20 Meter Antenna Plans

At its design frequency, the antenna provides a forward lobe with a beamwidth so wide that it is nearly cardioidal. Being a half-wavelength on that band, the antenna pro-vides an efficient low-angle radiation pattern, with roughly a dB of gain over the shorter standard quarter-wave vertical. 092 wavelength long. 10, 15, and 20 Meter models are designed for mast or tower mounting. 24 - Tilted Folded Dipole Antenna. A 20 meter half square will function as a low 40 meter horizontal dipole with the ends folded down. For receive only, no balan or current choke is needed. • The G5RV was originally designed as a 3 /2 antenna for use on 20 meters. The GNSS antenna used for ground truth is shielded from the source’s antenna and is positioned at the null of the jammer antenna’s radiation pattern. Lengths are given in feet, inches and fractions of inches, and in meters. Great for travel!. Theory said this should work 10-20 meters. • 80 Meters - No significant difference in pattern - Gain about 0. 40 meters) “out of the clouds”. In addition, the elements are cut for this section of the six meter band. In other words, the RF choke will take up around 9. This unique design places full size elements along the boom in the same plane and produces amazing 2 element monobander performance on all 5 bands. 42MHz, Directional, 28dBic Gain with SMA Male. trap design used in two multiband antennas; one covering 80, 40, 20, 15 and 10 meters, and the other covering 80, 40, 17 Trap operation, all turns are used, in the con- ventional manner for a trap. 3- Elements YAGI Antenna for the 20- meter Band: By: Nikolay Kudryavchenko, UR0GT. I chose 58' for Mid 80 Meter Operation. This can be done using the radio's VSWR meter or an antenna analyzer. Minimum SWR. Since the sides of the square are equal, this means the finished antenna is approximately 5 feet square. The distance between one point to another adjacent point in a wave is known as the wavelength. 20 meters and 10 meters are mechanically between the 80 meter top and 40 meter bottom. (multiple wavelenghts). At 2 meters, a bit of reactance is introduced by this part, but compensated for by a small capacitor (C15) in series with it's input. For 40, 30, 20 and 15 Meters. Need a really simple antenna for better indoor 2 meter operation? Try this vhf delta loop you can hang in any window. Note that 44 + 25 equals about a quarter wave for 80 meters if used as an inverted L antenna. Monoband Beams for 12 and 17 Meters I designed a pair of driver-director Yagis for 12 and 17 meters using antenna-modeling software, in this case, NEC-4. The Navassa-5 is a five band / Multiband Yagi that interlaces 10, 12, 15, 17 & 20 meters on a single boom. A Simple, Effective Wire Antenna The NRY for 80 through 10 Meters Known as a broadside collinear curtain array, this antenna is simple to build, rakes in DX signals and has gain over a dipole on all the bands it covers! problem is that this antenna' s 20-meter feed- point impedance is very high. All hardware has. Admitting, the S-meter never went below S7, the base noise and QRM level was rather high. or even higher. The Top 5 Backyard Wire Antennas (in no order) by L. There is even a. 2 Meter (146 MHz) 3" Loop. A 6 meter vertical antenna must have at least 18 feet of active antenna to have 3 dB gain over a 1/2-wave dipole, and even then it might not be at the horizon, or may have coil losses, etc. 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 antenna was published in The ARRL Antenna Compendium, Volume 2 in 1989 (pages 58-60). If you want 75 Meter operation make it 57 ft long. 20 meter Moxon Beam that covers 14 to 14. 23 - Wideband Dipole for Receiving. Each way that I thought of, ended up requiring some type of guying system. A 3 kW 4:1 balun efficiently matches the antenna to 50 W. A full-size ( = ½λ) dipole antenna for the 20 mtr band spans about 10 meters (33 ft). Further information can be found at W9WIS’s web site. 8 dB lower - Much less SWR bandwidth - Greater feedline loss away from resonance Build or Buy a Short Dipole? • Designing a Shortened Antenna CT1EOJ QST Oct 2003 • Model it in NEC - Tweak the design for multiband coverage • Buy from Barry, KU3X, Hypower Antenna. This formula takes into consideration the capacitive "end-effect" from insulators which shortens the physical length requirement for the equivalent electrical length. I used a 100 ft roll of 18 gauge twin speaker wire. A 3 kW 4:1 balun efficiently matches the antenna to 50 W. Graphics by G8ODE DEC 2010 iss 1. 6 Ft) rg58 Coax Cable SMA Male to SMA Female Low Loss RF Jumper Two-Way Radio Applications Pure Copper 50 ohm SMA Antenna Extension Cable. 6 Ft) rg58 Coax Cable SMA Male to SMA Female Low Loss RF Jumper Two-Way Radio Applications Pure Copper 50 ohm SMA Antenna Extension Cable. Light Beam Antenna & Apparatus, LLC offers a variety of compact, efficient, and stealthy solutions. See you on the radio. 333 feet long. The 20 meter dipole extends the full length of the space and the last 3 feet or so is drooped vertically at the end wall. 10 Meter 117. He squeezed-in all possible efforts into his retiring years to dedicate his time in amateur radio. Antenna length. antenna I have on my tower is dramatic. DIY Magnetic Loop Antenna by Owen KF5CZO Do you live in a neighborhood with a restrictive antenna policy and despair of having a useful HF antenna? Can you solder or know someone who can? A magnetic loop antenna may be the answer and they are not as difficult to build as you might think. The basic formula for determining the length of a center fed, half-wave wire Dipole or Inverted Vee antenna is:. The short stubs on each antenna are strategically sized and located to permit more flexibil- ity in adjusting the resonant frequencies of the antenna. " B-Square Engineering is the first to offer a Terminated Folded Dipole antenna, truly optimized for amateur radio use. Electromagne2c' Wave'Polariza2on' • Electric'and'magne2c'waves'are'at' right'angles'to'each'other' • Magne2c'wave'dissipates'within'a' few'wavelengths'of'antenna. Plans for a 20 Meter Yagi Antenna is a curation of 17 resources about , 2 Element Yagi, Monoband Yagi for 20 meters, 2-Element-Yagis for HF, PV4 4 element Yagi antenna, 5 element yagi for 20 Meter band. Prices are in US Dollars (USD). Thanks in anticipation. Dipole Antenna Length Calculator. These designs invariably sacrifice forward gain and pattern quality for wide SWR bandwidth. Since 20 meters covers the frequency range of 14. There is even a. 8 dB lower - Much less SWR bandwidth - Greater feedline loss away from resonance Build or Buy a Short Dipole? • Designing a Shortened Antenna CT1EOJ QST Oct 2003 • Model it in NEC - Tweak the design for multiband coverage • Buy from Barry, KU3X, Hypower Antenna. As the "counterpoise" itself approaches a half wavelength, the impedance approaches 5000 ohms. 20 meters and 10 meters are mechanically between the 80 meter top and 40 meter bottom. 88) should also work well. As the late spring and summer months heat up, six meters comes alive. The Half Square antenna is a wire antenna with two vertical radiators fed in phase. The 2 Meter antenna - A Cycloid Dipole: For the 2 meter beacon we started using a 2 meter J-pole - but in a service where most people listening were likely to be using horizontally polarized antennas, this was not considered to be ideal. The closeness of the MURS and 2-meter bands make it sometimes possible to use the same antenna on both the VHF bands. 46 dBi gain, which is about 3 to 3. The first thing I learned was the while resonant on 20 ,I was able to use an internal tuner (Icom 756P3) and put out a heck of a signal on 15/12/10 meters. The legs give this piece a light, airy feel, while strong joinery keeps it stable and sturdy. 5 mm Here is how to make such a helical Antenna. Jerry, K5OE: Home Brew Amateur Antennas. impedance of 50 ohms with a half wave length antenna, and the capacitor should have the ability to handle the R. WIKIPEDIA, The Last Word on Antenna Design zBuilt RG-8 Coax Stub and trimmed until 20 meters tuned, measured value. Our flagship model, The Two Meter J-Pole Antenna comes in two different configurations, either as a one piece antenna for base station use, or as a two piece breakaway model great for portable operations. It's got everything you want and more 17cm long for extension u. They are affected by height above the ground and surrounding objects. Over 60 QSOs with JA1RZD on 20 Meters in the last six months attests to the efficiency of this antenna. Folded Marconi Tee Antenna 8 10. The antenna is constructed much like an ordinary Dipole antenna but with 5/8 Wavelength Elements matched with an added Impedance Matching Section of balanced feed line. So the entire length of the antenna is 460 divided by the frequency in MHz (7. The EZNEC model indicates resonant dips at 5. Double Bazooka Coaxial Dipole Antenna Info There is a lot of controversy surrounding the Double Bazooka Coaxial Dipole. A Simple, Effective Wire Antenna The NRY for 80 through 10 Meters Known as a broadside collinear curtain array, this antenna is simple to build, rakes in DX signals and has gain over a dipole on all the bands it covers! problem is that this antenna' s 20-meter feed- point impedance is very high. 468 ÷ freq (mHz) = Length (feet). Performance. Many 6-meter beams, both homebrew and commercial, are designed to work to 51 or even 52MHz. Read the Omni FAQ page. Some two-way radios have the feature of Voice Activated Transmit functions, VOX. Worked ALL of the 3077 COUNTIES from 2500 Counties! SEE PHOTO of N6HH’s Rig. Buy 20 Meter Half Wave Dipole Antenna with W2FMI 1500 Watt Balun: Radio Antennas - Amazon. Five elements are active on 20 and 15 meters and all six are working on 10 meters! This is the hottest performing tribander on the market! A dual driven element (log cell) creates a rig pleasing, flat match, and broad gain & front to back curves across 10, 15, and 20m. My design is similar to his design in that I use 4 inch diameter PVC pipe as the coax winding form. Package content : 2 x RP SMA to IPX Cable. This shortened easy-to-build vertical, with no-radials, is made from surplus military camouflage poles. The graphs show the devastating difference between the two aerials as the frequency is varied around the reference 7. Multiband Tuned Doublet Antenna 14 21. If the unblock fails you will need to contact the server owner or hosting provider for further information. UR0GT - Match is used for matching the antenna with a coaxial cable PDF file, 1. Design of Yagi UDA Antenna For good efficacy and directivity for reception on radio spectrum, we need a good Yagi-UDA antenna. In other words, the RF choke will take up around 9. A half wave antenna's radiation peak angle is 20 degrees. The ¼ Wave Droopy Ground Plane 2 Meter Ham Radio Antenna Robert Richardson Emergency Communication 40 In the past we’ve talked about the many benefits of Ham Radio , and how every good survival plan should include some type of emergency communications equipment. In fact, all of the components (save, perhaps, the antenna connector) can be purchased at a DIY store. The revolutionary COMPACtenna 40mTHRU440 uses a patented design which includes magnetic-field-enhancement. The W5GI Multiband Mystery Antenna is a fundamentally a collinear antenna comprising three half waves in-phase on 20 meters with a half-wave 20 meter line transformer. ) Buckmaster 7-Band OCF Dipole Antennas are 135 feet (41 meters) long and work on 80, 40, 20, 17, 12, 10, and 6 meters. The closeness of the MURS and 2-meter bands make it sometimes possible to use the same antenna on both the VHF bands. Amazing six band coverage includes: 40, 20, 10, 6 plus 2 meters and 440 MHz! Power capacity is 100 Watts 40 through 6 meters, 85 Watts 2 meters and 50 Watts 440. Adding another joint would be trivial however. (multiple wavelenghts). Simple DIY Stealth Apartment Antenna for HF February 7, 2010 Scott Leave a comment General , RF (Radio Frequency) Warning : This post is several years old and the author has marked it as poor quality (compared to more recent posts). Basically, this is a coil in the coax feeding the antenna as close to the feed point as possible. The spacing between the wires are not critical, as long as the spacing between the wires are close together compared to the wavelength. The center pin of the coax is attached to one end of the antenna and the shield to the other end of the antenna. Using an impedance transformer resonant on 40 meters, the dipole will produce mostly omni-directional vertical radiation and work nicely for contacts out to 500 miles (800km)or so. Base stations are a great way to stay connected, especially during an emergency. After having a great deal of success with a 20m moxon at my QTH, I decided to build a portable version, based on help from The Moxon Antenna Project by KD6WD. In the evening hours on 40 m, the antenna was "too good", because the commercial broadcast stations came in so strong that I only heard cross modulation signals, and hardly any signals from amateur stations. My work surface was the silly plastic table, which served mostly as a place to set stuff while I searched for tools and hardware. You'll find that the 5/8 wave antenna's angle of radiation is just 16 degrees making it an even better dx antenna. Wire antennas need to be made a bit long and cut to resonance. Dipole Antenna Calculator. Thus, I didn't bother to make a second joint in the arms and the arms are longer overall than Budd's original design. The Mosley "Quality of Antenna Excellence" has become a standard to the industry. and figure 10. After living 20 years in a house with an aggressive HOA enforcing CC&Rs that prohibit all outside antennas, I'm moving to a house out in the country on 10 acres with no HOA and no CC&Rs. The forward gain is down from a full size 2-element Yagi only by about 0. If you follow the step-by-step instructions from "RC286", you should have a working 40/20 meter dipole antenna in a few. We're talking about "reasonable" heights on a given band as discussed in the antenna literature. Try not to damage the rivet. This is over 10,000 miles. It's fed with the same feedline and initial indications are it works well. 1 MININEC and NEC-2 would have been equally satisfactory. This shortened easy-to-build vertical, with no-radials, is made from surplus military camouflage poles. An Overview of the Underestimated Magnetic Loop HF Antenna It seems one of the best kept secrets in the amateur radio community is how well a small diminutive magnetic loop antenna can really perform in practice compared with large traditional HF antennas. If you want it to work properly, you will need a means of measuring SWR, some trial and error, a little patience and at least half-a-brain to build this. I use 10 feet of thin rg174 as a feed/counterpoise, so I didn't want high swr for that reason, as well. - Portable Vertical Antenna for 75m and 40m makes up a compact 28 feet high antenna. One end goes straight into the rig, often with no feedline, and the other end in the air attached to something as high as you can find. Accutane Cost Per Pill - Free Worldwide Shipping. But my old CB base antenna I had is long gone and I had always wanted to see how a vertical dipole antenna would work. A Four-Element 20-Meter Beam The four-element quad at has a driven element (second from left in this view), reflector, and two directors. Features of the K0WA 40 meter verticle. The material of the coil can be either solid copper wire or silver plated copper wire. In the sprit of keeping costs low, a PCB-mount type of DPDT general-purpose relay was chosen. › 20 meter band hf antennas The 20-meter or 14-MHz amateur radio band is a portion of the shortwave radio spectrum, comprising frequencies stretching from 14. DX Engineerings 300 ohm line (VF=0. All 6 antennas should range between 20 and 90 ohms with the ends at 10 ft. It received well on both bands. 35 MHz you can use a few algebraic formulas to compute antenna sizes. Monoband Beams for 12 and 17 Meters I designed a pair of driver-director Yagis for 12 and 17 meters using antenna-modeling software, in this case, NEC-4. (The lengths of the rope supports are misleading in the diagram, by the way. Refer to Figure 3 for the dimensional key. The most common HF Yagi today is a three-element design (a reflector, a driven element, and a director) that works on three popular ham bands (20, 15, and 10 meters) and so is called a tri-bander. The basic formula for determining the length of a center fed, half-wave wire Dipole or Inverted Vee antenna is:. The antenna also needed to be capable of handling 50 watts at 100% duty cycle for digital operation as well as 100 watts of SSB. Probably the best know antenna on our 11 meter band ! Everyone has used this type in the past or will use it somewhere! Although the half wave vertical comes along with various names the PRINCIPLE is all the same. The average center frequency of 40 meters is 7. A Simple, Effective Wire Antenna The NRY for 80 through 10 Meters Known as a broadside collinear curtain array, this antenna is simple to build, rakes in DX signals and has gain over a dipole on all the bands it covers! problem is that this antenna' s 20-meter feed- point impedance is very high. RD Bentley. Dipole antenna basics Current & voltage Half wave dipole Folded dipole Short dipole Doublet Dipole length Dipole feeds Radiation pattern Build HF ham dipole Inverted V dipole FM dipole design The length of a dipole is the main consideration for determining its operating frequency. 86` diameter (9`circumfrence) loop for 20 meters with spiral wrapped 3" diameter pool noodles. One of mine weighs about 4 pounds. With the addition of a tuner, it can be used on several bands. If one were to forgo 160 meter (1. Plots are with the actual trapped tri-band EFHW. Being the crafty maker type, I wanted to build my own antenna. With a length of 11 meters or more additional guy wire could be used. This was our in! The flagpole kit came from Lowes and cost $29. I was inspired by George Badger, February 2008 QST - “The W6TC DX Loop”, and Les Moxon, “HF Antennas for all locations”, to create the loop in a space between two trees in my yard. 15 meters works with a tuner as a 3/2 wave gain antenna, from the 40 meter antenna. I added an additional element to my 30 meter vertical mount for 17 meters. Conceptually, the multi- band quad is a simple antenna, with separate driven and reflector loops for each band. The SE-20M can be also be setup for 17 Meter operation by resetting the reflector and element spacer settings with an VSWR of 1. Government as a radar antenna. Must register, but it’s free. The Navassa-5 is a five band / Multiband Yagi that interlaces 10, 12, 15, 17 & 20 meters on a single boom. This is the perfect antenna for a Tech Class Operators or anyone desiring to work 6 or 10 meter band and still have the benefits of a beam over a wire. And, the impedance and reactance are perfect! Below is a quarter wave ground plane antenna I made for 23cm, 1296MHz which is made from off-cuts of household mains copper wire and a scrap BNC socket from the junk box. 4 MHz to 14. It may sound and looks like a G5RV but it is a substantially different antenna on 20 meters. Folded Marconi Tee Antenna 8 10. 4-Band antennas cover 40, 20, 10, and 6 meters, with no tuner required! 12 meters may also work on the 4-Band 300 watt model. Depending on the 2 meter and 70cm frequencies you choose for tuning your antenna, you might have to compromise a little. Granted, every antenna is a compromise and a flag pole antenna is no exception. There is even a. On this page I give details of how to build two different versions of the Double Bazooka Antenna. Their flexible mounting arrangement makes using them so easy!. by Gene Preston, K5GP I read Rick Littlefield's article in the June 2008 issue of QST on off center fed dipoles and was intrigued by the idea that the antenna could be extended to cover 80 meters. TAK-tenna 80 to 6 meter Multiband Antenna. 25 - Right Angle Marconi Antenna. Jeff is the author of DXing on the Edge, a book dedicated to 160 meter history, operation, and equipment (available from the ARRL). Reenter N6RY and the extended double Zepp. A dipole design for the 20-meter band is an efficient and inexpensive antenna for the novice and veteran ham enthusiast alike. The secondary is the main loop, and is the actual antenna. Test/Site Conditions for our Quarter Wave Sloper vs Inverted-V Dipole Because of the above stated variables we wanted to test these antennas over the. The Moxon Antenna, designed by Les Moxon (SK), is a compact two element beam antenna with about dbi of gain and a front to back ratio. 5 and 6 for similar designs. Bow-Tie Dipole Antenna 13 19. Object of the design: There are many designs and information available on the net concerning " Magnetic Loop Antennas". If the antenna had to be brought down to adjust its length I wanted to do it before I secured the cables and finished the installation. I used an antenna-modeling pro-gram called AO, which stands for Antenna Optimizer. power handling 3kw cw,6kw ssb. A small turning radius. 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. Larry Banks, W1DYJ 1Notes appear on page 40. If the unblock fails you will need to contact the server owner or hosting provider for further information. 20-Meter(65. Electrically Short Antennas-The shorter the antenna, the lower the Rr -A Hustler 6BTV 80/40/30/20/15/10 meter vertical is 24 feet tall -On 80 meters, it is only 0. 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. 4-Band antennas cover 40, 20, 10, and 6 meters, with no tuner required! 12 meters may also work on the 4-Band 300 watt model. This Field Day Vertical Antenna project is the result of many years of attending various field day sites and realizing that what was needed is a simple, easy to assemble vertical antenna. Mosley offers New Ham, Customer Loyalty, Veteran/First Responder, Club Station, and multi-kit discounting. • Radiating element will be a dipole that is ½ wavelength for the frequency. When optimising a design over a narrow bandwidth, fewer elements are needed. Buy 20 Meter Half Wave Dipole Antenna with W2FMI 1500 Watt Balun: Radio Antennas - Amazon. The Comet H-422 is a 4-Band (10/15/20/40m) rotatable dipole antenna. λ = 234 / F MHz (Feet) or 1/4. This version will give us 40 meters, 20 meters, 15 meters, 10 meters and 6 meters without an ATU. A half wave antenna's radiation peak angle is 20 degrees. The Isotron Antenna. Dipole antenna basics Current & voltage Half wave dipole Folded dipole Short dipole Doublet Dipole length Dipole feeds Radiation pattern Build HF ham dipole Inverted V dipole FM dipole design The length of a dipole is the main consideration for determining its operating frequency. This was our in! The flagpole kit came from Lowes and cost $29. This unique design places full size elements along the boom in the same plane and produces amazing 2 element monobander performance on all 5 bands. • It was used as a multi-band antenna because when fed with ladder line (not coax!) it is easy to match the on any band from 80m to 10m • A G5RV used as a multi-band antenna should be fed with ladder line. Accutane Cost Per Pill - Free Worldwide Shipping. Antenna Installation At this time, my plans are to place insulated wires for a multiple-band single-feed half-wave dipole on the roof. Enter the desired operating frequency in megahertz to get a good starting length for a dipole in both feet and meters. I've built several variations of this design for 80-10 meter coverage. However if like me you're faced with a small lot or perhaps in need of a stealth multi-band antenna or just want to get on 80 or 160 meters with something that works!. I proceeded to make a very heavy dipole from copper pipe, akin to the type used for J-poles. Solve Virtually Any Restricted Space Problem - 40 Meter Isotron only 22 inches x 16 inches x 15 inches! Easy, Quick, and Simple Installation; Tunes & Performs Without Radials or Antenna Tuners; Handles Up to 1000 Watts PEP. 20 meter quarter-wave vertical antenna experiment Not content with attempting to understand and build 40 and 80 meter verticals, I’ve decided to build a 20 meter version tonight. Admitting, the S-meter never went below S7, the base noise and QRM level was rather high. High Performance 40 Meters Vertical. The Carolina Windom is essentially an off-center fed dipole (OCFD) that uses a portion of its feed line as a vertical radiator. AV-12AVQ 13 foot 10/15/20 Meter HF Vertical Antenna w/ 1500W PEP View PDF ; AV-14AVQ 18 foot 10/15/20/40 Meter HF Vertical Antenna w/ 1500W PEP View PDF ; AV-14RMQ Roof Mount Kit for AV-18VS, AV-14AVQ, and AV-12AVQ View PDF ; AV-18AVT 10/15/20/40/80 Meter Vertical Radiator Antenna View PDF. The primary is the small inner loop that is 1/5 of the size of the main loop. Antenna was originally a 66 foot (22+44 feet) horizontal with 25 feet of 450 ohm LL vertical. The MFJ-1890 is a lightweight aluminum antenna designed to operate in the 10 meter band and we had hoped that with a little messing around we could get it to tune to the 11 meter cb band. - Portable Vertical Antenna for 75m and 40m makes up a compact 28 feet high antenna. In other words, the RF choke will take up around 9. There more good information here than anywhere! www. However, I'm getting itchy feet to try another antenna. How to make a Simple Dipole Antenna It is very easy to create a simple 1/2 wave dipole, all you need is some lengths of wire such as the core of some mains flex or even a straightened out metal coat hanger, some co-ax cable and a connector for your scanners antenna input (usually BNC or SMA). In order to get an idea of the right place to start, certain formulas are generally accepted. 20m Elevated Vertical Antenna - G8ODE NOTE: - The antenna wire is cut to the length calculated by the formula ; 1/ 4. A full-size ( = ½λ) dipole antenna for the 20 mtr band spans about 10 meters (33 ft). Building the 6 Meter Moxon Antenna See more. Antenna Installation Best Practices. WIKIPEDIA, The Last Word on Antenna Design zBuilt RG-8 Coax Stub and trimmed until 20 meters tuned, measured value. Its RF cable is also guided away from source’s antenna before entering the equipment in the vehicle. HORIZONTAL LOOP ANTENNA CONSTRUCTION. The Carolina Windom is essentially an off-center fed dipole (OCFD) that uses a portion of its feed line as a vertical radiator. 2:1 on 15, 20 and 40 meters. You can use a dipole on something other than its design frequency, but you will need to use an ATU and the performance will not be very good. The Beam Antenna Handbook by Bill Orr, W6SAI, has some very good designs for yagi antennas. Used a G5RV for years then had a break of some 20 years. 12-Oct-2019-PM : Search For 20 Meter Beam Antenna Plans. It's fed with the same feedline and initial indications are it works well. 9 dBi gain and you put 100 watts into the antenna, it will behave like 1548 Watts in the forward direction. A half wave antenna's radiation peak angle is 20 degrees. The orig­i­nal Jet­stream Multiband 80 - 10 Dipole nev­er had cov­er­age of th­ese bands. Building the 6 Meter Moxon Antenna See more. Minimum SWR. I like to use a home made current choke to keep RF from coming back on the feedline. Plan that extra length into your overall coaxial line between your antenna and your transmitter or antenna tuner. The photo to the right is an example of how the antenna may be supported with minimal holes or damage to the wall. Now, I wanted to build a similar antenna for 20-Meters, one of my favorite DX bands. This antenna normally has about a 3 DB gain over a 1/2 wave center fed dipole. 5 inch pvc spacers. One of my goals was NOT to make something that I would walk around with, I was after more of a campground antenna for my K1. To remedy the narrow bandwidth I used a bowtie dipole antenna for 10 meters. Example: To design a T2FD for the center of the 90 meter band (3300 kHz) and up:. 8mm, Coil length = 13mm The groundplane stub between last turn and solder stub = 4. 060 MHz and 442. I disassembled the antenna on Monday and stored it for future use. ), with a model 3000W 4:1 ratio balun. However, I'm getting itchy feet to try another antenna. 40 Meter Mini-MOXON Beam Antenna for many years and the decision for 20 meters and up was easy, but what to do been the first to publish a design with his. Figure 3 shows my 4 element quad built with old Moonraker 4 parts on a 40 foot tower. Delta Fed Dipole Antenna 13 18. Similarly on 40, the 40 meter traps isolate the outer sections and the 20 meter traps are used as loads, and on 80 no traps are on resonance, they are all used as loads. Also have you made any measurements of the gain and directivity of the antenna for the 20,15 and 10 meters. In other words, the RF choke will take up around 9. The SWR on 40, 20, and 15 meters is flat across the entire band. The Top five list contains a few antennas that if you have the room for them perform very well. My work surface was the silly plastic table, which served mostly as a place to set stuff while I searched for tools and hardware. Any reuse or redistribution of the contents of this website are strictly forbidden without authorization from MFJ Enterprises, Inc. This allows the extremely short antenna to perform amazingly well for its height. After a few months of pondering how to build a simple pull-up vertical collinear antenna, I think I've finally got it! The motivation for such a design is the fact that I have tall trees for a support and can actually pull such an antenna up into the trees to 100 ft. It received well on both bands. The impedance of this antenna is around 300 Ω, so you may want to use a transformer or a λ/4 long piece of 120 Ω coaxial cable to match this impedance to 50 Ω. Figure 1 — A comparison of the lower radia-tion angle and greater gain of the Moxon (red) compared to the dipole (blue). 180 Mhz and has a. With a length of 11 meters or more additional guy wire could be used. He squeezed-in all possible efforts into his retiring years to dedicate his time in amateur radio. Least you now have steam coming out of your ears, let me explain why. , tune) by simply adjusting the length of the tubular elements. ) Listing on the vertical is still very noisy. Performance of this antenna is very close to that of a classical monoband Yagi. construction plans for a portable antenna. The BIG Loop is for those like me, who want an EFFICIENT antenna to use in a small space from 20 meters downward past 60 meters and with low chance of it being accidentally discovered. This might be a good design for the AMer who lives in the central part of the USA and wants to put a better signal into both coasts with a minimum of effort. 100 MHz trap would be needed. Satellite communications typically involve a VHF uplink in the 2 meter band, and the azimuth & elevation of the receive antenna on the satellite is constantly changing, making c-pol ideal for best illuminating…. Minimum SWR. Soon after completing this contact she thought of a more objective test, namely to check PSK Reporter after test transmissions using each antenna. This is roughly 64 feet 4 inches. It's an 1/8 wave vertical on 160 meters also. Enter the desired operating frequency in megahertz to get a good starting length for a dipole in both feet and meters. If anyone has tried a G5RV in 46 ft of garden you will know that performance is not that great, and the “½ size” G5RV is completely useless on 80 meters. I specifically wanted to work 20 and 40 meters, so a dipole with a 14. Works great and gives several extra bands besides the 80/40/20/10 meters using Kenwood with. The large diameter yields broadbanded coverage of the 80 Meter Band. Start with cutting the radiating and reflecting elements. The diagram above depicts the 17 and 20 meter delta loops setup at my QTH. It will supplement the big horizontal dipole by providing good omnidirectional coverage, with some gain, from 20 through 6 meters. The cheapest way I have found to build this antenna is to find an old Moonraker 4. I put up another se­parate du­al band an­ten­na for the new bands, now that I had a rig (FT-950) that cov­ered them. The tuning process is the same as for the 40/80 dipole, excpet the 20 m wires are trimmed first to an SWR of 1. No ground plane or counterpoise is needed. It is a design that performs well and exhibits low input impedance, making it ideal for use with ham equipment without the need for. Can be matched to coax for single band operation. Prices are in US Dollars (USD). 5; Interesting observation was the antenna performed well on 6m. The noise was almost overwhelming the signal that I had to switch to the Endfed on receiving and switch back to the Taktenna for transmitting. My procedure involved two steps: creating a basic design with a uniform-diameter. So in this case, we want to build an antenna for 6 meters, 50. See Fig­ure 8 for the SWR curves. It is a directional antenna that provides great performance. Compact half-square for 40m band. The plan was to put up a one wavelength square loop for 20 meters in the diamond configuration, and a delta loop for 40 meters with a common feedpoint. I proceeded to make a very heavy dipole from copper pipe, akin to the type used for J-poles. Home of the AM Press/Exchange, The AM Forum (the largest BBS of it's kind),and The AM Classifieds, Photos, Audio, and technical information. Big 2 1/8 inch bottom section tapers to 1/2 inch at the top. The fact-checkers, whose work is more and more important for those who prefer facts over lies, police the line between fact and falsehood on a day-to-day basis, and do a great job. Today, my small contribution is to pass along a very good overview that reflects on one of Trump’s favorite overarching falsehoods. Namely: Trump describes an America in which everything was going down the tubes under  Obama, which is why we needed Trump to make America great again. And he claims that this project has come to fruition, with America setting records for prosperity under his leadership and guidance. “Obama bad; Trump good” is pretty much his analysis in all areas and measurement of U.S. activity, especially economically. Even if this were true, it would reflect poorly on Trump’s character, but it has the added problem of being false, a big lie made up of many small ones. Personally, I don’t assume that all economic measurements directly reflect the leadership of whoever occupies the Oval Office, nor am I smart enough to figure out what causes what in the economy. But the idea that presidents get the credit or the blame for the economy during their tenure is a political fact of life. Trump, in his adorable, immodest mendacity, not only claims credit for everything good that happens in the economy, but tells people, literally and specifically, that they have to vote for him even if they hate him, because without his guidance, their 401(k) accounts “will go down the tubes.” That would be offensive even if it were true, but it is utterly false. The stock market has been on a 10-year run of steady gains that began in 2009, the year Barack Obama was inaugurated. But why would anyone care about that? It’s only an unarguable, stubborn fact. Still, speaking of facts, there are so many measurements and indicators of how the economy is doing, that those not committed to an honest investigation can find evidence for whatever they want to believe. Trump and his most committed followers want to believe that everything was terrible under Barack Obama and great under Trump. That’s baloney. Anyone who believes that believes something false. And a series of charts and graphs published Monday in the Washington Post and explained by Economics Correspondent Heather Long provides the data that tells the tale. The details are complicated. Click through to the link above and you’ll learn much. But the overview is pretty simply this: The U.S. economy had a major meltdown in the last year of the George W. Bush presidency. Again, I’m not smart enough to know how much of this was Bush’s “fault.” But he had been in office for six years when the trouble started. So, if it’s ever reasonable to hold a president accountable for the performance of the economy, the timeline is bad for Bush. GDP growth went negative. Job growth fell sharply and then went negative. Median household income shrank. The Dow Jones Industrial Average dropped by more than 5,000 points! U.S. manufacturing output plunged, as did average home values, as did average hourly wages, as did measures of consumer confidence and most other indicators of economic health. (Backup for that is contained in the Post piece I linked to above.) Barack Obama inherited that mess of falling numbers, which continued during his first year in office, 2009, as he put in place policies designed to turn it around. By 2010, Obama’s second year, pretty much all of the negative numbers had turned positive. By the time Obama was up for reelection in 2012, all of them were headed in the right direction, which is certainly among the reasons voters gave him a second term by a solid (not landslide) margin. Basically, all of those good numbers continued throughout the second Obama term. The U.S. GDP, probably the single best measure of how the economy is doing, grew by 2.9 percent in 2015, which was Obama’s seventh year in office and was the best GDP growth number since before the crash of the late Bush years. GDP growth slowed to 1.6 percent in 2016, which may have been among the indicators that supported Trump’s campaign-year argument that everything was going to hell and only he could fix it. During the first year of Trump, GDP growth grew to 2.4 percent, which is decent but not great and anyway, a reasonable person would acknowledge that — to the degree that economic performance is to the credit or blame of the president — the performance in the first year of a new president is a mixture of the old and new policies. In Trump’s second year, 2018, the GDP grew 2.9 percent, equaling Obama’s best year, and so far in 2019, the growth rate has fallen to 2.1 percent, a mediocre number and a decline for which Trump presumably accepts no responsibility and blames either Nancy Pelosi, Ilhan Omar or, if he can swing it, Barack Obama. I suppose it’s natural for a president to want to take credit for everything good that happens on his (or someday her) watch, but not the blame for anything bad. Trump is more blatant about this than most. If we judge by his bad but remarkably steady approval ratings (today, according to the average maintained by 538.com, it’s 41.9 approval/ 53.7 disapproval) the pretty-good economy is not winning him new supporters, nor is his constant exaggeration of his accomplishments costing him many old ones). I already offered it above, but the full Washington Post workup of these numbers, and commentary/explanation by economics correspondent Heather Long, are here. On a related matter, if you care about what used to be called fiscal conservatism, which is the belief that federal debt and deficit matter, here’s a New York Times analysis, based on Congressional Budget Office data, suggesting that the annual budget deficit (that’s the amount the government borrows every year reflecting that amount by which federal spending exceeds revenues) which fell steadily during the Obama years, from a peak of $1.4 trillion at the beginning of the Obama administration, to $585 billion in 2016 (Obama’s last year in office), will be back up to $960 billion this fiscal year, and back over $1 trillion in 2020. (Here’s the New York Times piece detailing those numbers.) Trump is currently floating various tax cuts for the rich and the poor that will presumably worsen those projections, if passed. As the Times piece reported: