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

Similar documents
Replacement of integrated circuit 24C02 or 8582

4 Antennas as an essential part of any radio station

Chapter 5.0 Antennas Section 5.1 Theory & Principles

AIR BAND ANTENNAS SUMMARY

CHAPTER 8 ANTENNAS 1

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

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

Basic Wire Antennas. Part II: Loops and Verticals

Q-MAC Launches New Antenna to revolutionise Vehicle HF communications.

Ten-Tec Model 3402 and 3403 Broadband Antennas Installation and Operation Manual PN 74393

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

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

BARRETT. 911 Automatic antenna tuner Installation instructions. General. Specifications COMMUNICATIONS

SB-400 HF Antennas SB-400

Technician Licensing Class. Antennas

CHAPTER 9 HIGH FREQUENCY RADIO OPERATION CHAPTER

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

Technician License. Course

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

Technician Licensing Class T9

SD230T. Frequency Range, MHz Average, 0.6 PEP,1 Average, 3 PEP. <2.0:1 for 3 to 20MHz, <2.5:1 for 2 to 30MHz

3000 Series Granger Broadband HF Multi-Mode SPIRA-CONE Antennas

The Fabulous Dipole. Ham Radio s Most Versatile Antenna

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

Portable Vertical Antenna Counterpoise Kit (CHA COUNTERPOISE KIT) Operator s Manual

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

Beams and Directional Antennas

Half-Wave Dipole. Radiation Resistance. Antenna Efficiency

This is Issue 3 of the HF Radio Communications International Product Catalogue, 16th July 2007.

Portable Antenna Spike Mount (CHA SPIKE MOUNT) Operator s Manual

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

ANTENNA BASICS FOR BEGINNERS

The EMCOMM Easytenna

Emergency Antennas. Presented by Ham Hilliard W4GMM

Testing and Results of a New, Efficient Low-Profile AM Medium Frequency Antenna System

Miniature Magnetic Loops By David Posthuma, WD8PUO

Technician License. Course

NGT TRANSCEIVER. This is Issue 7 of the HF Codan Radio Communications Commercial Product Catalogue, January 2014.

Newcomers And Elmers Net: Wire Antennas Robert AK3Q

Antenna Basics. A general guide for antenna selection and installation techniques

INSTRUCTION MANUAL HF AUTOMATIC TUNING ANTENNA AH-740. * The stand in the photo is not supplied with the tuning antenna.

Other Arrays CHAPTER 12

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

Chapter 3 Antennas. Section I. Antenna Selection FM 24-19

MFJ Manual Loop Tuner Considerations

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

M2 Antenna Systems, Inc. Model No: 2M HO LOOP

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).

Antennas Demystified Antennas in Emergency Communications. Scott Honaker N7SS

Microair Avionics Pty Ltd ABN VHF Aerial Installation FAQ

Array Solutions OCF Series Dipoles

CHAPTER - 6 PIN DIODE CONTROL CIRCUITS FOR WIRELESS COMMUNICATIONS SYSTEMS

A Review of WICEN HF Communications Capability

MFJ-2389 Compact 8 Band Vertical

Table of Contents. MFJ-1778 G5RV Multiband Antenna

Fundamentals of Antennas. Prof. Ely Levine

The DBJ-1: A VHF-UHF Dual-Band J-Pole

Small Magnetic Loops: A Beginner s Guide WOW! This is a very different antenna!

Introduction. Understanding Power Ratings. Peak Reading SWR/Wattmeter

INDEX. HF PORTABLE ANTENNAS HF Collapsible Backpack Whip (with Goose neck) 30 HF Tactical Broadband Antenna 31 HF Manpack Tape Whip 32

Jacques Audet VE2AZX. Nov VE2AZX 1

COAXIAL TRANSMISSION LINE COMMON-MODE CURRENT

Coming next: Wireless antennas for beginners

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

Cisco Aironet Omnidirectional Mast Mount Antenna (AIR-ANT2506)

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

Portable Magnetic Loop Antenna. KG5EAO Rick Bono

FCC Technician License Course

Ground-Mounted Verticals. Dispelling the Myths and Misconceptions

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

MFJ ENTERPRISES, INC.

G7FEK LIMITED SPACE ANTENNA

ANTENNAS Wires, Verticals and Arrays

Computer Networks Lecture -4- Transmission Media. Dr. Methaq Talib

Antenna Glossary. BEAMWIDTH The angle of signal coverage provided by an antenna. Beamwidth usually decreases as antenna gain increases.

TENNADYNE TD-160HP800

Loop Antennas for HF Reception

TW4040. The Adventurer Monobander INSTRUCTION MANUAL. TransWorld Antennas

General Class License Theory III. Dick Grote K6PBF

General Product Brochure

TRANSPORTATION COMMUNICATION SOLUTIONS

A Guide to building your own Portable Station Incorporating a ¼ Wave Vertical Antenna and a Ground Tuning Unit or GTU

Magnetic Loop Antenna - Topbands

TRANSPORTATION COMMUNICATION SOLUTIONS

Portable or Emergency VHF Antennas Paul R. Jorgenson KE7HR

Lesson 11: Antennas. Copyright Winters Version 1.0. Preparation for Amateur Radio Technician Class Exam

CON NEX HP. OWNER'S MANUAL Full Channel AM/FM Amateur Mobile Transceiver TABLE OF CONTENTS TUNING THE ANTENNA FOR OPTIMUM S.W.R..

Bob Brehm, AK6R Chief Engineer Palomar-Engineers.com

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

User Guide. For. Alpha Antenna. Model: Multiband (Black Match)

User Guide for the Alpha Antenna 6 40 or meter OCF Dipole

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

87.5 TO MHz BAND II 2 WAY 4.8dBi STACKED DIPOLE ANTENNA

A Transmatch for Balanced or Unbalanced Lines

WCARES NEEDS YOU! CONSIDER MAKING A TECHNICAL PRESENTATION AT AN UPCOMING CHEW & CHAT MEETING LEARN SOMETHING NEW AND PRESENT

Chapter 9 Antennas and Feedlines

Range Considerations for RF Networks

CP6 6 Band Trap Vertical 80-6m

TZ-RD-1740 Rotary Dipole Instruction Manual

Bob Brehm, AK6R Chief Engineer Palomar-Engineers.com

Transcription:

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 document is divided into four sections: Antenna Selection Proforma Fundamental Antenna Selection Criteria Practical Antenna Selection Criteria general information section outlining the aspects of each antenna For higher power applications (>125 W PEP) please contact your Codan representative for specific antenna models and suitability. Using the Antenna Selection Proforma In order to determine which antenna best suits your needs, it is important that you consider a series of criteria. We have included an Antenna Selection Proforma in this document so you can record your considerations, and therefore reach an informed decision about which antenna best suits your particular requirements. We have divided these criteria into two categories: Fundamental Criteria (see page 3) Practical Criteria (see page 5) Some additional information is given at the beginning of each of the Fundamental and Practical Criteria sections. This information explains how to use the Antenna Selection Proforma effectively. CODAN ANTENNA MATRIX Head office www.codan.com.au 12-50133 Issue 3, October 2001 Page 1 of 16 Codan Limited ABN 77 007 590 605 81 Graves Street Newton SA 5074 AUSTRALIA Codan Limited ABN 77 007 590 605 532 Seventeen Mile Rocks Road Sinnamon Park Qld 4073 AUSTRALIA Telephone +61 8 8305 0311 Telephone +61 7 3291 6333 Facsimile +61 8 8305 0411 Facsimile +61 7 3291 6350 asiatech.support@codan.com.au Codan (UK) Ltd Gostrey House Union Road Farnham Surrey GU9 7PT UNITED KINGDOM Telephone +44 1252 717 272 Facsimile +44 1252 717 337 uktech.support@codan.com.au Codan Pty Ltd 10660 Wakeman Ct Manassas VA 20110 USA Telephone +1 703 361 2721 Facsimile +1 703 361 3812 ustech.support@codan.com.au

Fundamental criteria Antenna Selection Proforma Maximum communication distance Minimum communication distance km km Maximum frequency Minimum frequency MHz MHz Distance from transceiver to antenna metres Antenna position: rooftop ground mobile Possible antenna choices Practical criteria Space requirements noted Grounding requirements noted Civil works requirements noted Budget constraints noted Benefits and limitations noted Final antenna choice Notes: Page 2 of 16 12-50133 Issue 3, October 2001

Fundamental Criteria The fundamental criteria for selecting an antenna cover the basic requirements of your system, e.g. communication distance, frequency range, etc. Communication distance Fill out the Antenna Selection Proforma with your expected maximum and minimum communication distances. This information is important as antennas have different capabilities over distance. Frequency range Fill out the Antenna Selection Proforma with your expected maximum and minimum frequencies. This information is important as antenna models have different capabilities over the range of HF. Distance between transceiver and antenna Fill out the Antenna Selection Proforma with the expected distance between the transceiver and the antenna. This distance will dictate the type of coaxial cable to be used in the installation, and may even eliminate some antennas from the selection process. Type of installation Fill out the Antenna Selection Proforma with the expected type of installation, i.e. rooftop, ground or mobile. Some antennas are very specific to the installation, e.g. a C411 antenna cannot be used in a mobile installation. Antenna choices based on the fundamental criteria Use the information provided in Table 1 to select those antennas that are most suitable for your requirements. Write your choices in the spaces provided on the Antenna Selection Proforma. 12-50133 Issue 3, October 2001 Page 3 of 16

Page 4 of 16 12-50133 Issue 3, October 2001 Table 1: Antenna Type Fundamental antenna selection criteria Product Code Typical operating distance (km) Frequency range (MHz) Allowable distance between antenna and transceiver Horizontal Wire Dipole 400 0 1500 single frequency 30 m a Broadband 411B 0 1000 2.0 7.5 100 m b Broadband Dipole c a. Use RG58 coaxial cable b. Use RG8 coaxial cable c. Use 9103 Automatic Antenna Tuner d. High power models available Tuner required? Antenna Location Rooftop Ground Mobile no á á à no á á à 411C 0 1500 2.5 9.0 as above no á á à 411D 0 1500 3.0 12.0 as above no á á à 411E 0 1500 4.0 15.0 as above no á á à 411F 0 1500 5.0 18.0 as above no á á à 408 250 1500 2.0 15.0 as above no á á à 408L 250 1500 3.0 25.0 as above no á á à Inverted V Active Tuned Dipole 451 250 1500 2.0 30.0 30 m yes d á á à Broadband 411B 250 1500 2.0 7.5 30 m a 100 m b no á á à 411C 250 1500 2.5 9.0 as above no á á à 411D 250 1500 3.0 12.0 as above no á á à 411E 250 1500 4.0 15.0 as above no á á à 411F 250 1500 5.0 18.0 as above no á á à Delta 4 D230 0 1000 2.0 30.0 as above no à á à D330 0 1000 3.0 30.0 as above no à á à Vertical Tuned Whip 406 500 200 2.0 30.0 30 m yes c á á à Auto Tuning Whip 9350 200 1500 2.0 30.0 6 m included à à á Tapped Whip 300 200 1500 2.0 30.0 6m no à à á Sloping Semi Delta d SD214 0 1500 2.0 14.0 30 m a 100 m b no á á à Long Wire 403 250 1500 2.0 30.0 30 m yes c á á à Antenna Matrix

Practical Criteria The practical criteria for selecting an antenna covers the broader constraints that your particular circumstances may place on your choice of antenna. Refer to the information provided in Table 2 to consider your answers to the following questions: Do you have enough physical space at the intended antenna site? Does the antenna require grounding? Are there any civil works required? Have you considered how much can be spent on the antenna? Have the benefits and limitations of the antenna been carefully considered? Please check the boxes provided on the Antenna Selection Proforma to indicate that you have considered the questions above. 12-50133 Issue 3, October 2001 Page 5 of 16

Page 6 of 16 12-50133 Issue 3, October 2001 Table 2: Antenna Type Practical antenna selection criteria Product code No. of masts Installation site requirements Distance between masts (m) Height (m) Grounding requirements Benefits Horizontal Wire Dipole 400 2 142/f (MHz) 71.0/f (MHz) None required Highly efficient, requires no earth system, cost effective Broadband 411B 2 58 13 None required Good performance, lightweight, easy to install, cost effective Broadband Dipole Inverted V Active Tuned Dipole Limitations Single frequency, not suitable for scanning networks Narrow frequency range, requires large installation site Typical Applications Base to base fixed frequency 411C 2 47 10 None required As above As above As above 411D 2 38 8 None required As above As above As above 411E 2 31 6.5 None required As above As above As above 411F 2 26 5.5 None required As above As above As above 408 2 64 15 None required Excellent performance, high quality components Expensive, requires substantial support structures and large installation site 408L 2 46 15 None required As above As above As above 451 1 centre mast 2 stub masts/anchor points Broadband 411B 1 centre mast 2 stub masts 411C 411D 411E 411F 1 centre mast 2 stub masts 1 centre mast 2 stub masts 1 centre mast 2 stub masts 1 centre mast 2 stub masts Delta D230 1 centre mast 2 ground anchor points Centre to stub mast: 9 Centre to stub mast: 27 Centre to stub mast: 22 Centre to stub mast: 18 Centre to stub mast: 14.5 Centre to stub mast: 12 Centre to ground point: 29 Centre: 6 Stub: 1 Centre: 16 Stub: 6 Centre: 13 Stub: 4.2 Centre: 11 Stub: 4.8 Centre: 8 Stub: 3 Centre: 6.5 Stub: 2.4 None required None required Easy to install, requires no earth system, requires one main mast Good long distance, requires one main mast, smaller installation site than horizontal configuration, cost effective Added cost of antenna tuner, inferior performance compared to full size broadband antennas Narrow frequency range, large installation site, performance may be inferior to 408 type antenna Base to base/mobile communications, suitable for data/voice/ scanning networks As above None required As above As above As above None required As above As above As above None required As above As above As above None required As above As above As above Centre: 22 None required High performance, two antennas may be mounted on same mast for transmitting Expensive, requires large installation site Rooftop installations for multifrequency data/ voice/scanning networks Base to base/mobile multifrequency communications, suitable for data/voice/ scanning networks Communication stations requiring quality voice/ data/scanning network Antenna Matrix

12-50133 Issue 3, October 2001 Page 7 of 16 Table 2: Antenna Type D330 1 centre mast 2 ground anchor points Centre to ground point: 23 Vertical Tuned Whip 406 Clear area of at least 8 m diameter Ground code 158 earth mat Roof code 159 ground plane Auto Mobile Whip Tapped Mobile Whip Practical antenna selection criteria (cont.) Product code No. of masts Installation site requirements Distance between masts (m) 9350 Heavy duty mounting bracket on vehicle Good electrical connection to vehicle chassis and body 300 Suitable mounting bracket on vehicle Good electrical connection to vehicle chassis and body Sloping Semi Delta SD214 2 20 Centre: 15 Stub: 2 Height (m) Long Wire 403 High anchor point at least 15 m: low anchor point approximately 2 m and within 2 m of earth system connection Grounding requirements Centre: 16.5 None required As above As above As above Ground well grounded stub mast Roof 5 copper radials under antenna Ground 3 x 3 m copper earth stakes driven into moist soil Roof 5 copper radials under antenna Suits small sites, easy to install, good long distance performance No manual changing of settings, durable construction, receiver scanning possible Simple, reliable, cost effective Suits small sites, excellent performance, cost effective Adaptable installation configurations, minimal support structures, broadband operation Poor short distance performance, requires antenna tuner, susceptible to local electrical noise Expensive, poor short distance performance unless NVIS a kit fitted Average performance, maximum of 10 frequencies, manual retuning, no receiver scanning Difficult to install, requires quality earth system, limited frequency range Inferior performance to full sized broadband antennas, requires earth system Networks requiring long distance multifrequency communications, but have limited antenna installation space Mobile vehicles requiring flexible, high performance HF communications Mobile vehicles requiring basic, medium performance HF communications Base stations requiring quality broadband antenna for short to medium distances Base stations requiring multifrequency operation, suitable for semi-permanent stations a. Short vertical whip antennas, like the 9350 Automatic Tuning Whip Antenna provide poor performance over short distances. Performance over 20 500 km range may be improved by the addition of an NVIS (Near Vertical Incidence Skywave) antenna kit. Note: The frequency range of the NVIS kit is 1.6 12 MHz Benefits Limitations Typical Applications Antenna Matrix

Antenna data sheets The application and technical details for each type of Codan antenna are available on specific data sheets. These describe the type of installation required and the characteristics for the antenna, including radiation patterns where applicable. These data sheets are available from your Codan representative. Naming convention of Codan antennas For ease of selection, antennas manufactured by Codan can be identified by their product code numbers e.g. Code 401. Special application and high power antennas are coded differently, e.g. Semi Delta and Delta types SD214 and D230. Masts and accessories Codan is able to supply a range of installation hardware to suit your requirements. These include metal masts, halyards, low-loss coaxial cables and earthing hardware. For advice on these matters please contact your Codan representative. Page 8 of 16 12-50133 Issue 3, October 2001

Antennas for fixed installations Wire Dipole Antenna (Code 400-1) The wire dipole antenna is a highly efficient, half wavelength wire dipole. The dipole antenna is large in size, but easy to install. The antenna is raised horizontally above the ground, normally between two vertical masts or towers. The wire dipole antenna is fed by a direct 50 Ω coaxial cable connection from the transceiver, which must be properly earthed. Figure 1: Wire dipole antenna The Code 400-1 has some inherent rejection of broadband noise compared to broadband antenna. At lower operating frequencies where the wavelength is longer, the dipole can require considerable space e.g. at 2 MHz, the physical half wavelength is 75 metres. The dipole does not require an artificial earth plane to radiate efficiently. For the best results make sure that the antenna is broadside to the destination of the frequency, as poor radiation is emitted off the ends of the antenna. The Code 400-1 is manufactured to the user s specified frequency and is suitable only for single frequency operation. Long Wire Antenna (Code 403) The long wire antenna is an untuned length of wire, cut to 23 metres. It is designed to be used with the Codan Automatic Antenna Tuner 9103. It exhibits a good combination of efficiency and broadband capability. This antenna is useful where space is limited. The tuner enables the wire to be resonated to frequencies within the HF band from 2 to 30 MHz. The long wire antenna is normally erected as shown in Figure 2, where the high end is supported on a suitable mast or tower, and the low end is connected to the insulated RF output of the tuner. 12-50133 Issue 3, October 2001 Page 9 of 16

Figure 2: Long wire antenna The tuner is fed by a 50 Ω coaxial cable from the transceiver. For reliable operation, the tuner requires a substantial earth system. Codan can supply the necessary earthing components if required. Base Whip Antenna (Code 406 series) The base whip antenna is 10 metres overall in height and will require Codan s Automatic Antenna Tuner 9103 to enable resonance within the HF band. The antenna is constructed of lightweight metal tubing (active element) and is mounted vertically on a suitable ground plane or metal roof. Figure 3: Base whip antenna Page 10 of 16 12-50133 Issue 3, October 2001

The antenna is supplied with four guy wires, which may be anchored to suitable points at ground level to support the antenna in the vertical position. This antenna may be used where space is restricted and omnidirectional coverage is required. Do not choose the antenna on this point alone as it does not perform well for short distance communication. The antenna may be susceptible to local electrical noise due to its vertical orientation. Broadband Dipole Antenna (Code 407/408) The broadband dipole antenna is a three element, centre-fed antenna. It is one of the original types adopted by Codan to fill the requirement for a wide or broadband antenna. In its original form, it was known as a travelling wave antenna. The design has some of the advantages of the single frequency dipole, but is able to operate over a wide range of frequencies, therefore eliminating the need for multiple antennas or antenna tuners. The broadband dipole antenna is a durable antenna and while it requires a substantial amount of space for installation, it will offer superior on-air performance. It exhibits omnidirectional radiation capabilities, except for close range communications where the antenna should be orientated broadside to the preferred direction of transmission. As with all broadband, untuned antennas, it will be susceptible to local and atmospheric noise reception. The current models cover a frequency range of 2.2 to 15 MHz (407, 408) or 3.0 to 20 MHz (407L, 408L). The antenna is mounted horizontally above the ground. The Code 407 is a high power, 1 kilowatt, version of the Code 408. Figure 4: Broadband dipole antenna 12-50133 Issue 3, October 2001 Page 11 of 16

Broadband Terminated Folded Dipole Antenna (Code 411) The broadband terminated folded dipole antenna is a two element, centre-fed antenna. The Code 411 provides good performance while being suitable for the budget conscious. It is available in a range of lengths depending on the operating bandwidth that the customer requires. There are 5 models (B, C, D, E, and F), which range in overall length from 27 to 56 metres and have extended frequency coverage between 2 to 30 MHz. As with all broadband, untuned antennas, it is susceptible to local and atmospheric noise reception. Figure 5: Broadband terminated folded dipole antenna horizontal configuration The antennas are easy to install, but do require a substantial amount of space, especially for lower frequencies. The Code 411 antennas are relatively lightweight and can be raised on two masts as shown in Figure 5, or they may be supported at the centre by a single mast in what is known as an inverted V configuration (Figure 6). Figure 6: Broadband terminated folded dipole antenna inverted V configuration Stub mast Mast 22 recommended angle The inverted V type of installation will require two shorter stub masts or suitable tie off points to support the ground end of the antenna. Page 12 of 16 12-50133 Issue 3, October 2001

Active Tuned Dipole Antenna (Code 451) The active tuned dipole antenna is made up of two radiating elements and a 9103 Automatic Antenna Tuner installed on a 6 m mast. One element is connected to the earth terminal of the tuner and the other to the antenna terminal of the tuner. The antenna configuration is adjustable, but is commonly installed on a single mast in an inverted V configuration. It is a dipole antenna that can be tuned over the full 2 30 MHz HF band. The antenna is suited to sites where poor ground conditions exist and/or where an earth mat is impractical. The span of the antenna is 20 m, which is useful where space restrictions apply. The Code 451 can be installed in a variety of configurations and provides a suitable alternative for customers who want the convenience of a broadband antenna, but do not have the space or performance requirements for a full-sized antenna. Figure 7: Active tuned dipole antenna Delta Antenna (Codes D230, D330) The delta antenna is a professional, high performance broadband antenna. It exhibits omnidirectional characteristics and performs well over very short to medium distances. The delta wire elements are supported by a single guyed metal mast (between 16 22 m in height) and will handle input powers between 200 1000 watt PEP, depending on the model. Two of these antennas may be mounted on the same mast and used for separate transmitter feeds if required. Up to 30 db of isolation between antennas can be achieved. Generally these antennas require a large cleared area at ground level for installation and are more suitable for permanent higher powered installations. 12-50133 Issue 3, October 2001 Page 13 of 16

Figure 8: Delta antenna Semi Delta Antenna (Code SD214) The semi delta antenna is an excellent broadband antenna providing a good compromise between performance and price. It exhibits omnidirectional characteristics and performs well over short to medium distances. Generally these antennas require a large cleared area at ground level for installation and are more suitable for permanent low and high powered installations. During installation, consideration should be given to the antenna earthing, especially when mounted on rooftop locations, or at ground level where the soil conditions are poor. Figure 9: Semi delta antenna Low frequency kit (if fitted) Page 14 of 16 12-50133 Issue 3, October 2001

Antennas for mobile installations Automatic Tuning Whip Antenna (Code 9350) The automatic tuning whip antenna is a state-of-the-art antenna designed exclusively for mobile HF applications. The antenna eliminates the need for manual retuning of the antenna when changing frequencies. It is suitable for scanning networks. During installation, consideration must be given to antenna positioning, mounting and the provision of adequate earthing. The antenna is of robust construction and, because of its composite protective casing and shock-mounted base, it is able to withstand the rigours of off-road travel. It features fully automated tuning over the HF range. Figure 10: Automatic tuning whip antenna 12-50133 Issue 3, October 2001 Page 15 of 16

Tapped Whip Antenna (Code 300) The tapped whip antenna is a helically wound, pretapped, vertical-mounting antenna. Each whip can be tapped to a maximum of 10 discrete frequencies. The antenna may be ordered with the customer s choice of frequencies. Manual retuning of the antenna is necessary whenever changing operating frequencies, therefore, the antenna is not suitable for scanning networks. A Code 301 spring mounting base and coaxial cable is required to complete the installation. Special consideration must be given to antenna positioning, mounting method and the provision of adequate earthing. Figure 11: Tapped whip antenna Page 16 of 16 12-50133 Issue 3, October 2001