AN INTRODUCTION TO VHF/ UHF PROPAGATION. Paul Wilton, M1CNK
|
|
- Laurel Boone
- 6 years ago
- Views:
Transcription
1 AN INTRODUCTION TO VHF/ UHF PROPAGATION Paul Wilton, M1CNK
2 OVERVIEW Introduction Propagation Basics Propagation Modes Getting Started in 2m DX
3 INTRODUCTION QRV on 2m SSB since Aug 1998, on 6m since Jan 2001 and 70cm since Mar m:12 ele ZL-Special - 100W 6m: 3 ele beam - 60W 70cm: 8 over 8 beam - 50w Yaesu FT-726
4 PROPAGATION BASICS Radio Waves travel in straight lines in free space. Direction can only be changed through either reflection, refraction or diffraction. For VHF/UHF, other mechanisms other than ionosphere are important.
5 PROPAGATION BASICS
6 PROPAGATION MODES Mode 6m 2m 70cm Line of Sight F2-layer TEP/FAI Sporadic E Meteor Scatter Auroral Scatter Tropospheric Refraction Tropospheric Scatter
7 LINE OF SIGHT As title suggests, radio line of sight required between stations. Because of atmospheric refraction, the radio horizon equals radius of curvature of earth plus a third. Multi-path propagation dominates in the real world. Height above local environment is very important. 6m 2m 70cm
8
9 F2-PROPAGATION Continuation of HF F2-layer propagation to 6m band. Occurs when the the Maximum Usable Frequency high enough to allow propagation at 6m. Can give world wide communications. 6m
10 TEP/FAI TEP Trans Equatorial Propagation Specialised form of F2 propagation Allows N/S paths across the Equator On 6m, allows regular contacts to Southern Africa from Southern Europe FAI Field Aligned Irregularities Rare scattering mode caused by ionospheric electrons trapped by Earth s magnetic field 6m 2m
11 SPORADIC-E Occurs in the summer months when small clouds of electrons form in the E layer. Produces spectacularly strong signals. Occurs on 10m, 6m and 2m. Open most afternoons on 6m between May and August. Can occur in December as well. As the cloud moves, geographic areas can rapidly change especially on 2m. 6m 2m
12 SPORADIC-E Cause not known but a number of theories have been put forward. Most likely cause is wind sheer. Multi-hop possible to extend range. Distances from 500km to 8,000km on 6m. Distances from 800km to nearly 4,000km on 2m. 6m 2m
13 METEOR SCATTER Uses reflections from the trails of ionisation left behind by meteors as they burn up in the atmosphere at a height of between 88km to 100km Reflections are short lived so either high speed CW or computer modes needed on 2m. Random Meteors occur at all times. Seasonal showers also occur, during some of these, SSB can be used. 6m 2m 70cm
14 METEOR SCATTER Originally high Speed CW was used, produced by a computer and recorded at the receiver by either a special tape recorder or by a computer. The received data was then played back at much slower speed to be decoded by ear. However, has been replaced by FSK441mode - part of WJST by K1JT, Joe Taylor 6m 2m 70cm
15 METEOR SCATTER Distances of between 1000km and 2000km can be obtained with modest stations called the poor man s DX. On 6m, reflection time is longer so SSB is can be used. Meteor Scatter is used commercially on frequencies around 6m. 6m 2m 70cm
16 AURORAL SCATTER Uses scattering from the cloud of ionisation produced by an aurora (Northern Lights). Favours northerly stations, although during more severe geomagnetic storms, the aurora can move south. More likely to occur near sun-spot maxima and around the equinox. 6m 2m 70cm
17 AURORAL SCATTER Antennas need to be pointed North for both stations. CW is generally used owing to the immense distortion introduced. Auroral CW Auroral SSB over a 560mile path between VE3SQD and WA1VRH 6m 2m 70cm
18 AURORAL SCATTER Distortion caused by Doppler shift of the frequency and hence get worse as frequency increases. 6m easier than 2m which is easier than 70cm. Ranges of between 500km and 2000km possible on 2m. 6m 2m 70cm
19 TROPOSPHERIC REFRACTION Also call lift or ducting. Most commonly seen enhancement. Caused by the changes in the speed of radio waves due to variations in air temperature and pressure refraction. Stable high pressure weather systems good indicator. 6m 2m 70cm
20 TROPOSPHERIC REFRACTION Enhanced refraction occurs when the rate of change of refraction is far larger than normal enhances the standard radio horizon beyond standard curvature plus a third. Ducting occurs when there is an inversion taking place either at ground level or at an elevation. 6m 2m 70cm
21 TROPOSPHERIC REFRACTION
22 TROPOSPHERIC REFRACTION Ducts can allow immense distances to be obtained especially over sea paths. Inversions are most common with high pressure anti-cyclones. 70cm can often be better than 2m owing to the smaller wavelength. 6m 2m 70cm
23 TROPOSPHERIC REFRACTION Text
24 TROPOSPHERIC SCATTER The Workhorse of DX under flat conditions available all year round. Uses scattering from turbulence in the troposphere. Allows distances of up to about 500km between suitable equipped stations. The lower the angle of take-off, the longer the range. 6m 2m 70cm
25 TROPOSPHERIC SCATTER For each 1 increase in take-off angle, there is a 9-12dB cut in signal strength - 1½ to 2 S-points! Take-off angle impacted by: Local obstructions Antenna height above ground - eg 10m on 144MHz is 3 take-off but 9 on 50MHz. 20m on 144MHz is 1.5 take-off Can use sloping ground to replace antenna height. 6m 2m 70cm
26 M1CNK 6M
27 M1CNK 6M
28 M1CNK 2M
29 M1CNK 70CM
30 GETTING STARTED IN 2M DX Basics Multimode 2m rig needs SSB or CW. Beam antenna plus rotator. Situations Clear take-off essential in direction of interest. Low-angle radiation requires beam to be elevated (ideally 10x wavelength) or at the top of a hill with sloping ground.
31 GETTING STARTED IN 2M DX Enhancements Low loss coax feed RG213 or better. Mast head pre-amp with minimum amount of gain to improve RX sensitivity/overcome coax loss. Power amp 100w or more.
32 OPERATING AIDS Beacons maps from DX Clusters alerts from DX Clusters Hepburn Tropo Index alerts from UK magentometers
33 ANY QUESTIONS?
Topics in Propagation
Topics in Propagation Extra Class Course Spring 2013 Andy Durbin k3wyc Propagation The magic that allows a signal to travel between the transmitting antenna and the receiving antenna. This course is limited
More information1. Terrestrial propagation
Rec. ITU-R P.844-1 1 RECOMMENDATION ITU-R P.844-1 * IONOSPHERIC FACTORS AFFECTING FREQUENCY SHARING IN THE VHF AND UHF BANDS (30 MHz-3 GHz) (Question ITU-R 218/3) (1992-1994) Rec. ITU-R PI.844-1 The ITU
More informationRadio Propagation - VHF and higher
Radio Propagation - VHF and higher (Without the Mathematics) Presented by Dr John Worsnop G4BAO RSGB Propagation Studies Committee RadCom GHz bands Columnist With a little help from http://www.mike-willis.com/tutorial/propagation.html
More informationTechnician License Course Chapter 4
Technician License Course Chapter 4 Propagation, Basic Antennas, Feed lines & SWR K0NK 26 Jan 18 The Antenna System Antenna: Facilitates the sending of your signal to some distant station. Feed line: Connects
More informationVHF/UHF Beyond FM Bob Witte KØNR Page 1
VHF/UHF Beyond FM Technical Coordinator Colorado Section Page 1 Objective The objective of this presentation is to provide an introduction to operating on VHF/UHF, going beyond the usual FM / Repeater
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 informationLesson 12: Signal Propagation
Lesson 12: Signal Propagation Preparation for Amateur Radio Technician Class Exam Topics HF Propagation Ground-wave Sky-wave Ionospheric regions VHF/UHF Propagation Line-of-sight Tropospheric Bending and
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 informationVHF Propagation Overview 5-Oct-2016
VHF Propagation Overview 5-Oct-2016 G0RVM 1 VHF Propagation Where in the radio spectrum is VHF? 30MHz to 300MHz for radio amateurs its 50MHz, 70MHz & 144MHz or 6m, 4m & 2m Name some types of VHF propagation?
More informationright during the VE Session Have fun Bob, KA9BH Eric, K9VIC
Radio Wave Propagation Teach you enough to get all right during the VE Session Learn a few things from you Have fun Finish everything on time (if the propagation questions about your experiences not a
More information4/18/2012. Supplement T3. 3 Exam Questions, 3 Groups. Amateur Radio Technician Class
Amateur Radio Technician Class Element 2 Course Presentation ti ELEMENT 2 SUB-ELEMENTS Technician Licensing Class Supplement T3 Radio Wave Characteristics 3 Exam Questions, 3 Groups T1 - FCC Rules, descriptions
More informationChapter 6 Propagation
Chapter 6 Propagation Al Penney VO1NO Objectives To become familiar with: Classification of waves wrt propagation; Factors that affect radio wave propagation; and Propagation characteristics of Amateur
More informationChapter 7 HF Propagation. Ionosphere Solar Effects Scatter and NVIS
Chapter 7 HF Propagation Ionosphere Solar Effects Scatter and NVIS Ionosphere and Layers Radio Waves Bent by the Ionosphere Daily variation of Ionosphere Layers Ionospheric Reflection Conduction by electrons
More information4/29/2012. General Class Element 3 Course Presentation. Radio Wave Propagation. Radio Wave Propagation. Radio Wave Propagation.
General Class Element 3 Course Presentation ti ELEMENT 3 SUB ELEMENTS General Licensing Class Subelement G3 3 Exam Questions, 3 Groups G1 Commission s Rules G2 Operating Procedures G3 G4 Amateur Radio
More informationSw earth Dw Direct wave GRw Ground reflected wave Sw Surface wave
WAVE PROPAGATION By Marcel H. De Canck, ON5AU Electromagnetic radio waves can propagate in three different ways between the transmitter and the receiver. 1- Ground waves 2- Troposphere waves 3- Sky waves
More informationUNIT Derive the fundamental equation for free space propagation?
UNIT 8 1. Derive the fundamental equation for free space propagation? Fundamental Equation for Free Space Propagation Consider the transmitter power (P t ) radiated uniformly in all the directions (isotropic),
More informationAircraft Scatter on 10 and 24 GHz using JT65c and ISCAT-A
Aircraft Scatter on 10 and 24 GHz using JT65c and ISCAT-A By VK7MO and David Smith VK3HZ The authors have been using the digital modes JT65C and ISCAT-A to work aircraft scatter at distances of up to 842
More informationRF Propagation. By Tim Kuhlman, PE KD7RUS
RF Propagation By Tim Kuhlman, PE KD7RUS Purpose of this Seminar In this seminar we will attempt to answer the following questions: What is RF propagation? What are the different types of propagation?
More informationIonospheric Propagation
Ionospheric Nick Massey VA7NRM 1 Electromagnetic Spectrum Radio Waves are a form of Electromagnetic Radiation Visible Light is also a form of Electromagnetic Radiation Radio Waves behave a lot like light
More informationRadio Frequency Propagation: A General Overview from LF to VHF.
Radio Frequency Propagation: A General Overview from LF to VHF. Presented by: Mike Parkin GØJMI Slide 1 Introduction Mike Parkin: First licensed as G8NDJ in 1977. Became GØJMI in 1988. Interests in Radio
More informationAmateur Microwave Communications. Ray Perrin VE3FN, VY0AAA April 2010
Amateur Microwave Communications Ray Perrin VE3FN, VY0AAA April 2010 Introduction Microwaves are the frequencies above 1000 MHz More than 99% of the radio amateur frequency allocation is in the microwave
More informationTransequatorial VHF-UHF Propagation
Transequatorial VHF-UHF Propagation the next challenges for VK Roger Harrison VK2ZRH GippsTech Conference 2007 Churchill, Victoria Australia 1 A Rayleigh-Taylor production There are holes in the sky Where
More informationRF Propagation. By Tim Kuhlman, PE KD7RUS
RF Propagation By Tim Kuhlman, PE KD7RUS Purpose of this Seminar In this seminar we will attempt to answer the following questions: What is RF propagation? What are the different types of propagation?
More informationRADIO WAVES PROPAGATION
RADIO WAVES PROPAGATION Definition Radio waves propagation is a term used to explain how radio waves behave when they are transmitted, or are propagated from one point on the Earth to another. Radio Waves
More information6M DX ING Jason Timmis, VE7AG. Why, What, Where, When and How.
6M DX ING Jason Timmis, VE7AG Why, What, Where, When and How. WHY? Intrigue of doing something rare; witnessing the mystique of propagation Playing with Mother Earth and winning Because it s not 20M s!!
More informationRadio Communication. Presentation created by: András Balogh
Radio Communication Presentation created by: András Balogh AM and FM The goal is to transmit a modulating signal S(t) via a wave sin(ωt). In case of AM, the product of the modulation is f(t)=(a+s(t))*sin(ωt);
More informationSpace Weather and Propagation JANUARY 14, 2017
Space Weather and Propagation MARTIN BUEHRING -KB4MG ELEC T R ICAL ENGINEER, A M AT EUR EXTRA CLASS LICENSE HOLDER JANUARY 14, 2017 Why know about Space Weather? Our SUN has an enormous affect not only
More informationVHF and Microwave Propagation Characteristics of Ducts
1 VHF and Microwave Propagation Characteristics of s Andrew L. Martin, VK3KAQ Abstract Measurements from many years of amateur radio observations together with commercial microwave propagation studies
More informationRADIO WAVE PROPAGATION
CHAPTER 2 RADIO WAVE PROPAGATION Radio direction finding (RDF) deals with the direction of arrival of radio waves. Therefore, it is necessary to understand the basic principles involved in the propagation
More informationCHAPTER 6. Propagation
CHAPTER 6 Propagation TOC: INTRO RADIO WAVES POLARIZATION LINE OF SIGHT, GROUND & SKY WAVES IONOSPHERE REGIONS IONOSPHERIC LAYERS PROPAGATION, HOPS, SKIPS ZONES ABSORPTION AND FADING SOLAR ACTIVITY AND
More informationRadar Reprinted from "Waves in Motion", McGourty and Rideout, RET 2005
Radar Reprinted from "Waves in Motion", McGourty and Rideout, RET 2005 What is Radar? RADAR (Radio Detection And Ranging) is a way to detect and study far off targets by transmitting a radio pulse in the
More informationSpace Weather and the Ionosphere
Dynamic Positioning Conference October 17-18, 2000 Sensors Space Weather and the Ionosphere Grant Marshall Trimble Navigation, Inc. Note: Use the Page Down key to view this presentation correctly Space
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 informationDartmouth College SuperDARN Radars
Dartmouth College SuperDARN Radars Under the guidance of Thayer School professor Simon Shepherd, a pair of backscatter radars were constructed in the desert of central Oregon over the Summer and Fall of
More informationUpper Level Lows and Six Meter 50 Mhz Es: A Citizen Science Investigation
K1YOW Upper Level Lows and Six Meter 50 Mhz Es: A Citizen Science Investigation Joseph A. Dzekevich, K1YOW@ARRL.NET Presented by Phil Erickson, W1PJE@ARRL.NET Outline I. Introduction II. What Started This
More information3 Methods of radiocommunication
+ + & & * * ) ) From the ITU Emergency Telecommunications handbook; prepared for the 54 th JOTA 2011. 3 Methods of radiocommunication 3.1 Frequencies Radio frequencies should be selected according to propagation
More information255 km Aircraft Scatter QSO on 24 GHz
255 km Aircraft Scatter QSO on 24 GHz First crossing of Bass Strait on 24 GHz By Rex Moncur VK7MO and David Smith VK3HZ On 13 March 2012, VK3HZ at Mt Liptrap near Wilson s Promontory in Victoria worked
More informationOBJECTIVES: PROPAGATION INTRO RADIO WAVES POLARIZATION LINE OF SIGHT, GROUND WAVE, SKY WAVE IONOSPHERE REGIONS PROPAGATION, HOPS, SKIPS ZONES THE
WAVE PROPAGATION OBJECTIVES: PROPAGATION INTRO RADIO WAVES POLARIZATION LINE OF SIGHT, GROUND WAVE, SKY WAVE IONOSPHERE REGIONS PROPAGATION, HOPS, SKIPS ZONES THE IONOSPHERIC LAYERS ABSORPTION AND FADING
More informationIntroduction to HF Propagation. Rick Fletcher, W7YP FVARC November 20, 2018
Introduction to HF Propagation Rick Fletcher, W7YP FVARC November 20, 2018 Topics The HF Bands How HF propagation works Overview by HF band Sources of solar and propagation information Working HF during
More informationThe Basics of VHF and UHF Signal Propagation
The Basics of VHF and UHF Signal Propagation The Electromagnetic Spectrum - The electromagnetic spectrum is a continuum of all electromagnetic waves arranged according to frequency and wavelength. Electromagnetic
More informationReading 28 PROPAGATION THE IONOSPHERE
Reading 28 Ron Bertrand VK2DQ http://www.radioelectronicschool.com PROPAGATION THE IONOSPHERE The ionosphere is a region of the upper atmosphere extending from a height of about 60 km to greater than 500
More informationChapter 1 Introduction
Wireless Information Transmission System Lab. Chapter 1 Introduction National Sun Yat-sen University Table of Contents Elements of a Digital Communication System Communication Channels and Their Wire-line
More informationGeneral Classs Chapter 7
General Classs Chapter 7 Radio Wave Propagation Bob KA9BHD Eric K9VIC Learning Objectives Teach you enough to get all the propagation questions right during the VE Session Learn a few things from you about
More informationCurrent Solar Cycle Poor propagation No propagation Checking HF propagation. Coping with poor HF propagation Q&A
Topics Current Solar Cycle Poor propagation No propagation Checking HF propagation Predictive (HF propagation prediction software) Empirical (beacons, WSPR, PSKREPORTER and operator testing) Coping with
More informationChapter 4. Propagation, Antennas and Feed Lines. Propagation Black magic topic #1. How do radio waves get from point A to point B?
Chapter 4 Propagation, Antennas and Feed Lines Propagation Black magic topic #1. How do radio waves get from point A to point B? 1 Radio Wave Propagation Normally radio waves travel in a straight line,
More informationGlobal Maps with Contoured Ionosphere Properties Some F-Layer Anomalies Revealed By Marcel H. De Canck, ON5AU. E Layer Critical Frequencies Maps
Global Maps with Contoured Ionosphere Properties Some F-Layer Anomalies Revealed By Marcel H. De Canck, ON5AU In this column, I shall handle some possibilities given by PROPLAB-PRO to have information
More information# DEFINITIONS TERMS. 2) Electrical energy that has escaped into free space. Electromagnetic wave
CHAPTER 14 ELECTROMAGNETIC WAVE PROPAGATION # DEFINITIONS TERMS 1) Propagation of electromagnetic waves often called radio-frequency (RF) propagation or simply radio propagation. Free-space 2) Electrical
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 informationTerrain Reflection and Diffraction, Part One
Terrain Reflection and Diffraction, Part One 1 UHF and VHF paths near the ground 2 Propagation over a plane Earth 3 Fresnel zones Levis, Johnson, Teixeira (ESL/OSU) Radiowave Propagation August 17, 2018
More informationWEATHER - RELATED INTERFERENCE
WEATHER - RELATED INTERFERENCE Many people are familiar with the interference to TV and FM Radio reception that can occur during abnormal weather conditions. Doesn't it always seem to happen in the middle
More informationPolarization orientation of the electric field vector with respect to the earth s surface (ground).
Free space propagation of electromagnetic waves is often called radio-frequency (rf) propagation or simply radio propagation. The earth s atmosphere, as medium introduces losses and impairments to the
More informationChapter 15: Radio-Wave Propagation
Chapter 15: Radio-Wave Propagation MULTIPLE CHOICE 1. Radio waves were first predicted mathematically by: a. Armstrong c. Maxwell b. Hertz d. Marconi 2. Radio waves were first demonstrated experimentally
More informationIf maximum electron density in a layer is less than n', the wave will penetrate the layer
UNIT-7 1. Briefly the describe the terms related to the sky wave propagation: virtual heights, critical frequency, maximum usable frequency, skip distance and fading? Ans: Sky wave propagation: It is also
More informationS.R.M. Institute of Science & Technology Deemed University School of Electronics & Communication Engineering
S.R.M. Institute of Science & Technology Deemed University School of Electronics & Communication Engineering Question Bank Subject Code : EC401 Subject Name : Antennas and Wave Propagation Year & Sem :
More informationPART 1 RECOMMENDATION ITU-R P.1144 GUIDE TO THE APPLICATION OF THE PROPAGATION METHODS OF RADIOCOMMUNICATION STUDY GROUP 3
Rec. ITU-R P.1144 1 PART 1 SECTION P-A: TEXTS OF GENERAL INTEREST Rec. ITU-R P.1144 RECOMMENDATION ITU-R P.1144 GUIDE TO THE APPLICATION OF THE PROPAGATION METHODS OF RADIOCOMMUNICATION STUDY GROUP 3 (1995)
More informationRegional and Long Distance Skywave Communications
Regional and Long Distance Skywave Communications F LAYER SKYWAVE ELEVATION ANGLE STATION - A STATION - B Ken Larson KJ6RZ October 2010 1 Page Title 3 1.0 Introduction 3 2.0 The Earth s Ionosphere 6 3.0
More informationRadar Systems Engineering Lecture 5 Propagation through the Atmosphere
Radar Systems Engineering Lecture 5 Propagation through the Atmosphere Dr. Robert M. O Donnell Guest Lecturer Radar Systems Course 1 Block Diagram of Radar System Target Radar Cross Section Propagation
More informationAmateur Radio Service Technician Class
Amateur Radio Service Technician Class Exam Preparation Class January 2019 Session 2 Roland K. Smith K7OJL Phone: (435) 849-1946 Email: rolandksmith@gmail.com 1 TechClass-Session2.key - January 11, 2019
More informationAdaptive Reception of Dual Polarity EME Signals Using Linrad. By Ed Cole KL7UW
Adaptive Reception of Dual Polarity EME Signals Using Linrad By Ed Cole KL7UW Introduction This paper explores receiving eme signals in two polarities simultaneously, and using the Linrad (Linux radio)
More informationPoint to point Radiocommunication
Point to point Radiocommunication SMS4DC training seminar 7 November 1 December 006 1 Technical overview Content SMS4DC Software link calculation Exercise 1 Point-to-point Radiocommunication Link A Radio
More informationTRANSEQUATORIAL RADIO PROPAGATION
TRANSEQUATORIAL RADIO PROPAGATION 1 Introduction Most ionospheric models consider the ionosphere as a series of horizontal layers that vary only slowly with time and geographical location. Propagation
More informationTABLE OF CONTENTS. 4.4 Propagation Prediction Software Solar Activity Data. 4.5 Bibliography. Antenna Fundamentals 1-1
TABLE OF CONTENTS 4.1 The Nature of Radio Waves 4.1.1 Bending of Radio Waves 4.1.2 Ground Waves 4.1.3 The Surface Wave 4.1.4 The Space Wave 4.1.5 VHF/UHF Propagation Beyond Line of Sight 4.1.6 Antenna
More informationMaximum Usable Frequency
Maximum Usable Frequency 15 Frequency (MHz) 10 5 0 Maximum Usable Frequency Usable Frequency Window Lowest Usable Frequency Solar Flare 6 12 18 24 Time (Hours) Radio Blackout Usable Frequency Window Ken
More informationTHE NATURE OF GROUND CLUTTER AFFECTING RADAR PERFORMANCE MOHAMMED J. AL SUMIADAEE
International Journal of Electronics, Communication & Instrumentation Engineering Research and Development (IJECIERD) ISSN(P): 2249-684X; ISSN(E): 2249-7951 Vol. 6, Issue 2, Apr 2016, 7-14 TJPRC Pvt. Ltd.
More information14. COMMUNICATION SYSTEM
14. COMMUNICATION SYSTEM SYNOPSIS : INTRODUCTION 1. The exchange of information between a sender and receiver is called communication. 2. The arrangement of devices to transfere the information is called
More information1. What are the applications of loop antenna? (May2011) 2. Define Pattern Multiplication (May2011)
UNIT-II WIRE ANTENNAS AND ANTENNA ARRAYS 1. What are the applications of loop antenna? (May2011) 2. Define Pattern Multiplication (May2011) 3. A uniform linear array contains 50 isotropic radiation with
More informationHigh Frequency Propagation (and a little about NVIS)
High Frequency Propagation (and a little about NVIS) Tom McDermott, N5EG August 18, 2010 September 2, 2010 Updated: February 7, 2013 The problem Radio waves, like light waves, travel in ~straight lines.
More informationRadiation and Particles from the. Sun
2017 Radiation and Particles from the Photons Sun Photons (300000km/s ~ 8m 20s) radio waves, infra red, visible light, ultra violet, x-ray, x galactic waves, Solar Flux (30000km/s ~ 8m 20s) The 10.7 cm
More informationGet Discount Coupons for your Coaching institute and FREE Study Material at COMMUNICATION SYSTEMS
COMMUNICATION SYSTEMS 1. BASICS OF COMMUNICATION 2. AMPLITUDE MODULATION Get Discount Coupons for your Coaching institute and FREE Study Material at www.pickmycoaching.com 1 BASICS OF COMMUNICATION 1.
More informationPalle Preben-Hansen, OZ1RH
1 von 19 25.12.2010 20:02 Palle Preben-Hansen, OZ1RH If you are you an experienced DX'er you know that most stations work stations 5-800 km away in the VHF/UHF contests regardless of band conditions. How
More informationPropagation During Solar Cycle 24. Frank Donovan W3LPL
Propagation During Solar Cycle 24 Frank Donovan W3LPL Introduction This presentation focuses on: The four major fall and winter DX contests: CQ WW SSB and CW ARRL DX SSB and CW The years of highest solar
More informationPropagation Modelling White Paper
Propagation Modelling White Paper Propagation Modelling White Paper Abstract: One of the key determinants of a radio link s received signal strength, whether wanted or interfering, is how the radio waves
More informationVHF Operation and Field Day: FAQ s, Tips and Guides for Getting More Field Day QSOs
VHF Operation and Field Day: FAQ s, Tips and Guides for Getting More Field Day QSOs By: Steve Ford, WB8IMY, Editor, QST & ARRL s Public Relations Staff When most hams think of Field Day, they automatically
More information2 Propagation mechanisms responsible for propagation at frequencies above the basic MUF
1 REPORT ITU-R P.2011 PROPAGATION AT FREQUENCIES ABOVE THE BASIC MUF (1997) 1 Introduction Recommendation ITU-R P.373 defines the basic MUF as the highest frequency by which a radio wave can propagate
More informationFirst Results from the 2014 Coordinated Measurements Campaign with HAARP and CASSIOPE/ePOP
First Results from the 2014 Coordinated Measurements Campaign with HAARP and CASSIOPE/ePOP Carl L. Siefring, Paul A. Bernhardt, Stanley J. Briczinski, and Michael McCarrick Naval Research Laboratory Matthew
More informationRECOMMENDATION ITU-R P Guide to the application of the propagation methods of Radiocommunication Study Group 3
Rec. ITU-R P.1144-2 1 RECOMMENDATION ITU-R P.1144-2 Guide to the application of the propagation methods of Radiocommunication Study Group 3 (1995-1999-2001) The ITU Radiocommunication Assembly, considering
More informationRec. ITU-R P RECOMMENDATION ITU-R P *
Rec. ITU-R P.682-1 1 RECOMMENDATION ITU-R P.682-1 * PROPAGATION DATA REQUIRED FOR THE DESIGN OF EARTH-SPACE AERONAUTICAL MOBILE TELECOMMUNICATION SYSTEMS (Question ITU-R 207/3) Rec. 682-1 (1990-1992) The
More informationSection 1 Wireless Transmission
Part : Wireless Communication! section : Wireless Transmission! Section : Digital modulation! Section : Multiplexing/Medium Access Control (MAC) Section Wireless Transmission Intro. to Wireless Transmission
More informationWhat are the keys to better weak signal receive performance?
1 Determinants of receiver sensitivity What are the keys to better weak signal receive performance? One of the greatest advances we have seen in the last few years has been the application of Digital Signal
More informationLecture 12: Curvature and Refraction Radar Equation for Point Targets (Rinehart Ch3-4)
MET 4410 Remote Sensing: Radar and Satellite Meteorology MET 5412 Remote Sensing in Meteorology Lecture 12: Curvature and Refraction Radar Equation for Point Targets (Rinehart Ch3-4) Radar Wave Propagation
More informationIntroduction to: Radio Navigational Aids
Introduction to: Radio Navigational Aids 1 Lecture Topics Basic Principles Radio Directional Finding (RDF) Radio Beacons Distance Measuring Equipment (DME) Instrument Landing System (ILS) Microwave Landing
More informationThe Largest Ionospheric Disturbances Produced by the HAARP HF Facility
The Largest Ionospheric Disturbances Produced by the HAARP HF Facility Paul A. Bernhardt 1, Carl L. Seifring 1, Stanley J. Briczinski 2, Elizabeth A. kendall 3, Brenton J. Watkins 4, William Bristow 4,
More informationQuestion 15.1: Which of the following frequencies will be suitable for beyond-the-horizon communication using sky waves? (a) 10 khz (b) 10 MHz (c) 1 GHz (d) 1000 GHz (b) : 10 MHz For beyond-the-horizon
More informationMeasurements of doppler shifts during recent auroral backscatter events.
Measurements of doppler shifts during recent auroral backscatter events. Graham Kimbell, G3TCT, 13 June 2003 Many amateurs have noticed that signals reflected from an aurora are doppler-shifted, and that
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 information3C5 Telecommunications. what do radios look like? mobile phones. Linda Doyle CTVR The Telecommunications Research Centre
3C5 Telecommunications what do radios look like? Linda Doyle CTVR The Telecommunications Research Centre ledoyle@tcd.ie Oriel/Dunlop House 2009 mobile phones talk is cheap.. bluetooth 3G WLAN/802.11 GSM
More informationPerformance Of Troposcatter Communications with Different Diversity Technique on Fading Correlation Analysis
Performance Of Troposcatter Communications with Different Diversity Technique on Fading Correlation Analysis 1 P.Varunkumar JNTUA College of Engineering, Pulivendula, Andhra Pradesh 2 K.Aparna JNTUA College
More informationAntennas and Propagation
Antennas and Propagation Chapter 5 Introduction An antenna is an electrical conductor or system of conductors Transmission - radiates electromagnetic energy into space Reception - collects electromagnetic
More informationSupporting Network Planning Tools II
Session 5.8 Supporting Network Planning Tools II Roland Götz LS telcom AG / Spectrocan 1 Modern Radio Network Planning Tools Radio Network Planning Tool Data / Result Output Data Management Network Processor
More informationRadio Propagation Fundamentals
Radio Propagation Fundamentals Concept of Electromagnetic Wave Propagation Mechanisms Modes of Propagation Propagation Models Path Profiles Link Budget Fading Channels Electromagnetic (EM) Waves EM Wave
More informationPropagation for Space Applications
Propagation for Space Applications by Bertram Arbesser-Rastburg Chairman ITU-R SG3 Invited talk at LAPC 2014, Loughborough, UK bertram@arbesser.org Abstract:The presentation covers the key propagation
More informationRec. ITU-R P RECOMMENDATION ITU-R P PROPAGATION BY DIFFRACTION. (Question ITU-R 202/3)
Rec. ITU-R P.- 1 RECOMMENDATION ITU-R P.- PROPAGATION BY DIFFRACTION (Question ITU-R 0/) Rec. ITU-R P.- (1-1-1-1-1-1-1) The ITU Radiocommunication Assembly, considering a) that there is a need to provide
More informationTechnical Note: Path Align-R Wireless Supporting Information
Technical Note: Path Align-R Wireless Supporting Information Free-space Loss The Friis free-space propagation equation is commonly used to determine the attenuation of a signal due to spreading of the
More informationSuperDARN (Super Dual Auroral Radar Network)
SuperDARN (Super Dual Auroral Radar Network) What is it? How does it work? Judy Stephenson Sanae HF radar data manager, UKZN Ionospheric radars Incoherent Scatter radars AMISR Arecibo Observatory Sondrestrom
More informationProject = An Adventure : Wireless Networks. Lecture 4: More Physical Layer. What is an Antenna? Outline. Page 1
Project = An Adventure 18-759: Wireless Networks Checkpoint 2 Checkpoint 1 Lecture 4: More Physical Layer You are here Done! Peter Steenkiste Departments of Computer Science and Electrical and Computer
More informationUsing the Radio Spectrum to Understand Space Weather
Using the Radio Spectrum to Understand Space Weather Ray Greenwald Virginia Tech Topics to be Covered What is Space Weather? Origins and impacts Analogies with terrestrial weather Monitoring Space Weather
More informationLightning scatter: a faint and rare mode of propagation
Jean-L. Rault F6AGR Lightning scatter: a faint and rare mode of propagation Reflections on layers of the ionosphere, reflections on ionised meteorite trails, echoes on airplanes, EME, reflections on auroral
More informationA Terrestrial Multiple-Receiver Radio Link Experiment at 10.7 GHz - Comparisons of Results with Parabolic Equation Calculations
RADIOENGINEERING, VOL. 19, NO. 1, APRIL 2010 117 A Terrestrial Multiple-Receiver Radio Link Experiment at 10.7 GHz - Comparisons of Results with Parabolic Equation Calculations Pavel VALTR 1, Pavel PECHAC
More informationUnguided Media and Matched Filter After this lecture, you will be able to Example?
Unguided Media and Matched Filter After this lecture, you will be able to describe the physical and transmission characteristics of various unguided media Example? B.1 Unguided media Guided to unguided
More informationGuidelines for the Use of MGM in RSGB VHF Contests
Guidelines for the Use of MGM in RSGB VHF Contests Introduction These Guidelines describe the use of digital modes in RSGB VHF contests, referred to by the RSGB and IARU Region 1 as Machine Generated Modes
More information