Search results

This type of antenna is a popular antenna design as the performance is very good across the HF bands and requires little or no tuning. It’s a dipole fed off center with a 4:1 balun at the offset feed point. The antenna shown covers 80, 40, 20 and 10 meters. The formula can also be used to adjust the overall length to cover more or fewer bands and the resulting overall length. 160-10m, 80-10m or 40-10 meters depending on your available space. Other bands will require a tuner.

Construction tips of a basic wire antenna, the half wave dipole. Inverted V dipoles and effects of inverted v on radiation pattern.

A review of the GAP Challenger DX Antenna that is not a traditional 1/4 wave vertical, but is a vertical dipole, this gives it several advantages over a standard 1/4 wave vertical, mainly the reduced number of radials, with excellent performances.

Building A Full-Wave Quad Loop Antenna for 6 Meters. This is an easy antenna to build and the materials cost about $15-20. It exhibits 1.8dB gain over a 1/2-wave dipole. Using an open-wire parallel feedline (commonly called ladder line) with an antenna tuner, it tunes up on the 10m band as a 5/8-wave loop as well

Dipole antennas, vertical half-wave dipole antennas with impedence tranformes that can be used for portable operations. Some well worn antenna configurations are the easiest and loudest lash-ups you can try.

This article describes a multi-band antenna design for amateur radio enthusiasts by G3FEW. The antenna is designed to cover at least five HF bands with low SWR and without the need for an ATU. It is also designed to be easy to construct and adaptable for different locations. The antenna is a full-wave dipole with traps at the quarter-wave points. The traps are used to tune the antenna to different bands. The antenna can be fed with a 4:1 balun. The article includes instructions for building the antenna, as well as information on the theory behind its operation. The author also discusses the results of his tests with the antenna. This multi-band antenna is a well-designed and versatile antenna that can be used by amateur radio enthusiasts on a variety of bands. It is relatively easy to construct and can be adapted for different locations.

The Linked Dipole is a multiband antenna designed for 80/60/40/30/20m bands, optimized for the (tr)uSDX low bands configuration. It incorporates a 1:1 Balun to prevent common mode currents, ensuring balanced operation with coaxial cable. The Balun, wound on an FT140-43 core, achieves 37-40dB attenuation. The design includes a 3D-printable housing for compactness and waterproofing, with labeled link insulators for ease of use. Wire lengths were meticulously adjusted for optimal performance with a 7m pole and 3m rope extension, ensuring the antenna's ends are off the ground for improved behavior. The project includes downloadable printables for DIY construction.

On the field comparison among C-Pole antenna, an EFHW vertical antenna and an Inverter V dipole antenna. Test is done using two identical WSPRLite beacons that transmit with 200mW on the WSPR frequency and analyzing spotted results.

A 3 band dipole antenna for 40-80-160 meter bands, It's made with easily available materials and is designed for inverted V mounting. The antenna is shortened for these bands, but still manages to make contacts in 80m and 160m with stations in Canada and the USA. The construction details are provided, including the dimensions of the antenna elements and the traps. The antenna is easy to build and provides good performance in all three bands. In Italian.

A hexagonal beam is a form of the Yagi antenna which is based on parasitic principles developed early in the last century in Japan for achieving gain in one direction.How HexBeam antennas works. A hexagonal beam operates exactly like Yagi antenna, but instead of a driven element that is straight like a dipole, it is a wire bent into the shape of the letter M.

There are several ways to reduce the length of a dipole and still use it as an effective antenna. Remember it is the electrical length that determines resonance. The physical length can be considerably less than a half wave length on your desired frequency as determined by 468/f MHz.

This antenna just requires about 24m of free space instead of 41m that a normal half wave 80m antenna needs to hang up. The so called loaded dipole uses a coil in every dipole arm to electrically lengthen the mechanical too short dipole arms. Every coil has an inductivity of 120 microHenry.

You can bend the wires in a half-wave dipole so that it takes up less space, with minimal loss of efficiency.It is advisable to get the ends of the antenna as high as possible, especially if children and animals are kept in the area around the antenna, as there are very high tensions on the ends of the antenna during transmission! In Norwegian

Operating as FY/F5UII, Christian F5UII conducted a DXpedition to French Guiana (FY) from January 13 to 30, 2013. The primary operation utilized the FY5KE radio club station in Kourou, with activity focused on voice modes during specific weekday hours. The resource details the operator's intent to transmit before 12:00z and after 22:00z, or as availability permitted, from the mainland. A significant aspect of this operation involved a dedicated weekend activation of the Salut Islands, specifically **IOTA SA-020**, from January 19-20, 2013. This segment of the DXpedition was conducted from Royal Island (Ile Royale), part of a group including Devil's Island (Ile du Diable) and St. Joseph Island (Ile Saint Joseph), located 14 km offshore from Kourou. The station setup for the IOTA activation included 100 Watts of power, a GPA-030 vertical antenna for 10m, 15m, and 20m, and dipole antennas for 17m and 40m, with antenna deployment contingent on site conditions and propagation. The operator anticipated strong interest for the SA-020 entity.

This page delves into the Inverted V antenna, a source of myths among ham radio operators. The author explores the behavior of this antenna type with a focus on a 20m half-wave dipole positioned 10m above the ground. From Pythagoras to high school math, the article simplifies the calculation of dimensions and angles for setting up an Inverted V antenna. It includes a spreadsheet for calculating hypotenuse length and angles, crucial for antenna setup. Additionally, it provides insight into the radiation pattern of a 'flat' half-wave dipole at 10m height. Useful for hams planning to optimize their antenna setup. In Norwegian.

This is a vertically polarized Broadside and Collinear Array each Loop is a vertically polarized Broadside Array both the right and the left side of the Loop is a bent 1/2 wave dipole working 180 degrees out of phase with the other one and that gives you 4.15dbi of gain

Building an 80-160 meter antenna in a small garden (9m x 14m) involves creative solutions due to space constraints. This project outlines the construction of a trapped 80-160 meter vertical dipole, utilizing a crank-up tower and an 11-meter fiberglass pole. The design prioritizes minimal visibility, ease of construction, and cost-effectiveness, achieving effective operation despite limited space.

This antenna looks like an inverted L antenna, yet it is not, it could also be viewed as a 160m off-center fed dipole antenna, it looks more like an end-fed 1/4 wave 160 meter antenna.

Here is a formula and calculator for creating a loaded (shortened) quarter wave vertical or balanced dipole. The calculation refers to either a loaded 1/4 wave or a loaded dipole

Antenna most often used by Hams around the world. Inexpensive, effective and easy to build, what more could anyone ask for in a home made antenna.

Listen to online WebSDR located in Andorra Europe. Four receivers on 60m, 20m, 40m, and 80m, connected to a dipole antenna direction East/West

This PDF guide provides detailed instructions and diagrams for constructing a fan dipole antenna, a popular choice among hams for multiband operations. The guide covers the design, materials needed, and installation process, offering step-by-step guidance to help hams set up an effective antenna system for their radio operations.

The Bazooka antenna, a coaxial dipole, functions as an omnidirectional antenna with vertical or horizontal polarization. Patented in 1939 and refined in 2006, it features a quarter-wavelength coaxial cable with separated conductors. The outer conductor connects to a sleeve, while the inner conductor extends vertically. Initially complex, it has been simplified for versatile use, including military applications. Adding elements can modify its behavior for NVIS or Yagi-Uda configurations. Experiments in 2007 at the Campus de Pesquisas Geofísicas in Paula Freitas-PR demonstrated consistent VHF and UHF performance, showing reliable return loss measurements despite variable weather.

Extended Double Zepp measurements for all ham bands, and online calculator. 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

This article describes the construction of a 9,50 m long dipole for the 30 m band (10.1 MHz to 10.15 MHz). It was designed to be mounted ca. 6 m above ground inside an attic. The calculations were performed by OE1MEW

The Tri-pole antenna, a clever modification of a standard dipole, allows for dual-band operation by integrating a third element. This design effectively shortens the overall dipole length by 10 to 20 percent, simplifying antenna rotation and offering a compact footprint. KK4OBI's article delves into the operational principles, using a 6 and 10-meter Tri-pole as a primary example, and provides comprehensive instructions for constructing any Tri-pole antenna within the 6 to 15-meter range. Key to the Tri-pole's performance is its off-center feed, necessitating a common mode choke at the feed point for optimal tuning and reduced noise. The author outlines a methodical approach to determining element dimensions, starting with a vertical element frequency calculated as 0.47 times the sum of the desired upper and lower band frequencies. This calculation, along with K-values derived from trend lines, guides the initial lengths for the horizontal arms, demonstrating how a 10m-6m Tri-pole can achieve a total horizontal length 78% shorter than a conventional 10-meter dipole. Tuning and balancing are critical, with the article detailing adjustments to arm lengths and the vertical element to achieve balanced SWR values, as validated through 4NEC2 simulations. Radiation patterns are analyzed at various elevations, showing gains around 5.7 dBi and favorable take-off angles for DX contacts. Construction details specify aluminum tubing dimensions, U-bolts, and an SO-239 connector, emphasizing the importance of a ferrite-based choke for wideband operation.

This article explores the evolution of antenna choices for DXpeditions, focusing on the shift from mono-band VDAs to a multi-band solution. It details the design and construction of a lightweight, versatile 20-17-15m VDA, utilizing readily available materials like fishing rods and IKEA breadboards. The author discusses challenges, adjustments, and offers guidance for replication.

The video showcases the setup of a 300 MHz oscillator, a 100W radiofrequency amplifier, and a dipole antenna for transmitting radio waves, leading to the fluorescence of a nearby light bulb. It demonstrates the presence of standing waves on the dipole antenna and how intensity varies along its length. Additionally, the usage of a copper pipe as a receiving antenna is explored, showing changes in intensity depending on alignment and proximity to the transmitter. Finally, a B field antenna sensitive to magnetic fields is introduced, revealing brightness variations in different orientations. The video offers insightful observations on radio wave transmission and reception phenomena.

The CobWebb antenna project is a compact, multiband HF solution ideal for amateur radio operators. Covering 14-28 MHz, it features a square dipole array with near-omnidirectional coverage and unity gain. This guide details a DIY approach, using a 1:4 current balun for impedance matching. Construction involves aluminum and fiberglass tubing, with optimized element tuning for SWR performance. Weather resistance improvements and resonance shift considerations are also discussed. Build your own CobWebb antenna for an efficient, space-saving HF experience.

This page presents an online calculator tool for determining the dimensions of various HF wire antennas operating between 1.8-30 MHz. Users input their desired resonant frequency to obtain precise measurements for four popular antenna types: standard flat-top dipole, inverted Vee, quad loop, and equilateral delta loop. The calculator provides comprehensive measurements including leg lengths, minimum heights, horizontal spreads, and feedpoint distances. Accompanying the calculator are detailed technical explanations, construction notes, and installation guidelines for each antenna type, making it a practical resource for amateur radio operators building their own antennas.

Online antenna parts store, providing many accessories for amateur radio antenna homebrewing. Boom joiners, aluminium parts, elements clamps, filters, ferrites, fasteners, plasti caps, dipole elements. Based in UL

Make your own dipole for 40 and 80 meters band, assembling standard product parts like 40 meter traps, the 1:1 balun and insulators

Originally designed by John Kraus, W8JK in about 1940, this antenna has some interesting properties. The W8JK antenna is 2 (Two) centre-fed double-dipole fed by a pair of anti-phase signals. Small size, simple antenna, offer nice performance but need a tuner. Tested in this project from 30m to 6m bands

This article discusses suitable first HF antenna options for amateur radio operators with limited space. It recommends an Off-Center Fed (OCF) Dipole and a Vertical Dipole, detailing the installation processes, considerations for stealth and ease of setup, and the characteristics that make them ideal for newcomers. Safety warnings and maintenance tips are provided to ensure effective and secure operation.

The title may seem a strange question. Still, it is often said that the part where the current is largest, radiates most. And from that a rule of thumb follows, saying that if you don't have enough space to hang a complete half-wave wire dipole then try to make the central part hang as freely as possible.

Building an End-Fed Half-Wave (EFHW) antenna from a kit, as detailed by Frank Bontenbal, PA2DKW, with process photos by Bob Inderbitzen, NQ1R, offers a practical approach for hams. This specific kit, a collaboration between ARRL and HF Kits, targets 10, 15, 20, and 40 meters, making it a versatile option for HF operations. Unlike a center-fed dipole, the EFHW is a half-wavelength antenna fed at one end, which simplifies deployment, particularly for portable use. The construction guide meticulously outlines the assembly of the 49:1 impedance matching network, crucial for transforming the antenna's high impedance (around 2,500 Ohms) to a transceiver-friendly 50 Ohms. Steps include preparing the enclosure by drilling holes for the coaxial connector and antenna connections, followed by the precise winding of enameled copper wire onto a toroid to create the transformer. The guide emphasizes careful insulation removal and soldering for reliable connections. Final assembly involves integrating a 100 pF capacitor for higher band compensation, soldering the transformer's primary and secondary sides, and conducting SWR tests with a 2K7 resistor or a half-wavelength wire. The document also provides examples of wire lengths for different bands, such as 16 feet for 10 meters or 66 feet for 40 meters, demonstrating the transformer's adaptability for various half-wavelength configurations.

Constructed in May 2008, this innovative 4m tall electrically full-size halfwave vertical dipole, tunable to multiple bands, offers HF coverage despite its space-saving design. Inspired by cost-effective DIY alternatives, the antenna design departs from conventional center-fed approaches, utilizing asymmetrical dimensions. Despite resonance challenges, the antenna's performance remains viable, boasting broad bandwidth and adaptability, as demonstrated through SWR measurements and EZNEC predictions.

Build a low-cost 20m shower rod dipole antenna

This document details the construction of a multi-band end-fed antenna, suitable for situations with limited space for larger antennas. The design utilizes a 1:49 to 1:60 impedance transformer to match a half-wave wire antenna fed at one end. Compared to a traditional dipole, this antenna resembles a highly unbalanced Windom antenna with one very long leg and a virtual short leg. The design eliminates the need for radials but relies on the coax cable shield for grounding. The document recommends using at least 10 meters of coax and installing a common mode filter at the entry point to the shack for improved performance.

In this article the author describes his personal experience on some antennas for 50 MHz he tested on the field, the six meter Dipole, Vertical, Moxon, a 3 element Yagi and an Omniangle antenna.

A Trapped dipole inverted V antenna for lower HF Bands. Construction details are for temporary installation. Permanent installations will require additional ruggedising and waterproofing however the basic electronics concepts remain the same. This project includes SWR plots for the three bands and pictures details of the homemade traps.

This article presents the C-Pole antenna project, a compact, ground-independent vertical antenna designed for amateur radio operators. It features a folded half-wave dipole configuration that eliminates the need for radials, making it suitable for various locations, especially in deed-restricted areas. The C-Pole offers efficient performance with a 2:1 SWR bandwidth of approximately 3%, and it can be easily constructed using common materials. Additionally, the article discusses practical aspects such as feed-point impedance transformation and balun design to optimize functionality and minimize losses.

Discussion about laterally bent-end dipoles. Bent by percentage of length and fine-tuned by angling the bent ends.

Discussion about the Standard Horizontal, Center-fed dipole and effects of elevation of the antenna on antenna radiation pattern.

The HB9CV antenna calculator aids amateur radio enthusiasts in designing antennas for VHF and UHF bands. By inputting the working frequency, users can obtain crucial dimensions like dipole lengths and distances. The tool, based on the HFSS antenna model, provides data on impedance, VSWR, and gain, optimizing front/back radiation ratios. It includes tips for fine-tuning using a Г-matching balun and compensating capacitor, ensuring effective performance and minimal VSWR for enhanced radio communications and direction finding.

A rotatable 40-meter dipole antenna designed and constructed to fit within backyard constraints. The project utilized two fishing poles attached to a fiberglass center pole, resulting in an easy-to-build, lightweight, and cost-effective antenna. Essential materials included fishing rods, a center support pole, mast support, and basic tools. Linear loading was implemented to achieve the necessary length for optimal performance. The antenna, which proved effective during the contest, is ideal for field days and additional contest bands. Assembly and installation were straightforward, showcasing the antenna's practicality and efficiency.

This article describes the construction of a simple dual-band VHF/UHF end-fed vertical dipole antenna designed for local repeater access using an Icom IC-705 radio. Built from a single piece of RG58U coaxial cable, the antenna consists of a 460mm exposed inner conductor, 450mm of intact coax, and a 9-turn choke balun wound on a 27mm former. Mounted on a 10m Spiderpole, the antenna achieves excellent SWR readings (<1.2:1 on 2m, <1.5:1 on 70cm) and provides effective coverage of local repeaters with unexpected reach into distant locations.

This page offers an online antenna designer to calculate the dimensions for a collinear dipole antenna at a specified frequency. The collinear dipole antenna is constructed with multiple 1/2 wavelength sections separated by a 1/4 wave phasing stub in the form of a coil. It requires a ground-plane to operate and can be used for both receiving and transmitting purposes. The antenna can be made from common copper wire, with thicker wire providing a wider bandwidth. The calculations are based on radio waves traveling at the speed of light. Ideal for ham radio operators looking to build their own antenna for improved reception and transmission.

Online antenna calculator for a basic 3 elements yagi uda directional antenna. The described antenna design offers a front-to-back ratio of at least 20 dB, a gain exceeding 7.3 dBi, and a bandwidth (SWR < 2) of approximately 7% around the center frequency. It has an input impedance of 50 ohms when using a straight split dipole, which can be substituted with a folded dipole of the same length, increasing the impedance to 200 ohms. A matching balun is required for coaxial feeder connection, and the boom should be made of a dielectric material, like wood.

The article describes the construction of a Lindenblad antenna, which is well-suited for receiving signals from low-orbiting weather satellites. The key points are: The Lindenblad antenna has an omnidirectional horizontal radiation pattern and is optimized for low to medium elevation angles, making it ideal for tracking passing satellites near the horizon. It is designed to receive circular polarization, which is common for weather satellite signals. The antenna is constructed using 4 folded dipole elements arranged on a cross-shaped frame. The necessary materials include a plastic junction box, PVC tubing, and aluminum rods to form the dipole elements. The article provides detailed instructions for preparing the components, assembling the dipoles, and connecting the feed lines to create the complete antenna. The completed antenna can be mounted on a vertical support, with the dipole elements angled at 30 degrees from horizontal, to optimize reception of the passing satellites. The author notes that the design was originally published in a now-defunct magazine, Meteo Satellite Inf", in 1993