20 40 Meter Dipole Antenna

The four bands planned are 80 meters, 40 meters, 20 meters, and 10 meters. It is symmetrically loaded with two 6 meter long wires (12 AWG, THHN) that are attached to the top and bottom, and parallel to the mast at a separation of 40 cm. Double Bazooka NVIS Antenna Calculator. MFJ-17754 40/20 Meter Dipole Instruction Manual 1 The MFJ-17754 is a two band, 40- and 20-Meter center-fed dipole antenna capable of handling 1500 watts. 16’ ¼ lambda 60 METERS = 62. The 4-Band antennas are OCF (off-center-fed), with a 23 foot leg and a 45 foot leg, totaling 68 feet. Enter the desired operating frequency in megahertz to get a good starting length for a dipole in both feet and meters. My very first QSOs from here in Denver were to eastern Nebraska; Oklahoma; and Washington, on 20, 40 and 80 meters, so I am very pleased with that. Step-by-Step: With those measurement devices in mind, let's consider the big picture practical steps of trimming a dipole antenna: Determine the band and frequency range for which you desire the antenna trimmed. 5 on 80, most of 75, 40, 20, 17, 10 and 6. Being the crafty maker type, I wanted to build my own antenna. impedance of 50 ohms with a half wave length antenna, and the capacitor should have the ability to handle the R. A Portable Twin-Lead 20-Meter Dipole With its relatively low loss and no need for a tuner, this resonant portable dipole for 14. This multiband vertical designs provide 9 band coverage encompassing the 6, 10, 12, 15, 17, 20, 30, 40 and 80 meter bands. I have a 20 meter only inverted V in my backyard. OVERVIEW: The antenna is fed with a SO-239 connector attached to an. And the MFJ-1775 has a 2-3 S-unit LOWER noise floor on 40-meters compared to the vertical. This article is a well-organized tutorial that explains the theory, design, and construction of a 20/40 meter trap dipole antenna, including a list of materials and how to build the traps. Added an additional three or so feet to each length as the wound coils shortened each leg-wire of the antenna (with coil in place 40-meter length still needs to be 25-feet and 80-meter with coil in place still needs to be 38-feet in length). I've used fan dipoles for many years both at home (75/160) and rattlesnake island (40/75/160). The HFp Dipole For the HFp Ventenna Dipole, the element length is set according to the element chart in the Dipole instructions. At 66 feet – 1/2 wavelength high, the antenna has a good pattern on 40 Meters, and some gain over a dipole in the direction of its major lobe. It would not have the gain of the doublet, but simpler to erect in field. W2VS traps are available for 80 meters and up in two versions. 40-10 Meter Portable Dipole Phil Salas - AD5X ([email protected] (3) If a 40 meter antenna is close to a 15 meter hex, that can be a problem because 21 mHz is a third harmonic of 7 mHz and odd harmonics interact. The two arms. TAK-tenna 40 to 10 meter Multiband Antenna. BUT, remember, a dipole has a similar pattern, with peaks and nulls. A Zepp cut for the low end of 160-meters works on 80-meters, 40-meters, 20-meters, and 10-meters. This was done for a few reasons including 1) We believe that the dipole kit is much more versatile and will enable beginners to get. Here’s an easily transportable vertical antenna for 20 meters collapsible to 4 feet that costs about $2. I decided to install an 40 meter dipole in my attic space which is about 25 by 45 feet, and about 25 feet up from the ground. I used 1″ thin-wall PVC pipe, aluminum tape, and RG-8X coax. Let’s say we have a dipole with feed point R of around 65Ω, drawing a horizontal line from R=65Ω across the the blue line, and then dropping that horizontally we find that the electrical length needed is 40°, and Xl needs to be -27Ω. 15 should be about 0. This antenna offers a good operating range on both bands. Although this design has been around for a long time, it is only gaining popularity now due to the recent improvement in high power antenna tuners. endfedz ef-10/20/40 10m/20m/40m end fed dipole parts list part no. I wanted high efficiency 40 Meter antenna with low-angle radiation. Sloper antenna for both 40 and 15m bands cut into tower guy wire. Twenty meters designates the length of the particular radio wave used to transmit and receive voice and Morse code. The article offers information on a design featuring a matched coax fed antenna with performance similar to a full size dipole on to bands, 40 and 20 meters. I've used fan dipoles for many years both at home (75/160) and rattlesnake island (40/75/160). Whatis(aWindom(• Itis(an(offAcenter(fed(dipole(and(can(be(constructed(as(a(mulFband(antenna. Recently, members of Sacramento County ARES got together to build a 20/40 meter trap dipole antenna with a homemade balun. An Attic Coaxial-Cable Trap Dipole for 10, 15, 20, 30, 40, and 80 Meters John DeGood, NU3E [email protected] Sotabeams sells also antenna wire. My inverted-V at 40 ft. To find the half wave, divide that number by two. It competes in popularity with the "Half Size G5RV" from England. Here are some typical OCF dipoles that are successful designs 160-6 meter OCF antenna layout (using a double tuned stub for better 20 and 40 meter performance) Here is the 160-6 meter SWR graph using 200 feet of RG213 feed line and an average height above ground of 35 feet: 80-10 meter OCF antenna layout […]. Similarly on the same antenna, the same trap operating off resonance as a load with 400 watts of 3. An Attic Coaxial-Cable Trap Dipole for 10, 15, 20, 30, 40, and 80 Meters John DeGood, NU3E [email protected] Step-by-Step: With those measurement devices in mind, let's consider the big picture practical steps of trimming a dipole antenna: Determine the band and frequency range for which you desire the antenna trimmed. Example — 80 meters: If you are operating on 3. Using a 40 meter dipole for 15 meters has presented some problems. Time will tell how this effects local Tx/Rx on 80/75 meters however DX should improve some. Each is installed with its own feed line, at the correct height for low angle radiation pattern. band with 80 Meters. I used 1″ thin-wall PVC pipe, aluminum tape, and RG-8X coax. I decided to install an 40 meter dipole in my attic space which is about 25 by 45 feet, and about 25 feet up from the ground. A much better alternative to any of these three antenna designs is running the open-wire line from the center of a dipole all the way to a balanced antenna tuner, which was recommended by Louis Varney, G5RV himself. If the SWR is higher at the highest frequency than the lowest, then the outer section is too long. I have less tha 1. In some circles, a dipole antenna doesn’t get a lot of respect. The same would hold true for using that 40 meter dipole on 20 meters. The Best First Antenna, Hands Down; Worked for me! My first antenna was a 20 meter dipole cut to the middle of the General band out of 18 gauge insulated wire I picked up at Lowes. We are going to use an 80 meter ½ wave dipole for this This can be done with a base fed vertical antenna, but is. In practice, it may be difficult to obtain a good match on all bands. 1:1 SWR at the antenna connector of each Vertical. The coil is a bit over kill to just run 200 watts through it, but it was given to me. The gain is around 4 dBd on 40 mtrs, but it will seem much higher due to the very low angle, radiation pattern. endfedz ef-10/20/40 10m/20m/40m end fed dipole parts list part no. The OCF dipole presents a reasonably good match to the transmitter across multiple bands which are EVEN harmonics of the fundamental frequency, including 80, 40, 20, 10 and 6 m bands. 79 twinlead Quarter wave in space is: 17. was used for a couple years. This antenna is similar in construction to the 2-meter OFC sleeve dipole I built over 8 years ago, but it is a simple center-fed dipole. The antenna consists of a regular 40 meter dipole using a 1:1 balun at the feedpoint. 64 foot ground plane Three Quarter wave Vertical: 51. I settled on a 2 meter vertical dipole. • Radiating element will be a dipole that is ½ wavelength for the frequency. The 90-foot version offers the greatest bandwidth on the 75-/80-meter portions. alphadeltacom. The EZNEC model shown here is an approximately 13. "Everything works," it's all a matter of degree. I have found that element separation is important. 64 foot ground plane Three Quarter wave Vertical: 51. 12 meters is like 1. This was a fun project that gave us an opportunity to get some hands- on experience with antenna making. As you noted, it is also a good antenna for DX on 20m due to its relatively low takeoff angle. The total length of this dipole antenna, including the two traps, is only 43. 20-40 meter inverted "V" dipole questions. ' If only one half of it is used it becomes a 'half sloper. 000 Power Rating 2kw Antenna Lengths 10 Meters each leg 9 ft. The following photos and writeup are the results. Just thought I'd toss in one more agreement with the last two posts. , a 2-meter vertical, a 40-10 Meter Off Center Fed (OC F) Dipole, and a 10-meter rotatable aluminum dipole. Let's first calculate what we need. It would not have the gain of the doublet, but simpler to erect in field. 40-10 Meter Portable dipole Phil Salas - AD5X ([email protected] Solderless , crimped construction. 586 Mhz 3rd Harmonic Halfwave in space is: 34. I have the radio, power supply, and antenna tuner (if required) mostly narrowed down but am uncertain about antennas. Could I put out a decent signal on 40 if I placed an automatic tuner at the antenna end of my coax feedline?. The 80 meter wire turned out to be too short so only 20 and 40 meters are useful. Example — 80 meters: If you are operating on 3. This simply is not true! The radial system mitigates the ground return losses, which affect the efficiency of the antenna, but not its radiation pattern. As you noted, it is also a good antenna for DX on 20m due to its relatively low takeoff angle. An in-line balun takes care of potential feedline unbalance and radiation problems. 160 Meters each leg 126 ft. Comparing my dedicated 75, 40 and 20, I see them very much the same. I just ordered a Diamond Discone antenna for satellite stuff so it will probably be going on the tower soon also. VERTICAL ANTENNA. You can prove this to yourself by modeling the antenna with your favorite antenna modeling software. Many hams’ first choice of antenna is a half-wave dipole. If this does not present a problem and if you have the space this is the primier DX antenna for 40 and 75 meters!!!!! We are not limited to only 40/75 meter versions of this antenna. Many hams do quite well with dipole antennas that are electrically low; for instance, an 80-meter dipole strung between two trees at 50 feet (less than a quarter. With this arrangement, the antenna will work well on all bands 40 through 10 but it will only works as a EDZ on ten. This antenna proves no exception to that rule. A Hawaii-based Amateur Radio Antenna Blog focusing on the theory, design, and use of homemade antennas. K6IF/W6BDN 40 Meter Rotatable Dipole. I've used fan dipoles for many years both at home (75/160) and rattlesnake island (40/75/160). Plus two radial spreaders. They installed it on my roof top at 18’. Weighs less than two pounds and pulls high in the air with lightweight cord. Each is installed with its own feed line, at the correct height for low angle radiation pattern. The MMANA-GAL model of the K1POO antenna at 8m height shows that the antenna has a more complex lobe structure as the frequency increases. EF-10/20/40 MkII QRP End-Fed Dipole. The noise floor was at 0-super quiet so I figured it's because you have no 40 meter antenna dummy. 40 & 20 Meter- Fan Dipole- Half-Wave Amateur Ham Radio Antenna Made from high quality 16 AWG stranded insulated wire. My very first QSOs from here in Denver were to eastern Nebraska; Oklahoma; and Washington, on 20, 40 and 80 meters, so I am very pleased with that. Will be shipped out ASAP, please allow up to two weeks for delivery, thank you for your support. 40/20/10/6M,300W,OCFD UltraLite Dipole. I was unable to get an acceptable (<3:1) VSWR on 15 meters. The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun. Line Isolation / Choke Balun: A line isolation balun isolates the antenna elements from the coaxial transmission line so that power is radiated by the dipole antenna elements and not by the feed. INVERT VEE = 0 Foot 0. Outstanding performance on all bands with a tuner. For a 40/80 meter antenna, I printed 40 spacers. With that rig, I can tune the 80, 40, and 15 meters bands. It's a dipole fed off center with a 4:1 current balun at the offset feedpoint. The EMC Shop has experienced antenna design engineers available to design, develop, test antennas and review data utilizing cross antenna and cross lab results for in-depth evaluation to ensure the best performing and most efficient antenna is selected for product embedding. This coil came from a broadcast transmitter. Double Bazooka NVIS Antenna Calculator. "By design it has a good SWR only on 40/20/10m. ) long, it is too short to be resonant on either 30 or 40 m and presents a capacitive reactance at these frequencies. Only a few lucky hams have room for this type of antenna on 160 or 75 meters but on 10 meters the overall length is just 43 feet long! This is smaller than a 40 meter dipole. long dual-band resonant antennas. The Asymmetrical Hatted Vertical Dipole (AHVD) is an ideal Portable HF Antenna you can build yourself. One can use a tuner to "match" the antenna on 15-meters but the performance will not really be that good. 1:1 SWR at the antenna connector of each Vertical. My favorite amateur radio antenna for the HF bands 10- 20 meters is the Cubical Quad antenna. I have the monogap 20 meter ground mounted. 95 for the ends of the wires and at 20 cm. If this does not present a problem and if you have the space this is the primier DX antenna for 40 and 75 meters!!!!! We are not limited to only 40/75 meter versions of this antenna. The noise floor was at 0-super quiet so I figured it's because you have no 40 meter antenna dummy. 20 and 15 are important too. 15) gives a folded dipole with a length of 65. If the antenna. use the jetstream data sheet provided. For 15 and 10 meter at 3. It is an excellent all-around 40 meter antenna for those who don't have room for (or can't afford) a yagi, but want more than an inverted V. By John Portune W6NBC. The 4-Band antennas are OCF (off-center-fed), with a 23 foot leg and a 45 foot leg, totaling 68 feet. 2 Frequency in Mhz 14. For example, a 40 and 20 metre trapped dipole would have traps installed at the 20 metre points which would prevent the 14Mhz band, effectively shortening the antenna. The half-wave ham radio dipole is also the most common antenna used by amateur radio operators throughout the world. 285 with less than 1. 40 & 20 Meter- Fan Dipole- Half-Wave Amateur Ham Radio Antenna Made from high quality 16 AWG stranded insulated wire. Inverted-Vee Antenna 10 15. MFJ-347 Double T Pipe Mount With SO-239 Build A 80-6 Meter Mini Hamstick Dipole. length of dual wire‐stranded stereo speaker wire and. Vertical Dipole 12 17. The Buddipole™ - HFportable dipole antenna system, Welcome to the home of the Buddipole™, an hf/vhf portable dipole antenna system which is designed to be modular, versatile, and efficient. 25 lambda 0. 3 swr at either end of the band 80 meters at 3. I have also constructed the 20 meter version, just for fun, because 1) it is easy, 2) I was curious to see how well it performs, and 3) because I still had the coil core and coils of my first prototype 40 meter KGD. Off-center fed dipole can operate well on even harmonics of its lowest frequency, e. - 20 Meters each leg 17 ft. 8 into 468 gives 123. From the dimensions you gave, could the lengths actually be 33' and 8' for each leg? If so, that is what you have, a homebrew dual band dipole. I have built dozens of them, and continue to model, test and research more variations of them. 5" Package. The Fan dipole for 40/20/6m performs well. The EMC Shop has experienced antenna design engineers available to design, develop, test antennas and review data utilizing cross antenna and cross lab results for in-depth evaluation to ensure the best performing and most efficient antenna is selected for product embedding. When determining how long to make each leg of a Dipole antenna, dividing the frequency in MHz into 468 will give the overall length. The loop really, really cuts the mustard on 160, 80 and 40 meters compared to a dipole at the same height. qty description sub14004 1 10/20/40 meter ef matchbox 1406 1 20m radiator 34’ 0” 1402 1 20m tuning stub 1409 1 end insulator 14417 1 #10 split ring lockwasher 2814 1 #10 stainless hex nut 2815 2 #10 stainless flatwasher 32767 1 shipping box 1408 1 ef-10/20/40 manual. For a 40/80 meter antenna, I printed 40 spacers. It competes in popularity with the "Half Size G5RV" from England. We are going to use an 80 meter ½ wave dipole for this This can be done with a base fed vertical antenna, but is. These spreaders are used to space out the antenna wires on a fan dipole. I want to add dipoles for 80m, 15m and 10m. Dimensions Of The Finished Antenna You could do without a antenna analyzer if you build your six meter folded dipole antenna system with the following dimensions: ==> Six meter folded dipole made of 450 ohm ladder line, #16 7 strand copper clad steel wire : 8. Making it a resonant antenna for all bands from 80m to 6m (except WARC bands). In practice, it may be difficult to obtain a good match on all bands. Band Hopper III Multiband Portable HF Dipole Antenna System *** IMPORTANT NOTE: if you are using a Band Hopper with our 10m Compact Travel Mast, attach the antenna with a cable tie to the top of section 11 (counted from the bottom). 40-10 Meter W7FG True Ladder Line Open Wire Fed Dipole 65' Dipole 100' Feedline $99. The 90-foot version offers the greatest bandwidth on the 75-/80-meter portions. I have built dozens of them, and continue to model, test and research more variations of them. It is an excellent all-around 40 meter antenna for those who don’t have room for (or can’t afford) a yagi, but want more than an inverted V. CW 80- meter adapter is also available for the CW portion (3. This antenna is an excellent performer, and ruggedly built. Choose from top-brand HF Yagi, HEXX beam, and other rotatable antennas to meet your high-frequency needs. We designed and built this antenna to mount just below our tri-bander at about 70' on a crank-up tower. The RadioWavz DX (OCF) Windom is ideal for those of you who do not use a tower and beam. My last vertical antenna experience relevant to the Hex Array came from the MFJ-1792 antenna. One end goes straight into the rig, often with no feedline, and the other end in the air attached to something as high. The larger the wire, the wider the bandwidth. Put the antenna back together, hooked up the coax, and my neighbor and I raised the antenna once again. A loop fed in the southwest corner will have a few dB (3dB or more) gain favoring the northeast corner. We are going to use an 80 meter ½ wave dipole for this This can be done with a base fed vertical antenna, but is. An analysis of various installations has shown that an 88-foot dipole is too short to be a reliable antenna on 80 meters (or a 44 foot dipole on 40 meters) without some form of low-loss reactance compensation at the antenna feedpoint or very near the antenna. 20 and 15 are important too. 0 out of 5 stars 14. In a pinch it will even load up. qty description sub14004 1 10/20/40 meter ef matchbox 1406 1 20m radiator 34' 0" 1402 1 20m tuning stub 1409 1 end insulator 14417 1 #10 split ring lockwasher 2814 1 #10 stainless hex nut 2815 2 #10 stainless flatwasher 32767 1 shipping box 1408 1 ef-10/20/40 manual. and 30 meters other 6 are 10,15,20, 40,65, and 160. 80/40m Trap Dipole (VE3NCQ, you’re S9+20) Everybody who has heard me on 80m knows that I’ve been stuck using a compromised antenna for 80m. ' An EDZ' built for 20 meters is about 85' long. A 40M l/4 Vertical with Elevated Radials Original 40M dipole Simple Fan Dipole for 80, 40, 20 •An easy to build resonant antenna with a low elevation angle. This is a top-loaded 80/40 meter vertical which replaced my Butternut once I installed a tower with a beam, and no longer needed a vertical to operate above 40 meters. This horizontally polarized antenna is an extension of the horizontal loop antenna featured in The ARRL Antenna Book. The Feed and Phasing cables are added. 7 Mhz power still remains cold. 1 MHZ) full-wave loop antenna will also be resonant on: 20 meters ( +/- 14. Whatever the book say, in practice the inverted V does not come up to the standard of a dipole antenna. This is just a quick video of what I have setup for a 40/20 meter antenna. It covers the 80 meter through 6 meter Amateur Radio bands and can handle up to 100 watts SSB, 25 watts digital. I wanted to make a all band antenna without the long tail of a G5RV. Length L(meters) = 142. For 15 and 10 meter at 3. In production since early 2004; No tuner or counterpoise required, uses just one wire!. A Portable Twin-Lead 20-Meter Dipole With its relatively low loss and no need for a tuner, this resonant portable dipole for 14. The coil used is big enough to cover the 40 meter band as well. Multiband LOOP antenna made after the design by SP7LA for 80 - 40 - 30 - 20 - 17 - 15 - 12 - 10 meter bands with frequency ranges of 3500kHz to 3800kHz, 7000kHz to 7200kHz, 10100kHz to 10150kHz, 14000kHz to 14350kHz, 18068kHz to 18168kHz, 21000kHz to 21450kHz, 24890kHz to 24990kHz and 28000kHz to 29700kHz with overall length of 82. 25 lambda 0. New Home of the Force 12 Antennas. In my setup, the 40 meter antenna is more of an inverted V, while the 75 is pretty much a flat top dipole (this is at Rattlesnake island). 3 MHz) 10 meters ( +/- 28. Added an additional three or so feet to each length as the wound coils shortened each leg-wire of the antenna (with coil in place 40-meter length still needs to be 25-feet and 80-meter with coil in place still needs to be 38-feet in length). A Crappie Pole 20 Meter Dipole. a grid-dip meter. (• Windom(for(10(– 40(meters(shown. I have also constructed the 20 meter version, just for fun, because 1) it is easy, 2) I was curious to see how well it performs, and 3) because I still had the coil core and coils of my first prototype 40 meter KGD. The purpose of this project is to design a simple multiband vertical dipole antenna for 20 meters and above, with a tuner, that will provide gain and a circular pattern on the higher bands. The antenna has a separate dipole for each band and does not use any traps. It will supplement the big horizontal dipole by providing good omnidirectional coverage, with some gain, from 20 through 6 meters. Comparing my dedicated 75, 40 and 20, I see them very much the same. mast which holds three other antennas, viz. Close to 7-1/2 feet, a Slinky is a quarter wavelength at the upper end of the 40 meter ham, therefore a dipole antenna for 40 meters can be easily made from a pair of original Slinky's with pretty good transmission and reception results. KGD-20-FD: KGD DIPOLE FOR 20 MTRS. The antenna was placed in both the NVIS (Near Vertical Incident Skywave) mode where most signals are sent straight up which normally provides very good region-wide communications out to about 500 miles, and the. You will need a good ground system with an end fed quarter wave, but use two in a dipole for a nice shortened loaded dipole antenna. A Zepp cut for the low end of 160-meters works on 80-meters, 40-meters, 20-meters, and 10-meters. Short 42 foot long dual band 20/40 Meter dipole. DX-LB Low Band Dipole Covers 160-80-40 meters with an overall length of only 100 ft. It's a dipole fed off center with a 4:1 current balun at the offset feedpoint. Notice the difference in the pattern of this antenna and the curve for the dipole in figure 2. 5 for the FULL BAND on 20 meters. The spacers are made out of 1/2" PVC pipe, cut 7" long. The measurements below are for building a Double Bazooka Near Vertical Incident Skywave (NVIS) Antenna. The measurements below are for building a simple Dipole Antenna. The tuning of this antenna was very straightforward; I simply tuned the main element for the center of the 40 meter band and then adjusted the 20 meter stub for the center of the 20 meter band. It also supports my 80-160 meter fan dipole and a 40 meter delta loop, along with my B&W multiband folded dummy loader I mean inverted vee. 5-inch, 20 and 17 meters with a 3. wire lengths shown are for cw & phone center band. The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun. as of 2019. Short coax fed 42 foot long dual band 40/20 Meter dipole antenna. But 8 bands with one antenna and no tuner is pretty impressive and reports are impressive as well. Now you can operate the low bands on 80, 40, and 20 Meters with a true rotatable dipole that ll blend in with the sky!. Unfollow 40 meter dipole antenna to stop getting updates on your eBay feed. DX-LB Low Band Dipole Covers 160-80-40 meters with an overall length of only 100 ft. This QRP antenna uses a broadband matching network and a dual frequency half wave radiator. 16’ ¼ lambda 60 METERS = 62. Also, the efficiency is greater than a single wire dipole due to the six wire current distribution. The EMC Shop has experienced antenna design engineers available to design, develop, test antennas and review data utilizing cross antenna and cross lab results for in-depth evaluation to ensure the best performing and most efficient antenna is selected for product embedding. Based on the formula near the top of this page, I would need only 35 turns. Using a 40 meter dipole for 15 meters has presented some problems. The antenna is a Maxcon OCF-2K75-S Off Center Fed Dipole at 50 feet. This is a popular antenna design as the performance is very good across the HF bands and requires little or no tuning. I picked up a chassis-mount SO-239 from Radio Shack, and used an old, plastic cutting board from the kitchen for the insulators, and mount for the -239. This simply is not true! The radial system mitigates the ground return losses, which affect the efficiency of the antenna, but not its radiation pattern. The Asymmetrical Hatted Vertical Dipole (AHVD) is an ideal Portable HF Antenna you can build yourself. Total length of antenna in feet Open the dipole length calculator in a separate page. MFJ 80/40/20 Meter Rotatable Dipole A full legal limit efficient 80, 40, and 20-meter antenna that is shorter than a 20-meter dipole. The gain is around 4 dBd on 40 mtrs, but it will seem much higher due to the very low angle, radiation pattern. 5 for the FULL BAND on 20 meters. 40 & 20 Meter- Fan Dipole- Half-Wave Amateur Ham Radio Antenna Made from high quality 16 AWG stranded insulated wire. 80 Meter Off Center Fed Dipole sometimes known as a Windom, if DX is your goal then RADIO WAVZ brings you new technology at an affordable price. I picked up a chassis-mount SO-239 from Radio Shack, and used an old, plastic cutting board from the kitchen for the insulators, and mount for the -239. The performance is compromised surprisingly little. 5 on 80, most of 75, 40, 20, 17, 10 and 6. I built the antenna immediately and fell in love with it. 20 Meter CW Center Frequency: 14. Step-by-Step: With those measurement devices in mind, let's consider the big picture practical steps of trimming a dipole antenna: Determine the band and frequency range for which you desire the antenna trimmed. Is the tuning for 15 meter primarily tied to the 40 meter dipole, or, is it more spread out amongst all dipoles? For antenna shortening, what are the pros and cons of shortening in terms of cutting versus folding back on itself and twisting?. • A Dipole in free space is a 72 ohm antenna! - Proximity to earth changes the impedance - High dipoles are closer to 75 ohms - Low dipoles are closer to 50 ohms • Feedline SWR (and loss) depends on the match between feedline and antenna - Use feedline that matches the antenna • XMTR will reduce power if mismatched. The loop really, really cuts the mustard on 160, 80 and 40 meters compared to a dipole at the same height. 2 Frequency in Mhz 14. The two arms. The OCF dipole presents a reasonably good match to the transmitter across multiple bands which are EVEN harmonics of the fundamental frequency, including 80, 40, 20, 10 and 6 m bands. 60 foot ground radials Five eights wave Vertical is: 43. Multiband LOOP antenna made after the design by SP7LA for 80 - 40 - 30 - 20 - 17 - 15 - 12 - 10 meter bands with frequency ranges of 3500kHz to 3800kHz, 7000kHz to 7200kHz, 10100kHz to 10150kHz, 14000kHz to 14350kHz, 18068kHz to 18168kHz, 21000kHz to 21450kHz, 24890kHz to 24990kHz and 28000kHz to 29700kHz with overall length of 82. Make Offer - ALPHA DELTA MODEL DX-CC PARALLEL DIPOLE WIRE ANTENNA 80/40/20/10 METERS. HORIZONTAL LOOP ANTENNA CONSTRUCTION. Traps for different bands can be combined onto one dipole to create a single antenna tuned for maximum gain on all your favorite bands, from 160 to 10. 12 meters is like 1. Feeding the OCF dipole at a point that is one-third of its. An Attic Coaxial-Cable Trap Dipole for 10, 15, 20, 30, 40, and 80 Meters John DeGood, NU3E [email protected] "Everything works," it's all a matter of degree. A correctly designed trap dipole will have each frequency section of the antenna isolated from the others. 6 METERS ANTENNA · to achieve a resonant antenna design on 6, 10, 15, 20, & 40 Meters and · 6 Meter Horizontal Dipole Antenna Project by KK5ID. For 15 and 10 meter at 3. Since the resonant length of a given element in the presence of the others is not the same as a dipole by itself, tuning can be a tedious and difficult procedure. 40/20/10/6M,300W,OCFD UltraLite Dipole. Let’s say we have a dipole with feed point R of around 65Ω, drawing a horizontal line from R=65Ω across the the blue line, and then dropping that horizontally we find that the electrical length needed is 40°, and Xl needs to be -27Ω. This antenna has been working very well for me in spite of how close it is to the ground. I specifically wanted to work 20 and 40 meters, so a dipole with a 14. It received well on both bands. Yes, I've had lightning hit an antenna and yes I had to repair some damage. 8 into 468 gives 123. Easy to Install and Use KM5M on 23rd Apr 2014 The NI4L end-fed 40-6m dipole antenna is just about perfect for portable operation. MFJ 80/40/20 Meter Rotatable Dipole A full legal limit efficient 80, 40, and 20-meter antenna that is shorter than a 20-meter dipole. The Classic Numbers for All Types of Wire Antennas at HF. To support an antenna, I have no tower, and only two trees that aren’t too close to a house. ' An EDZ' built for 20 meters is about 85' long. 300 Ohm Twin Lead with the ends shorted is an option for even greater bandwidth. 25 lambda 0. I have also constructed the 20 meter version, just for fun, because 1) it is easy, 2) I was curious to see how well it performs, and 3) because I still had the coil core and coils of my first prototype 40 meter KGD. This QRP antenna uses a broadband matching network and a dual frequency half wave radiator. Alpha Antenna HexTenna™ Yagi [Hextenna_Yagi] - The HexTenna™ Yagi by Alpha Antenna® is a legal limit and full size portable 10-20 meter HF & 2 meter VHF Yagi that is deployable as a UHF/VHF/HF Vertical/Dipole HexTenna™. Radioteletype is used frequently on this band as well. The Shorty Forty Antenna can be put up in the space required for a 20 meter dipole. As you noted, it is also a good antenna for DX on 20m due to its relatively low takeoff angle. This antenna is similar in construction to the 2-meter OFC sleeve dipole I built over 8 years ago, but it is a simple center-fed dipole. 1/2 wavelength on 30 meters is 46 feet. 5 to1 balun hang-n-go. I do have some questions about noise and tuning. whip dipoles up 20 feet and half-wave dipoles for 40 and 75 meters. qty description sub7001 1 40 meter ef matchbox 701 1 40m radiator 65’ 6” 1409 1 end insulator 14417 1 #10 split ring lockwasher 2814 1 #10 stainless hex nut 2815 2 #10 stainless flatwasher 32767 1 shipping box 705 1 ef-40 manual 706 1 tuning stub endfedz are mono band matched antennas. placed somewhere between 40 and 20 percent from one end of a an antenna, instead of in the center. MFJ 80/40/20 Meter Rotatable Dipole A full legal limit efficient 80, 40, and 20-meter antenna that is shorter than a 20-meter dipole. I have built dozens of them, and continue to model, test and research more variations of them. Enter the desired operating frequency in megahertz to get a good starting length for a dipole in both feet and meters. Cushcraft achieved a major breakthrough in the development of an HF multiband vertical antenna that has been specifically designed for use with a tuner and amplifier. Two 1/4 wave ham sticks in a dipole configuration produce a 1/2 wave dipole antenna. This was our in! The flagpole kit came from Lowes and cost $29. Consider a 4 trap dipole for 20, 40 & 80. I currently use only wire antennas which work fine on 40 and 80 meters, but on the higher Bands, I need some gain. I printed enough to place these about 2' apart along the antenna. A trap design guide is provided below to aid multiband dipole construction. It works just fine and dandy on 20 meters as well but I'd rather have a dedicated 20 meter loop for 20 through 10 meters. 38' ½ lambda 0. Order by Paypal.