General License Class Chapter 6 - Antennas. Bob KA9BHD Eric K9VIC
|
|
- Jessie Wilcox
- 5 years ago
- Views:
Transcription
1 General License Class Chapter 6 - Antennas Bob KA9BHD Eric K9VIC
2 Learning Objectives Teach you enough to get all the antenna questions right during the VE Session Learn a few things from you about antennas and your experiences Un-teach you a few things you might have picked up from friendly sources on the repeater Have fun (it s a hobby, right?) Finish before noon
3 VE Session Total of 4 questions from this chapter One each in these areas: Feedlines, Characteristic Impedance and Attenuation, SWR Calculation and Measurement and effects, Matching Networks Basic Antennas Directional Antennas Specialized Antennas
4 Feedlines Coax Twin Lead Ladder Line
5 Feedlines Coax For amateur use, 50 and 75 Ohm typical Impedance determined by size and spacing of conductors, and the type of dielectric Unbalanced Convenient Impedance matches most modern radios Physical routing easy Losses (db/100 ft.) increase with increased SWR and frequency
6 Feedlines Balanced Types Twin lead (300 Ohm) Ladder Line (~450 Ohm) Impedance determined by the distance between conductors, and the radius of the conductors Balanced Low loss even with high SWR Not always convenient Matching network usually required Physical installation can be tricky Not so good at VHF/UHF
7 Feedlines SWR (Standing Wave Ratio) Caused by reflection of RF at impedance mismatch Expressed as a ratio, always 1:1 or greater Cannot be eliminated by using a tuner at the radio end of the line Calculated by taking a ratio of impedances
8 Terminology Patterns Gain Front-to-Back Ratio Main Lobe Take-off Angle
9 Terminology Patterns Elevation What the radiation pattern would look like in the air from the side Varies from different side angles Azimuthal What the radiation pattern would look like if you could look down on it on the ground Varies at different elevations
10 Terminology Two Plots of the same antenna: Elevation Azimuth
11 Terminology Gain Comparative power Typically expressed in db Logarithmic power ratio db i, db d Only one aspect of performance to consider (not necessarily the only consideration)
12 Terminology Gain (where does it come from?)
13 Front-to-back ratio Terminology
14 Main Lobe Terminology
15 Take-off Angle Terminology
16 Terminology What s as important as gain figures? F/B Ratio Source (feedpoint) impedance Take-off angle (usually varies with height, not antenna design) Performance over what frequencies? Example
17 A Tale of Two Antennas
18 A Tale of Two Antennas Antenna A Antenna B Gain (db i ) F/B (db) Beam Width
19 A Tale of Two Antennas
20 A Tale of Two Antennas
21 Basic Antennas Random wire (not long wire) Ground plane (vertical monopole) Ground mounted vertical Dipole (vs. doublet)
22 Basic Antennas Random wire Advantages Cheap Can be put just about anywhere Disadvantages Radiation pattern unpredictable Requires remote match or leaves RF in the shack
23 Basic Antennas Random Length Wire
24 Basic Antennas Ground Plane Length roughly 234/f Omnidirectional pattern Characteristic impedance varies with radial angle (~35 Ohms with straight radials) Impedance Increases when bending radials (typically 4) downward
25 Ground Plane Basic Antennas
26 Basic Antennas Ground Plane What do the radials actually do? Are they passive? Do they radiate?
27 Basic Antennas Ground Plane showing currents
28 Ground Plane Basic Antennas
29 Basic Antennas Ground mounted vertical Requires radials (on or below ground) Radials ~1/4 wavelength, need not be tuned At least 16 or more radials for better performance Take-off angle relates to ground (not radial) type Some ground reflection loss due to vertical polarization
30 Basic Antennas Dipole Length roughly calculated as 468/f Free space impedance = 73 ohms when center fed Impedance increases if not center fed Real Life impedance from Ohms (goes down under ¼ wavelength)
31 Basic Antennas
32 Basic Antennas Dipole at 1/2 wavelength
33 Basic Antennas Dipole at wavelengths (NVIS)
34 (Uni) Directional Antennas Yagi-Uda Cubical Quad Delta Loop
35 Yagi-Uda Directional Antennas
36 Directional Antennas Yagi-Uda Driven element (DE) and some combination of Reflector and Director(s) Reflector slightly longer than the DE Driven Element about ½ Wavelength Director Shorter than the DE More Directors (on longer boom) = more gain DE impedance typically 35 Ohms Gamma match typically used to match 50 Ohm line
37 Directional Antennas Yagi-Uda Adjustments to boom length, number of elements, spacing of elements can be used to change: Gain (3-element has theoretical 9.7 db i ) F/B Ratio SWR Bandwidth Can also be increased with fatter elements
38 Directional Antennas Yagi-Uda Can be stacked Two 3-element Yagis ½ wavelength apart vertically increase gain by 3 db Elevation of major lobes gets tighter (lower overall elevation pattern)
39 Directional Antennas Yagi-Uda, Stacked pattern
40 Cubical Quad Directional Antennas
41 Directional Antennas Cubical Quad Driven Element (DE) and Reflector DE is about 1 Wavelength long Reflector is about 5% longer than the DE Spacing between elements is about 0.2 wavelengths Gain roughly the same as 3-element Yagi Feed at bottom or side
42 Delta Loop Directional Antennas
43 Directional Antennas Delta Loop Driven Element and Reflector (triangles) DE about 1 Wavelength long Reflector about 5% longer than the DE Gain about the same as the quad
44 Specialized Antennas Log Periodic Dipole Array (LPDA) Beverage Multiband Antennas
45 Specialized Antennas LPDA Logarithmic arrangement on boom Yagi-like gain Frequency range of 2:1, even 3:1 practical (theoretically, range could be infinite)
46 Specialized Antennas Beverage Antenna Several wavelengths of wire <0.05 wavelengths in height Terminated to ground through a resistor Directional For receive only due to ground losses (used on low HF bands)
47 Specialized Antennas Multiband Antennas Use traps/stubs to radiate on more than one band Trap is a tuned circuit At resonant frequency it presents high impedance Below resonant frequency it s typically inductive (makes antenna shorter)
48 Specialized Antennas Multiband Antennas Advantages More than one band with single feed line Disadvantages Low suppression of harmonics Can be higher maintenance Price
49 Case Study Not on the exam, but good practical knowledge. One reason it s good to have some knowledge of what we ve covered here this morning.
50 SWR as an Indicator Joe's been checking into the DARC 2- meter AM enthusiasts net on MHz using a 5/8 wavelength J-pole antenna. Someone asks him why he never checks in on 6-meters, and he says he doesn't have an antenna Joe's figures he'll try his 2-meter antenna on 6-meters
51 SWR as an Indicator Joe's antenna is (0.26 λ on 50.4 MHz) long (with matching section) Antenna is at 30 feet Antenna is fed with 75 feet Belden 9258 (RG-8X) Joe's antenna analyzer shows the impedance in the shack on 2-meters is 53 + j7 Ohms (SWR = 1.15:1)
52 SWR as an Indicator Joe measures the impedance in the shack at 50.4 MHz and finds that it's 14 +j23 Ohms (SWR = 4.4:1) Joe looks up loss data for his coax, and finds that 4.5:1 SWR will cause an additional 1.5 db loss Joe models his antenna and finds it has 4 dbi gain at 50.4 Joe runs 20 Watts on 6-meters; he calculates his ERP at 35.5 Watts (4 1.5 = 2.5 db gain)
53 SWR as an Indicator Joe puts a simple L-network (loss <<1dB) in his shack, and measures the SWR at 1:1 on 50.4 MHz. He calls and calls, but he can barely hear the net, and no one can hear him trying to check in. What happened to poor Joe?
54 SWR as an Indicator While at 50.4 MHz the SWR in the shack was 4.4:1, at the antenna it was 263:1 (impedance = 11.6 j440.6 Ohms) Line losses from SWR are 17 db Matched line loss is 2 db Total losses = 19 db
55 SWR as an Indicator Antenna pattern with and without feedline losses
56 SWR as an Indicator Reasonable SWR does not indicate your antenna is working well! Total power into the antenna = 0.2 Watts
57 SWR as an Indicator Mary has a dipole 65.5 long cut for the bottom of the FM broadcast band She knows the SWR at the antenna can't be measured with her SWR meter (>300:1) as the impedance is j542 Ohms She's determined to get on the 6-meter net
58 SWR as an Indicator Mary feeds her antenna with ladder line, and uses a tuner at the point it enters the house Mary's feedline loss is about 3 db, and tuner losses are negligible Mary's antenna has ~ 7 dbi gain at 50.4 MHz Total gain with feedline is about 4 dbi
59 SWR as an Indicator Antenna pattern with and without feedline losses
60 SWR as an Indicator Very High SWR does not indicate your antenna won't work well! Total power into the antenna = 9.1 Watts Difference from Joe's Antenna ~ 25 db
61 Questions? If you have any questions while reviewing the material or the CD, please me at: or See:
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 information4/29/2012. 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 informationAntennas 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 informationCHAPTER 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 informationChapter 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 informationGeneral 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 informationHalf-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 informationAntennas 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 informationLeast 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 informationComing 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 informationANTENNAS. 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 informationANTENNA 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 informationMilton 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 informationNewcomers 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 informationAntennas 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 informationYagi Antenna Tutorial. Copyright K7JLT 1
Yagi Antenna Tutorial Copyright K7JLT Yagi: The Man & Developments In the 920 s two Japanese electrical engineers, Hidetsugu Yagi and Shintaro Uda at Tohoku University in Sendai Japan, investigated ways
More informationANTENNAS 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 informationCray 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 informationBasic 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 informationTechnician 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 informationBeams 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 informationIntermediate Course (5) Antennas and Feeders
Intermediate Course (5) Antennas and Feeders 1 System Transmitter 50 Ohms Output Standing Wave Ratio Meter Antenna Matching Unit Feeder Antenna Receiver 2 Feeders Feeder types: Coaxial, Twin Conductors
More informationChapter 9 Antennas and Feedlines
Chapter 9 Antennas and Feedlines Basics of Antennas Antenna Radiation Patterns. Graphical representation of spatial distribution of energy around an antenna. 3D = Full representation. 2D = Slice through
More informationTraveling 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 information4 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 informationLast 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 informationThe 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 information1) 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 informationAntenna 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 informationAmateur Radio License. Propagation and Antennas
Amateur Radio License Propagation and Antennas Todays Topics Propagation Antennas Propagation Modes Ground wave Low HF and below, ground acts as waveguide Line-of-Sight (LOS) VHF and above, radio waves
More information4/25/2012. 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 informationFundamentals of Antennas. Prof. Ely Levine
Fundamentals of Antennas Prof. Ely Levine levineel@zahav.net.il 1 Chapter 3 Wire Antennas 2 Types of Antennas 3 Isotropic Antenna Isotropic radiator is the simplest antenna mathematically Radiates all
More informationYagi 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 informationL. 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).
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
More informationAntenna Fundamentals Basics antenna theory and concepts
Antenna Fundamentals Basics antenna theory and concepts M. Haridim Brno University of Technology, Brno February 2017 1 Topics What is antenna Antenna types Antenna parameters: radiation pattern, directivity,
More informationLesson 11: Antennas. Copyright Winters Version 1.0. Preparation for Amateur Radio Technician Class Exam
Lesson 11: Antennas Preparation for Amateur Radio Technician Class Exam Topics Antenna ½ wave Dipole antenna ¼ wave Vertical antenna Antenna polarization Antenna location Beam antennas Test Equipment Exam
More informationANTENNAS 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 informationDevelopment 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 informationTechnician 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 informationThe 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 informationCOAXIAL TRANSMISSION LINE COMMON-MODE CURRENT
COAXIAL TRANSMISSION LINE COMMON-MODE CURRENT Introduction Coaxial transmission lines are popular for their wide frequency bandwidth and high resistance to electromagnetic interference (EMI). Coax cables
More informationEMG4066: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 informationDO 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 informationTechnician Licensing Class. Lesson 4. presented by the Arlington Radio Public Service Club Arlington County, Virginia
Technician Licensing Class Lesson 4 presented by the Arlington Radio Public Service Club Arlington County, Virginia 1 Quiz Sub elements T6 & T7 2 Good Engineering Practice Sub element T8 3 A Basic Station
More informationEmergency Antennas. Presented by Ham Hilliard W4GMM
Emergency Antennas Presented by Ham Hilliard W4GMM Dipole antenna Vertical antenna Random wire antenna Dipole antenna The half wave dipole antenna consists of a conductive wire or rod that is half the
More informationTechnician 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 informationAntenna Trainer EAN. Technical Teaching Equipment INTRODUCTION
Antenna Trainer EAN Technical Teaching Equipment Products Products range Units 3.-Communications INTRODUCTION Antennas are the main element of aerial communications. They are the transition between a transmission
More informationOther 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 informationThe 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 informationThe Multiband Tuned Doublet Antenna
Editors Note: This article first appeared in the December 1999 issue of The Reflector. The Editors thought it might be useful to the many newly-licensed radio amateurs who have joined our ranks to reprint
More informationTechnician 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 informationANOTHER MULTIBAND WIRE ANTENNA
ANOTHER MULTIBAND WIRE ANTENNA Above The multiband long wire with balun (cover is off) by Ron VK3AFW. I wanted to build a simple wire antenna dedicated to 30 m and 17m for operation during the 2015 ILLW
More informationCHAPTER 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 informationChapter 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 informationResonant Antennas: Wires and Patches
Resonant Antennas: Wires and Patches Dipole Antennas Antenna 48 Current distribution approximation Un-normalized pattern: and Antenna 49 Radiating power: For half-wave dipole and,, or at exact resonance.
More informationFCC 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 informationstacking 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 informationOptimizing Your Stations Performance
Optimizing Your Stations Performance A few hints / techniques, recommendations for getting the most RF out to the Antenna from your HF, VHF / UHF station. Tonights Presenters: Doug Theriault NO1D John
More informationANTENNA DESIGN FOR FREE USING MMANA-GAL SOFTWARE
ANTENNA DESIGN FOR FREE USING MMANA-GAL SOFTWARE 1. AVAILABLE ANTENNA DESIGN SOFTWARE EZNEC and 4nec2 are based upon the Numerical Electromagnetics Code, or NEC, which is a popular antenna modelling system
More informationWeekend 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 informationImproved 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 informationOne 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 informationANTENNA 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 informationFeed 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 informationInstall as much wire/tubing as possible Electrically short antennas Minimize matching losses Good ground for verticals Maximizes antenna efficiency
Jim Wolf KR9U Install as much wire/tubing as possible Electrically short antennas Minimize matching losses Good ground for verticals Maximizes antenna efficiency Far-away ground conditions determine low
More informationThe 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 informationWCARES NEEDS YOU! CONSIDER MAKING A TECHNICAL PRESENTATION AT AN UPCOMING CHEW & CHAT MEETING LEARN SOMETHING NEW AND PRESENT
WCARES NEEDS YOU! CONSIDER MAKING A TECHNICAL PRESENTATION AT AN UPCOMING CHEW & CHAT MEETING SHARE WHAT YOU KNOW LEARN SOMETHING NEW AND PRESENT IT CONTACT TIM AD4CJ AD4CJ@arrl.net 1 Transmission Line
More informationA 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 informationSCARS Technician / General License Course Week 4
SCARS Technician / General License Course Week 4 Radio Wave Propagation: Getting from Point A to Point B Radio waves propagatein many ways depending on Frequency of the wave Characteristics of the environment
More informationA 2 ELEMENT 30 METER PARASITIC VERTICAL ARRAY PROJECT
A 2 ELEMENT 30 METER PARASITIC VERTICAL ARRAY PROJECT Having killed off the 5B-DXCC purely using LOTW, it was time for the addition of a new band. 30 meters was selected based on lack of sunspots and a
More informationWorking Bouvet with the Innovative and Cheap N6MW, Bill Wortman
Working Bouvet with the Innovative and Cheap N6MW, Bill Wortman Trying to work the upcoming early 2018 Bouvet Dxpedition for an all time new one (ATNO as we say) is a serious challenge for those with only
More informationMFJ-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 informationComparative Analysis of Quagi and Yagi-Uda Antenna using 4NEC2 Tool
Comparative Analysis of Quagi and Yagi-Uda Antenna using 4NEC2 Tool Vinaykumar V.Angadi Student, Electronics and Communication Engineering, SKSVMACET, Lakshmeshwar. angadivinay19@gmail.com Abstract- A
More informationGround-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 informationEZNEC 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 informationThe DBJ-1: A VHF-UHF Dual-Band J-Pole
By Edison Fong, WB6IQN The DBJ-1: A VHF-UHF Dual-Band J-Pole Searching for an inexpensive, high-performance dual-band base antenna for VHF and UHF? Build a simple antenna that uses a single feed line for
More informationImpedance, Reflections, and Transformations
Impedance, Reflections, and Transformations Rocky Mountain Ham Radio University Chris Hamilton AE5IT 2017 December 16 Conventional wisdom: My antenna is useless above 1.5:1 SWR (Or is it 2:1? Or 3:1?)
More informationAntenna 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 informationCoupling the Line to the Antenna
Chapter 26 Coupling the Line to the Antenna Chapter 25, Coupling the Transmitter to the Line, looked at system design from the point of view of the transmitter, examining what could be done to ensure that
More informationL. 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 informationTransforms 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 informationThe J-Pole Antenna. Gary Wescom
The J-Pole Antenna Gary Wescom - 2018 Much has been written about the J-Pole antenna. A simple Google search will net days worth of reading material on the subject. That would tend to indicate this paper
More informationMultiband Vertical Antenna Project 2004 by Harold Melton, KV5R
2004 by Harold Melton, KV5R Page 1 of 5 Printed 1/14/2004 05:02:00 PM Multiband Vertical Antenna Project 2004 by Harold Melton, KV5R Purpose If you could only have two antennas, what would they be? It
More informationJ-Poles. Mythbusting J-Pole Antennas
Mythbusting J-Pole Antennas For an antenna to work correctly, it must do two things well 1) Accept power from the feed line impedance match, SWR (ideally) 1:1 2) Radiate power in a pattern that is useful
More informationInexpensive Lightweight High-Performance Small Yagi Antennas for VHF-UHF Portable Operation
Inexpensive Lightweight High-Performance Small Yagi Antennas for VHF-UHF Portable Operation Rick Campbell KK7B Pacific Northwest VHF Conference Bend, Oregon October 8 2016 But why? We already have: Inexpensive
More informationBroadband 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 informationTable 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 informationA Tri Band Antenna for 2 meters, 220 MHz, and 70cm Antenna Without Radials. By: Edison Fong (WB6IQN)
A Tri Band Antenna for 2 meters, 220 MHz, and 70cm Antenna Without Radials By: Edison Fong (WB6IQN) Twenty years ago a single band handie talkie would have been adequate for emergency use since almost
More informationMiscellaneous Topics. Folded dipole antenna Special antennas. Other antennas Feed Lines. Yagi-Uda antenna Broadband antenna Log-periodic antenna
Folded dipole antenna Special antennas Yagi-Uda antenna Broadband antenna Log-periodic antenna Other antennas Feed Lines Miscellaneous Topics 1 Folded Dipole Half-wavelength dipoles have impedance 73+j42.5
More informationThe Vertical Buddi Beam on 20m using no Coils.
The Vertical Buddi Beam on 20m using no Coils. design by Lou Rummel KE4UYP In this article I am going to describe a totally new way to construct and use a very old design the two element Yagi antenna.
More informationTWO METER HOMEMADE SLIM JIM ANTENNA
Gordon Gibby July 15, 2016 TWO METER HOMEMADE SLIM JIM ANTENNA WIRE: Start with a piece of solid #14 AWG household wire approximately 3 yards and 9 inches long (117 ) (It is easier to be a couple inches
More informationA 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 informationAugust, Antennas 101: A Course in RF Basics
August, 2012 Antennas 101: A Course in RF Basics Antenna Basics Agenda: In today s training, we will go over a brief summary of the following topics at a basic level: Electromagnetic Waves Frequency and
More informationAmateur 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 informationSI TECHNICAL 2018 UNIT IV QUESTION BANK
SI TECHNICAL 2018 UNIT IV QUESTION BANK 1. In what range of frequencies are most omnidirectional horizontally polarized antennas used? A. VHF, UHF B. VLF, LF C. SH, EHF D. MF, HF 2. If the current ratios
More informationLow 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 informationM2 Antenna Systems, Inc. Model No: 2M HO LOOP
M2 Antenna Systems, Inc. Model No: 2M HO LOOP SPECIFICATIONS: Model... 2M HO LOOP Frequency Range... 144 To 144.5 MHz Gain, Typical @ 10 ft.... 4 dbd @ 10 deg. Gain, 2 STK @ 82 & 132... 8 dbd @ 9 deg.
More informationUNIT 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 informationSWR 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 informationAntenna Systems for the Recently Licensed Ham --3 Talks-- BVARC Meeting May 10 th, 2012
Antenna Systems for the Recently Licensed Ham --3 Talks-- BVARC Meeting May 10 th, 2012 Understanding the Cardinal Rules of the Ham Radio Antenna System Rick Hiller -- W5RH Utilizing Your New Found Practical
More information