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Ramsey Electronics DA-40
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
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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
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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 P
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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 man
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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 ai
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PARTS LIST 3 End Insulators Length of Coaxial Feedline Cable Length of Rope 1 PL-259 Connector 1 UG-175/U Reducer Length of Antenna Wire 2 Wire Cable Ties REQUIRED, NOT SUPPLIED Some Good Friends (Suckers) Soldering Iron Gun with Rosin Core Solder Waterproof Sealant (Silicone) and Electrical Tape Radio Transmitter Sharp Knife Wire Cutters WHAT KIND OF ANTENNA IS BEST FOR YOU? Unlike ma
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RAMSEY DA SERIES DIPOLE ANTENNA Page 7
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length, we have included a bit more wire than you should need to build either antenna. This allows you to decide which antenna will serve you better. CONSTRUCTION NOTES Just a few notes before you begin constructing your antenna. • Be careful when constructing your antenna! Throwing rocks through windows, falling from trees, shooting a buddy during the famous bow and arrow trick and becoming electrocuted are just a few of the hazards that can ruin your day. • If the weather looks
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Total length or an Inverted V = 445/ frequency (in MHz) (in feet) Your Frequency_________ Calculated Length___________ Antenna Wire Length (per side) ANTENNA FREQUENCY NORMAL INVERTED BAND (KHz) DIPOLE V ALL BAND > 1850 129’3” 122’9” 160m 1850 129’3” 122’9” 80m 3750 63’9” 60’6” 40m 7050 33’11” 31’6” 20m 14250 16’9” 15’8” 10m 28500 8’5” 7’11” NOTE: Measurements indicated for each side of dipole. RAMSEY DA SERIES DIPOLE ANTENNA Page 9
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For example, to make a dipole antenna on 14.050 MHz, divide 468 by 14.05. The total dipole length be 33.31 feet or approximately 33 ‘4”. Don’t forget that you need to insert a feedline in the center, so it must be cut into two pieces that are one half the length (16 feet, eight inches). Wire Length (approximate length packed with indicated antenna kit) 160m or ALL BAND .................. 262’ 80m ..................
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ASSEMBLING THE ANTENNA Start by finding three locations to attach your antenna. The center location must be close enough to your ham shack so that the coaxial cable will reach, but should also be as high as possible. Attaching it to a location on the roof, or to the chimney is a great place, as long as you are sure that the wires will not come into contact with trees, power lines (cringe!) or the house. Remember what that great ham, W2BOZO said, “If you touch a powerline with
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Taking the end of one of the wires, pass it through the hole in the insulator until six inches are through. Next, bend the wire back on itself and immediately begin to wrap it very snugly and neatly around itself. Ideally, you should have about six or seven turns. Using your soldering iron, heat up the wire turns and solder each of them until the wire is secured very tightly. This way, the loops take up most of the stress, but the solder keeps it from getting loose. Connect the o
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1 in. 1 in. WIRE TIES SOLDER TO ANTENNA WIRE wire. You should make sure that the center conductor fits through the hole in the center pin, and there are no stray strands being folded backwards. This will have the unfortunate tendency of shorting out your antenna. The connector should cover the braided wire and trap it against the reducer. Snug it down so that it is firmly on the wire. The braided shield should be caught between the reducer and connector and be held in very tightly.
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stranded lead about one inch long. Next, strip the center conductor 1/4 inch closer to the end. Tin both leads. Wrap the coax wire around the center insulator making sure that it is snug in one of the two grooves. The end of the coax should loop around and fold back on itself, overlapping about one inch. Fasten the coax to itself using the nylon wire ties supplied. You should still have a short length of wire coming from each antenna wire connection. Connect one of these t
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TUNING YOUR ANTENNA Hook up your radio to an SWR meter and the antenna. Set it for a portion of the band that you think you will be using most often. Since all of our antenna length calculations are for the center of the band, the antenna should be slightly longer if you wish to work below this frequency, and slightly shorter if you work above it. Reduce your power down to it’s lowest setting and transmit on a clear frequency. Your SWR meter should now be measuring the SWR of
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DA DIPOLE ANTENNA Quick Reference Page Guide Introduction ......................................................... 4 Antenna Description ........................................... 4 How Does a Dipole Antenna Work? ................... 6 Schematic Diagram ............................................ 7 Parts List .............................................................
