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Ramsey Electronics DA-1
Looking for an easy to build, solid performing antenna? The
dipole is hard to beat! These inexpensive, high quality
antennas are the time tested solution to price, relative
invisibility, and most of all, performance.
• User tested, proven antenna technology to bring you the best
value.
• Clear, concise instructions are just what you won’t find with other
antennas. Our manual teaches you everything that you need to
know, and even points you in the right direction if you want to learn
more!
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• Can be set up as a typical dipole antenna, or the popular “Inverted
V” configuration, for less space and excellent performance.
• Build a home brew antenna... right down to the last soldering
connection.
• These dipoles are virtually invisible, but do not compromise
performance, or signal capabilities.
• Perfect as a second antenna for those whose antennas won’t
handle a specific band.
• High quality components assure you a working antenna every
time... and tuning it is so easy!
• The right antenna at the right price.
RAMSEY DA SERIES DIPOLE ANTENNA Page 1
PARTIAL LIST OF AVAILABLE KITS
RAMSEY TRANSMITTER KITS
• FM-10 FM Stereo Transmitter
• FM-1,2,4 FM Wireless Microphones
• PB-1 Telephone Transmitter
• AM-1 AM Transmitter
RAMSEY RECEIVER KITS
• FR-1 FM Broadcast Receiver
• AR-1 Aircraft Band Receiver
• SR-1 Shortwave Receiver
• AA-7 Active Antenna
• SC-1 Shortwave Converter
RAMSEY HOBBY KITS
• SG-7 Personal Speed Radar
• SS-7 Speech Scrambler
• MM-5 Digital Music Maker Machine
• SP-1 Speakerphone
• MD-3 Microwave Motion Detector
• PH-10 Peak hold Meter
• LC-1 Inductance-Capacitance Meter
RAMSEY AMATEUR RADIO KITS
• FX Series VHF and UHF Transceivers
• HR Series HF All Mode Receivers
• QRP Series HF CW Transmitters
• CW-7 CW Keyer
• PA Series VHF and UHF Power Amplifiers
• Packet Computer Interfaces
• QRP Power Amplifiers
RAMSEY MINI-KITS
Many other kits are available for hobby, school, scouts and just plain FUN. New
kits are always under development. Write or call for our free Ramsey catalog.
DP-1 DIPOLE ANTENNA INSTRUCTION MANUAL
Ramsey Electronics publication No. MDA-1 Revision 1.0
COPYRIGHT
14564. All rights reserved. No portion of this publication may be copied or duplicated without the
written permission of Ramsey Electronics, Inc. Printed in the United States of America.
1994 by Ramsey Electronics, Inc. 793 Canning Parkway, Victor, New York
First printing: August, 1994
Page 2
RAMSEY DA SERIES DIPOLE ANTENNA
Ramsey Publication No. DA
Manual Price Only: $5.00
ASSEMBLY
AND INSTRUCTION MANUAL FOR
DIPOLE
ANTENNA KIT
TABLE OF CONTENTS
Introduction ......................................................... 4
Antenna Description ............................................ 4
How Does a Dipole Antenna Work? ................... 6
Schematic Diagram ............................................. 7
Parts List ............................................................. 8
What Kind Of An Antenna Is Best For You? ....... 9
Construction Notes ............................................. 10
Antenna Construction ......................................... 13
Tuning Your Antenna .......................................... 15
Other Reading ..................................................... 15
RAMSEY DA SERIES DIPOLE ANTENNA Page 3
RAMSEY ELECTRONICS, INC.
793 Canning Parkway
Victor, New York 14564
Phone (716) 924-4560
Fax (716) 924-4555
INTRODUCTION
Welcome to your new dipole antenna. Dipole antennas are an extremely
popular form of antenna today, because they satisfy the demands of almost
any application! There are not many antenna designs that are so low cost,
simple and “invisible”. You may not know that they are also exceptionally
good radiators, beating many other antennas hands down. Their exceptional
qualities on low frequency bands such as 160, 80 and 40 meters is also a
great advantage over antennas many times their price.
As you may know, living in a neighborhood with other people may
immediately lead to problems with neighbors who are worried about the
effect that your antenna will have on them. Many people are worried about
your ham gear interfering with their television sets or radios. In addition,
many people who simply don’t know enough about your hobby may think
that it could attract lightning to their houses, or even fall off of your roof
(heaven forbid!) This is where the “invisible” properties of a dipole are so
important. In a short day’s work, you can install your antenna that to even
the nosiest neighbor might be strained to see.
But the great thing is that your antenna is also a great radiator. Is it any
wonder why hams who spend over a thousand dollars on beam antennas for
20, 15 and 10 meters also own dipoles to work the 160, 80 and 40 meter
bands? In fact, dipoles are one of the oldest, and most tested antennas in
existence. This is why we are proud to offer you a reliable, time tested
antenna design at low cost.
ANTENNA DESCRIPTION
Your Ramsey antenna has been designed for practicality, performance and
price. Every effort has been made to offer you not only high quality parts,
but also an affordable price that will make beginners starting in the hobby, or
avid hams looking for a second antenna feel good. Because we offer a
range of antennas, each designed for a different band, you will notice that
this book encompasses each of them. In the tables provided, use the data
that best resembles your particular purpose and needs.
Page 4
RAMSEY DA SERIES DIPOLE ANTENNA
HOW DOES A DIPOLE ANTENNA WORK?
A dipole antenna is a long wire that is suspended between two points. The
wire is cut to a specific length, and is fed in the middle with a radio frequency
(RF) signal. One half of the antenna is hooked to the ground wire of the
transmission line, and the other is hooked to the center conductor.
As an RF signal is applied to a piece of wire, both an electric and a
magnetic field is set up around the wire. These waves propagate through
the air (or ether!) without limit. As these magnetic and electric fields reach
another station’s antenna (or about any other metal object in it’s path) the
exact reverse effect takes place on our antenna that our RF signal did. The
rapidly changing fields produce an RF current that your receiver can detect.
Although it is impossible to actually see the waves coming off of a dipole,
we can try to visualize it to understand it better. Take a piece of paper and
push a pen or pencil through the center. Hold it up in front of you. Let’s
pretend that the pencil represents our antenna, and the paper represents
where our signal is concentrated. As you can see, most of the radiation is
given off at a 90 degree angle to the antenna, with very little radiation
occurring parallel to the pencil. It is this property that makes the dipole
directional. Another advantage is that the radiation is at all angles around
the wire, and the signal has a maximum chance to skip through the
atmosphere, making the dipole ideal for DX.
An inverted dipole does have a number of advantages over typical dipoles.
For one thing, they take up less space, with some of their wire being used up
to climb a vertical distance, and a five percent reduction in antenna length
over a normal dipole. They also match their impedance more easily to a 50
ohm coaxial cable than a typical dipole, which has an impedance of 65
ohms. The inverted dipole also has a higher angle of radiation — making it
better for sky wave DX.
If you have any questions, we suggest that you look for the ARRL Handbook,
which has all sorts of great information for hanging antennas.
RAMSEY DA SERIES DIPOLE ANTENNA Page 5
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