHAPTER 8 ANTENNAS 1 CHAPTER 8 ANTENNAS 1 2 Antennas A good antenna works A bad antenna is a waste of time & money Antenna systems can be very inexpensive and simple They can also be very expensive 3 Antenna Considerations

More information

Beams and Directional Antennas

Beams and Directional Antennas Beams and Directional Antennas The Horizontal Dipole Our discussion in this chapter is about the more conventional horizontal dipole and the simplified theory behind dipole based designs. For clarity,

More information

Basic Wire Antennas. Part II: Loops and Verticals

Basic Wire Antennas. Part II: Loops and Verticals Basic Wire Antennas Part II: Loops and Verticals A loop antenna is composed of a single loop of wire, greater than a half wavelength long. The loop does not have to be any particular shape. RF power can

More information

4 Antennas as an essential part of any radio station

4 Antennas as an essential part of any radio station 4 Antennas as an essential part of any radio station 4.1 Choosing an antenna Communicators quickly learn two antenna truths: Any antenna is better than no antenna. Time, effort and money invested in the

More information

Chapter 5.0 Antennas Section 5.1 Theory & Principles

Chapter 5.0 Antennas Section 5.1 Theory & Principles Chapter 5.0 Antennas Section 5.1 Theory & Principles G3C11 (B) p.135 Which of the following antenna types will be most effective for skip communications on 40-meters during the day? A. A vertical antenna

More information

An SWR-Feedline-Reactance Primer Part 1. Dipole Samples

An SWR-Feedline-Reactance Primer Part 1. Dipole Samples An SWR-Feedline-Reactance Primer Part 1. Dipole Samples L. B. Cebik, W4RNL Introduction: The Dipole, SWR, and Reactance Let's take a look at a very common antenna: a 67' AWG #12 copper wire dipole for

More information

Page 1The VersaTee Vertical 60m, 80m Modular Antenna System Tutorial Manual

Page 1The VersaTee Vertical 60m, 80m Modular Antenna System Tutorial Manual Page 1The VersaTee Vertical 60m, 80m Modular Antenna System Tutorial Manual by: Lou Rummel, KE4UYP Page 1 In the world of low band antennas this antenna design is unique in many different ways. 1. It is

More information

ANTENNAS. I will mostly be talking about transmission. Keep in mind though, whatever is said about transmission is true of reception.

ANTENNAS. I will mostly be talking about transmission. Keep in mind though, whatever is said about transmission is true of reception. Reading 37 Ron Bertrand VK2DQ http://www.radioelectronicschool.com ANTENNAS The purpose of an antenna is to receive and/or transmit electromagnetic radiation. When the antenna is not connected directly

More information

Technician License. Course

Technician License. Course Technician License Course Technician License Course Chapter 4 Lesson Plan Module - 9 Antenna Fundamentals Feed Lines & SWR The Antenna System The Antenna System Antenna: Transforms current into radio waves

More information

The Three L-Antennas Wide Equal - Tall

The Three L-Antennas Wide Equal - Tall Wide Equal - Tall Dick Reid, KK4OBI A space saving antenna in the form of an upright L has been around the amateur radio world for a long time. References are found back to a QST article in the 60 s (Reference

More information

How Much Coaxial Cable? A Case Study. L. B. Cebik, W4RNL

How Much Coaxial Cable? A Case Study. L. B. Cebik, W4RNL How Much Coaxial Cable? A Case Study L. B. Cebik, W4RNL Newcomers to amateur radio sometimes encounter wire antenna advertisements that recommend the use of long runs of coaxial cable from the antenna

More information

RX Directional Antennas. Detuning of TX Antennas.

RX Directional Antennas. Detuning of TX Antennas. 1. Models Impact of Resonant TX antennas on the Radiation Pattern of RX Directional Antennas. Detuning of TX Antennas. Chavdar Levkov, lz1aq@abv.bg, www.lz1aq.signacor.com 2-element small loops and 2-element

More information

Antennas and Propagation Chapters T4, G7, G8 Antenna Fundamentals, More Antenna Types, Feed lines and Measurements, Propagation

Antennas and Propagation Chapters T4, G7, G8 Antenna Fundamentals, More Antenna Types, Feed lines and Measurements, Propagation Antennas and Propagation Chapters T4, G7, G8 Antenna Fundamentals, More Antenna Types, Feed lines and Measurements, Propagation =============================================================== Antenna Fundamentals

More information

MFJ-219/219N 440 MHz UHF SWR Analyzer TABLE OF CONTENTS

MFJ-219/219N 440 MHz UHF SWR Analyzer TABLE OF CONTENTS MFJ-219/219N 440 MHz UHF SWR Analyzer TABLE OF CONTENTS Introduction...2 Powering The MFJ-219/219N...3 Battery Installation...3 Operation Of The MFJ-219/219N...4 SWR and the MFJ-219/219N...4 Measuring

More information

Antennas 101 Don t Be a 0.97 db Weakling! Ward Silver NØAX

Antennas 101 Don t Be a 0.97 db Weakling! Ward Silver NØAX Antennas 101 Don t Be a 0.97 db Weakling! Ward Silver NØAX Overview Antennas 101 2 Overview Basic Antennas: Ground Plane / Dipole How Gain and Nulls are Formed How Phased Arrays Work How Yagis Work (simplified)

More information

Weekend Antennas No. 5 The "Compact Quad" Multiband Antenna

Weekend Antennas No. 5 The Compact Quad Multiband Antenna Weekend Antennas No. 5 The "Compact Quad" Multiband Antenna When I relocated to Johannesburg I needed a new multiband HF antenna. Since I was staying in a rented house a tower was out of the question,

More information

Technician License Course Chapter 4. Lesson Plan Module 9 Antenna Fundamentals, Feed Lines & SWR

Technician License Course Chapter 4. Lesson Plan Module 9 Antenna Fundamentals, Feed Lines & SWR Technician License Course Chapter 4 Lesson Plan Module 9 Antenna Fundamentals, Feed Lines & SWR The Antenna System Antenna: Transforms current into radio waves (transmit) and vice versa (receive). Feed

More information

Other Arrays CHAPTER 12

Other Arrays CHAPTER 12 CHAPTER 12 Other Arrays Chapter 11 on phased arrays only covered arrays made of vertical (omnidirectional) radiators. You can, of course, design phased arrays using elements that, by themselves, already

More information

Least understood topics by most HAMs RF Safety Ground Antennas Matching & Feed Lines

Least understood topics by most HAMs RF Safety Ground Antennas Matching & Feed Lines Least understood topics by most HAMs RF Safety Ground Antennas Matching & Feed Lines Remember this question from the General License Exam? G0A03 (D) How can you determine that your station complies with

More information

The first thing to realize is that there are two types of baluns: Current Baluns and Voltage Baluns.

The first thing to realize is that there are two types of baluns: Current Baluns and Voltage Baluns. Choosing the Correct Balun By Tom, W8JI General Info on Baluns Balun is an acronym for BALanced to UNbalanced, which describes certain circuit behavior in a transmission line, source or load. Most communications

More information

TABLE OF CONTENTS. 2.2 Monopoles Characteristics of a l/4 Monopole Folded Monopoles. 2.3 Bibliography. Antenna Fundamentals 1-1

TABLE OF CONTENTS. 2.2 Monopoles Characteristics of a l/4 Monopole Folded Monopoles. 2.3 Bibliography. Antenna Fundamentals 1-1 TABLE OF CONTENTS 2.1 Dipoles 2.1.1 Radiation Patterns 2.1.2 Effects of Conductor Diameter 2.1.3 Feed Point Impedance 2.1.4 Effect of Frequency on Radiation Pattern 2.1.5 Folded Dipoles 2.1.6 Vertical

More information

Newcomers And Elmers Net: Wire Antennas Robert AK3Q

Newcomers And Elmers Net: Wire Antennas Robert AK3Q Newcomers And Elmers Net: Wire Antennas 02-07-16 Robert AK3Q Wire antennas represent one of the greatest values in the radio hobby world. For less than the cost of a good meal out on the town you can buy

More information

One I had narrowed the options down, I installed some wire and started testing.

One I had narrowed the options down, I installed some wire and started testing. Loft & Attic antennas for restricted spaces - M. Ehrenfried G8JNJ I ve recently been looking at designs for an efficient antenna that would fit in a loft. I hoped to find something that would work on with

More information

Cray Valley Radio Society. Real Life Wire Antennas

Cray Valley Radio Society. Real Life Wire Antennas Cray Valley Radio Society Real Life Wire Antennas 1 The basic dipole The size of an antenna is determined by the wavelength of operation In free space: ~3x10 8 m/s Frequency x Wavelength = Speed of Light,

More information

Technician Licensing Class. Antennas

Technician Licensing Class. Antennas Technician Licensing Class Antennas Antennas A simple dipole mounted so the conductor is parallel to the Earth's surface is a horizontally polarized antenna. T9A3 Polarization is referenced to the Earth

More information

Antennas Demystified Antennas in Emergency Communications. Scott Honaker N7SS

Antennas Demystified Antennas in Emergency Communications. Scott Honaker N7SS Antennas Demystified Antennas in Emergency Communications Scott Honaker N7SS Importance of Antennas Antennas are more important than the radio A $5000 TV with rabbit ears will have a lousy picture Antennas

More information

L. B. Cebik, W4RNL. Basic Transmission Line Properties

L. B. Cebik, W4RNL. Basic Transmission Line Properties L. B. Cebik, W4RNL In the course of developing this collection of notes, I have had occasion to use and to refer to both series and parallel coaxial cable assemblies. Perhaps a few notes specifically devoted

More information

Technician Licensing Class T9

Technician Licensing Class T9 Technician Licensing Class T9 Amateur Radio Course Monroe EMS Building Monroe, Utah January 11/18, 2014 January 22, 2014 Testing Session Valid dates: July 1, 2010 June 30, 2014 Amateur Radio Technician

More information

FCC Technician License Course

FCC Technician License Course FCC Technician License Course 2014-2018 FCC Element 2 Technician Class Question Pool Presented by: Tamiami Amateur Radio Club (TARC) WELCOME To the third of 4, 3-hour classes presented by TARC to prepare

More information

UNIT Write short notes on travelling wave antenna? Ans: Travelling Wave Antenna

UNIT Write short notes on travelling wave antenna? Ans:   Travelling Wave Antenna UNIT 4 1. Write short notes on travelling wave antenna? Travelling Wave Antenna Travelling wave or non-resonant or aperiodic antennas are those antennas in which there is no reflected wave i.e., standing

More information

1) Transmission Line Transformer a. First appeared on the scene in 1944 in a paper by George Guanella as a transmission line transformer, the 1:1

1) Transmission Line Transformer a. First appeared on the scene in 1944 in a paper by George Guanella as a transmission line transformer, the 1:1 1) Transmission Line Transformer a. First appeared on the scene in 1944 in a paper by George Guanella as a transmission line transformer, the 1:1 Guanella Balun is the basic building Balun building block.

More information

A Beginner s Guide to Modeling With NEC

A Beginner s Guide to Modeling With NEC By L. B. Cebik, W4RNL A Beginner s Guide to Modeling With NEC Part 3 Sources, grounds and sweeps Once we progress beyond the construction of models and the interpretation of plot patterns, our next set

More information

Coming next: Wireless antennas for beginners

Coming next: Wireless antennas for beginners Coming next: Wireless antennas for beginners In other rooms: Logbook of the World (Sussex Suite) SO2R contest operation (Stable Suite) Wires for your wireless: Simple wire antennas for beginners dominic

More information

HF Wire Antennas with Gain

HF Wire Antennas with Gain Learning Unit 5 HF Wire Antennas with Gain Objectives and Overview: Take the student to the next step beyond the half-wave dipole and introduce wire antennas with enhanced directivity and gain. The concept

More information

Feed Line Currents for Neophytes.

Feed Line Currents for Neophytes. Feed Line Currents for Neophytes. This paper discusses the sources of feed line currents and the methods used to control them. During the course of this paper two sources of feed line currents are discussed:

More information

Transforms and electrical signal into a propagating electromagnetic wave OR vise versa. - Transducer goes both ways. TX and RX antennas have

Transforms and electrical signal into a propagating electromagnetic wave OR vise versa. - Transducer goes both ways. TX and RX antennas have Gary Rondeau AF7NX Transforms and electrical signal into a propagating electromagnetic wave OR vise versa. - Transducer goes both ways. TX and RX antennas have different jobs. For TX want to generate as

More information

A short, off-center fed dipole for 40 m and 20 m by Daniel Marks, KW4TI

A short, off-center fed dipole for 40 m and 20 m by Daniel Marks, KW4TI A short, off-center fed dipole for 40 m and 20 m by Daniel Marks, KW4TI Version 2017-Nov-7 Abstract: This antenna is a 20 to 25 foot long (6.0 m to 7.6 m) off-center fed dipole antenna for the 20 m and

More information

4/25/2012. Supplement T9. 2 Exam Questions, 2 Groups. Amateur Radio Technician Class T9A: T9A: T9A: T9A:

4/25/2012. Supplement T9. 2 Exam Questions, 2 Groups. Amateur Radio Technician Class T9A: T9A: T9A: T9A: Amateur Radio Technician Class Element 2 Course Presentation ti ELEMENT 2 SUB-ELEMENTS Technician Licensing Class Supplement T9 Antennas, Feedlines 2 Exam Questions, 2 Groups T1 - FCC Rules, descriptions

More information

ANTENNA BASICS FOR BEGINNERS

ANTENNA BASICS FOR BEGINNERS ANTENNA BASICS FOR BEGINNERS PART 2 -DIPOLES DIPOLES -General MULTIBAND DIPOLES RF CHOKES 1 DIPOLES Several different variations of the dipole are also used, such as the folded dipole, short dipole, cage

More information

RF Ground, Counterpoises, and Elevated Radials. Graham King G3XSD

RF Ground, Counterpoises, and Elevated Radials. Graham King G3XSD RF Ground, Counterpoises, and Elevated Radials Graham King G3XSD Ground is ground,right? Not really! There is a notion of 'ground' as the 'big zero', a charge reservoir that is so huge that no matter how

More information

CHAPTER 5 PRINTED FLARED DIPOLE ANTENNA

CHAPTER 5 PRINTED FLARED DIPOLE ANTENNA CHAPTER 5 PRINTED FLARED DIPOLE ANTENNA 5.1 INTRODUCTION This chapter deals with the design of L-band printed dipole antenna (operating frequency of 1060 MHz). A study is carried out to obtain 40 % impedance

More information

ANTENNAS Wires, Verticals and Arrays

ANTENNAS Wires, Verticals and Arrays ANTENNAS Wires, Verticals and Arrays Presented by Pete Rimmel N8PR 2 1 Tonight we are going to talk about antennas. Anything that will conduct electricity can be made to radiate RF can be called an antenna.

More information

"Natural" Antennas. Mr. Robert Marcus, PE, NCE Dr. Bruce C. Gabrielson, NCE. Security Engineering Services, Inc. PO Box 550 Chesapeake Beach, MD 20732

Natural Antennas. Mr. Robert Marcus, PE, NCE Dr. Bruce C. Gabrielson, NCE. Security Engineering Services, Inc. PO Box 550 Chesapeake Beach, MD 20732 Published and presented: AFCEA TEMPEST Training Course, Burke, VA, 1992 Introduction "Natural" Antennas Mr. Robert Marcus, PE, NCE Dr. Bruce C. Gabrielson, NCE Security Engineering Services, Inc. PO Box

More information

Amateur Extra Manual Chapter 9.4 Transmission Lines

Amateur Extra Manual Chapter 9.4 Transmission Lines 9.4 TRANSMISSION LINES (page 9-31) WAVELENGTH IN A FEED LINE (page 9-31) VELOCITY OF PROPAGATION (page 9-32) Speed of Wave in a Transmission Line VF = Velocity Factor = Speed of Light in a Vacuum Question

More information

Table of Contents. MFJ-1778 G5RV Multiband Antenna

Table of Contents. MFJ-1778 G5RV Multiband Antenna Table of Contents MFJ-1778 G5RV Multiband Antenna Introduction... 1 Theory Of Operation... 1 80 meter band:... 1 40 meter band:... 1 30 meter band:... 2 20 meter band:... 2 17 meter band:... 2 15 meter

More information

DO NOT COPY. Basic HF Antennas. Bill Shanney, W6QR

DO NOT COPY. Basic HF Antennas. Bill Shanney, W6QR Basic HF Antennas Bill Shanney, W6QR When I was first licensed in 1961 I didn t know much about antennas. I put up the longest wire that fit on my parent s lot at the lofty height of 25 and fed it with

More information

TBARC Programs Antenna Modeling with 4NEC2. By Randy Rogers AD7ZU 2010

TBARC Programs Antenna Modeling with 4NEC2. By Randy Rogers AD7ZU 2010 TBARC Programs Antenna Modeling with 4NEC2 By Randy Rogers AD7ZU 2010 Getting Started 4NEC2 is a completely free windows based tool suite to aid in the design and optimization of antenna systems 4NEC2

More information

Development of a noval Switched Beam Antenna for Communications

Development of a noval Switched Beam Antenna for Communications Master Thesis Presentation Development of a noval Switched Beam Antenna for Communications By Ashraf Abuelhaija Supervised by Prof. Dr.-Ing. Klaus Solbach Institute of Microwave and RF Technology Department

More information

stacking broadside collinear

stacking broadside collinear stacking broadside collinear There are three primary types of arrays, collinear, broadside, and endfire. Collinear is pronounced co-linear, and we may think it is spelled colinear, but the correct spelling

More information

MFJ-249B HF/VHF SWR ANALYZER

MFJ-249B HF/VHF SWR ANALYZER TABLE OF CONTENTS MFJ-249B... 2 Introduction... 2 Powering The MFJ-249B... 3 Battery Installation... 3 Alkaline Batteries... 3 NiCd Batteries... 4 Power Saving Mode... 4 Operation Of The MFJ-249B...5 SWR

More information

Half-Wave Dipole. Radiation Resistance. Antenna Efficiency

Half-Wave Dipole. Radiation Resistance. Antenna Efficiency Antennas Simple Antennas Isotropic radiator is the simplest antenna mathematically Radiates all the power supplied to it, equally in all directions Theoretical only, can t be built Useful as a reference:

More information

Portable Vertical Antenna for 75m & 40m

Portable Vertical Antenna for 75m & 40m Portable Vertical Antenna for 75m & 40m BOXBORO August 2012 Jacques VE2AZX Web: ve2azx.net 1 Objectives 1- Portable Antenna for 75m et 40m 2- Low radiation angle for DX 3- Efficient 4- Easy to install.

More information

Broadband Antenna. Broadband Antenna. Chapter 4

Broadband Antenna. Broadband Antenna. Chapter 4 1 Chapter 4 Learning Outcome At the end of this chapter student should able to: To design and evaluate various antenna to meet application requirements for Loops antenna Helix antenna Yagi Uda antenna

More information

Technician License. Course

Technician License. Course Technician License Course Technician License Course Chapter 4 Lesson Plan Module - 10 Practical Antennas The Dipole Most basic antenna The Dipole Most basic antenna The Dipole Total length is ½ wavelength

More information

The Long Wire Loop: an Omnidirectional, Multiband, Low Angle Radiator. By Steve Cerwin, WA5FRF

The Long Wire Loop: an Omnidirectional, Multiband, Low Angle Radiator. By Steve Cerwin, WA5FRF The Long Wire Loop: an Omnidirectional, Multiband, Low Angle Radiator By Steve Cerwin, WA5FRF Introduction: Something Old and Something New As the name implies, long wire loop is a marriage of the venerable

More information

Milton Keynes Amateur Radio Society (MKARS)

Milton Keynes Amateur Radio Society (MKARS) Milton Keynes Amateur Radio Society (MKARS) Intermediate Licence Course Feeders Antennas Matching (Worksheets 31, 32 & 33) MKARS Intermediate Licence Course - Worksheet 31 32 33 Antennas Feeders Matching

More information

Array Solutions Four Square Array Manual and User s Guide

Array Solutions Four Square Array Manual and User s Guide Array Solutions Four Square Array Manual and User s Guide Array Solutions Four Square Array Pattern Steering System Congratulations! You have selected one of the finest phased array steering systems made.

More information

EMG4066:Antennas and Propagation Exp 1:ANTENNAS MMU:FOE. To study the radiation pattern characteristics of various types of antennas.

EMG4066:Antennas and Propagation Exp 1:ANTENNAS MMU:FOE. To study the radiation pattern characteristics of various types of antennas. OBJECTIVES To study the radiation pattern characteristics of various types of antennas. APPARATUS Microwave Source Rotating Antenna Platform Measurement Interface Transmitting Horn Antenna Dipole and Yagi

More information

Chapter 6 Broadband Antenna. 1. Loops antenna 2. Heliksantenna 3. Yagi uda antenna

Chapter 6 Broadband Antenna. 1. Loops antenna 2. Heliksantenna 3. Yagi uda antenna Chapter 6 Broadband Antenna 1. Loops antenna 2. Heliksantenna 3. Yagi uda antenna 1 Design A broadband antenna should have acceptable performance (determined by its pattern, gain and/or feed-point impedance)

More information

Antenna? What s That? Chet Thayer WA3I

Antenna? What s That? Chet Thayer WA3I Antenna? What s That? Chet Thayer WA3I Space: The Final Frontier Empty Space (-Time) Four dimensional region that holds everything Is Permeable : It requires energy to set up a magnetic field within it.

More information

ANTENNA THEORY WAVE PROPAGATION HF ANTENNAS

ANTENNA THEORY WAVE PROPAGATION HF ANTENNAS ANTENNA THEORY WAVE PROPAGATION & HF ANTENNAS FREQUENCY SPECTRUM INFORMATION Frequency range American designator below 300 Hz..ELF (extremely Low Frequency) 300-3000 Hz..ILF (Intermediate Low Frequency)

More information

Traveling Wave Antennas

Traveling Wave Antennas Traveling Wave Antennas Antennas with open-ended wires where the current must go to zero (dipoles, monopoles, etc.) can be characterized as standing wave antennas or resonant antennas. The current on these

More information

Yagi beam antennas CHAPTER 10 COMPOSITION OF A BEAM ANTENNA _

Yagi beam antennas CHAPTER 10 COMPOSITION OF A BEAM ANTENNA _ CHAPTER 10 Yagi beam antennas The Yagi beam antenna (more correctly, the Yagi Uda antenna, after both of the designers of Tohoku University in Japan 1926) is unidirectional. It can be vertically polarized

More information

The New and Improved Carolina Windom Antenna and ½ Wave End Fed 20 Meter Vertical and Sloping Wire Antennas. EZNEC analysis by Pete Rimmel, N8PR

The New and Improved Carolina Windom Antenna and ½ Wave End Fed 20 Meter Vertical and Sloping Wire Antennas. EZNEC analysis by Pete Rimmel, N8PR The New and Improved Carolina Windom Antenna and ½ Wave End Fed 20 Meter Vertical and Sloping Wire Antennas EZNEC analysis by Pete Rimmel, N8PR Keeps RF off the Coax below this point / (part of)/ That

More information

General Class License Theory III. Dick Grote K6PBF

General Class License Theory III. Dick Grote K6PBF General Class License Theory III Dick Grote K6PBF K6pbfdick@gmail.com 1 Introduction In this session we will learn about: Feed Lines Antennas Safety As in the other theory classes, we will try to present

More information

Low Band Receiving Antennas

Low Band Receiving Antennas Low Band Receiving Antennas (on a city lot) Ned Stearns, AA7A How do you know you need a Receive Antenna? Scenario #1 Many DX stations hear you much better than you hear them Scenario #2 When your DXerneighbor

More information

Antenna Fundamentals

Antenna Fundamentals HTEL 104 Antenna Fundamentals The antenna is the essential link between free space and the transmitter or receiver. As such, it plays an essential part in determining the characteristics of the complete

More information

9el 144MHZ LFA YAGI ASSEMBLY & INSTALLATION MANUAL

9el 144MHZ LFA YAGI ASSEMBLY & INSTALLATION MANUAL 1 9el 144MHZ LFA YAGI ASSEMBLY & INSTALLATION MANUAL 2 WARNING EXTREME CAUTION SHOULD BE TAKEN WHEN CONSTRUCTING AND ERECTING ANTENNA SYSTEMS NEAR POWER AND TELEPHONE LINES. SERIOUS INJURY OR DEATH CAN

More information

CHAPTER - 6 PIN DIODE CONTROL CIRCUITS FOR WIRELESS COMMUNICATIONS SYSTEMS

CHAPTER - 6 PIN DIODE CONTROL CIRCUITS FOR WIRELESS COMMUNICATIONS SYSTEMS CHAPTER - 6 PIN DIODE CONTROL CIRCUITS FOR WIRELESS COMMUNICATIONS SYSTEMS 2 NOTES 3 INTRODUCTION PIN DIODE CONTROL CIRCUITS FOR WIRELESS COMMUNICATIONS SYSTEMS Chapter 6 discusses PIN Control Circuits

More information

Improved Ionospheric Propagation With Polarization Diversity, Using A Dual Feedpoint Cubical Quad Loop

Improved Ionospheric Propagation With Polarization Diversity, Using A Dual Feedpoint Cubical Quad Loop Improved Ionospheric Propagation With Polarization Diversity, Using A Dual Feedpoint Cubical Quad Loop by George Pritchard - AB2KC ab2kc@optonline.net Introduction This Quad antenna project covers a practical

More information

Range Considerations for RF Networks

Range Considerations for RF Networks TI Technology Days 2010 Range Considerations for RF Networks Richard Wallace Abstract The antenna can be one of the most daunting components of wireless designs. Most information available relates to large

More information

Easy to Build Low Band Receiving Antennas for Small and Large Lots

Easy to Build Low Band Receiving Antennas for Small and Large Lots Easy to Build Low Band Receiving Antennas for Small and Large Lots Small antennas High performance antennas Quantitative performance evaluation Frank Donovan W3LPL Why Receiving Antennas? Much better performance

More information

Antenna Design for FM-02

Antenna Design for FM-02 Antenna Design for FM-02 I recently received my FM-02 FM transmitter which I purchased from WLC. I researched the forum on what antennas where being used by the DIY community and found a nice write-up

More information

The design of Ruthroff broadband voltage transformers M. Ehrenfried G8JNJ

The design of Ruthroff broadband voltage transformers M. Ehrenfried G8JNJ The design of Ruthroff broadband voltage transformers M. Ehrenfried G8JNJ Introduction I started investigating balun construction as a result of various observations I made whilst building HF antennas.

More information

Jacques Audet VE2AZX. Nov VE2AZX 1

Jacques Audet VE2AZX. Nov VE2AZX 1 Jacques Audet VE2AZX VE2AZX@amsat.org Nov. 2006 VE2AZX 1 - REASONS FOR USING A BALUN - TYPES OF BALUNS - CHECK YOUR BALUN WITH AN SWR ANALYZER - MEASURING THE IMPEDANCE OF A NUMBER OF FERRITES - IMPEDANCE

More information

Antennas and Stuff. John Kernkamp WB4YJT

Antennas and Stuff. John Kernkamp WB4YJT Antennas and Stuff John Kernkamp WB4YJT John Kraus W8JK June 28, 1910 - July 18, 2004 Invented the helical antenna, the corner reflector, and the W8JK End-Fire array. In 1950 designed and built the Big

More information

Experimental Determination of Ground System Performance for HF Verticals Part 2 Excessive Loss in Sparse Radial Screens

Experimental Determination of Ground System Performance for HF Verticals Part 2 Excessive Loss in Sparse Radial Screens Rudy Severns, N6LF PO Box 589, Cottage Grove, OR 97424; n6lf@arrl.net Experimental Determination of Ground System Performance for HF Verticals Part 2 Excessive Loss in Sparse Radial Screens These experimental

More information

Welcome to AntennaSelect Volume 1 August 2013

Welcome to AntennaSelect Volume 1 August 2013 Welcome to AntennaSelect Volume 1 August 2013 This is the first issue of our new periodic newsletter, AntennaSelect. AntennaSelect will feature informative articles about antennas and antenna technology,

More information

SWR myths and mysteries.

SWR myths and mysteries. SWR myths and mysteries. By Andrew Barron ZL3DW September 2012 This article will explain some of the often misunderstood facts about antenna SWR at HF and uncover some popular misconceptions. The questions

More information

6M HALO VERSON II + OPTIONAL 2M GROUND PLANE

6M HALO VERSON II + OPTIONAL 2M GROUND PLANE The halo is an omnidirectional, horizontally polarized antenna with about the same gain as a dipole but without the low elevation nulls off the ends (+5.5 to +3.5dBi variation for the Halo vs. +7.9 to

More information

Antenna Theory and Design

Antenna Theory and Design Antenna Theory and Design Antenna Theory and Design Associate Professor: WANG Junjun 王珺珺 School of Electronic and Information Engineering, Beihang University F1025, New Main Building wangjunjun@buaa.edu.cn

More information

EZNEC Primer. Introduction:

EZNEC Primer. Introduction: EZNEC Primer Introduction: This document was written to cover the very basic functions of EZNEC. It's primarily geared to the use of EZNEC demo programs, specifically the Version 5 demo. While more elaborate

More information

TABLE OF CONTENTS Parallel Broadside Arrays Power Gain Directivity

TABLE OF CONTENTS Parallel Broadside Arrays Power Gain Directivity TABLE OF CONTENTS 12.1 Broadside Arrays 12.1.1 Collinear Arrays 12.1.2 Two-Element Arrays 12.1.3 Three- and Four-Element Arrays 12.1.4 Adjustment 12.1.5 The Extended Double Zepp 12.1.6 The Sterba Curtain

More information

ANTENNAS 101 An Introduction to Antennas for Ham Radio. Lee KD4RE

ANTENNAS 101 An Introduction to Antennas for Ham Radio. Lee KD4RE ANTENNAS 101 An Introduction to Antennas for Ham Radio Lee KD4RE Prepared for Presentation at the Vienna Wireless Society, 13 January 2017 So What is an Antenna Anyway? We are all familiar with wire antennas

More information

Some Observations on the K9AY Receive Directional Antenna

Some Observations on the K9AY Receive Directional Antenna Some Observations on the K9AY Receive Directional Antenna Tom McDermott, N5EG January 12, 2010 The K9AY antenna is a popular, compact receive directional antenna commonly used on the 80 and 160 meter amateur

More information

Ground-Mounted Verticals. Dispelling the Myths and Misconceptions

Ground-Mounted Verticals. Dispelling the Myths and Misconceptions Dispelling the Myths and Misconceptions Let s start with a quiz on vertical antennas and radials. Answers will be there to discover, as we proceed through the presentation. To be most effective, a ground-mounted

More information

Loop Antennas for HF Reception

Loop Antennas for HF Reception COMMUNICATIONS 74 CONFERENCE BRIGHTON Wednesday, June 5 1974 Session 5, Equipment Design Paper 5.3: Loop Antennas for HF Reception Contributed by: B.S.Collins, C & S Antennas Ltd., Knight Road, Rochester,

More information

Design of a Delta Loop September 26, 2016

Design of a Delta Loop September 26, 2016 Design of a Delta Loop September 26, 2016 by K0ZR Introduction Why a Delta loop? A Delta loop can be made to radiate a horizontal or vertically polarized signal. In most cases one chooses the vertical

More information

A Stub Matched Lazy H for 17 M

A Stub Matched Lazy H for 17 M A Stub Matched Lazy H for 17 M Introduction The author has experimented with various configurations of the classic Lazy H antenna and a version optimised for operation on the 17 M band is shown in Figure

More information

ANTENNA MATRIX. Antenna Matrix. Purpose. Using the Antenna Selection Proforma

ANTENNA MATRIX. Antenna Matrix. Purpose. Using the Antenna Selection Proforma Purpose The purpose of this Antenna Matrix is to assist you in deciding which antenna from Codan s range best suits your requirements for high frequency (HF) communication over the 2 30 MHz range. The

More information

WHY YOU NEED A CURRENT BALUN

WHY YOU NEED A CURRENT BALUN HF OPERATORS WHY YOU NEED A CURRENT BALUN by John White VA7JW NSARC HF Operators 1 What is a Balun? A BALUN is a device typically inserted at the feed point of a dipole-like antenna wire dipoles, Yagi

More information

Technician License Course Chapter 4. Lesson Plan Module 10 Practical Antennas

Technician License Course Chapter 4. Lesson Plan Module 10 Practical Antennas Technician License Course Chapter 4 Lesson Plan Module 10 Practical Antennas The Dipole Most basic antenna Total length is ½ wavelength (½ λ) Usual construction: Two equal halves of wire, rod, or tubing

More information

What is a BALUN or UNUN:

What is a BALUN or UNUN: What is a BALUN or UNUN: A device to connect different types of antennas to various feed lines. Can transform impedances, choke common mode or change balanced to unbalanced BALUN Balanced to Unbalanced

More information

A 6-Meter Quad-Turnstile

A 6-Meter Quad-Turnstile By L. B. Cebik, W4RNL A 6-Meter Quad-Turnstile Looking for improved omnidirectional, horizontally polarized performance? This 6-meter turnstile uses the quad loop as a foundation. Turnstile Principles

More information