Search results

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

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.

Mounting on roof at the right ground level can greately impact on antenna performances because will affect the radiated angle of energy.

This article describes a simple yet effective multi-band vertical HF antenna design that performs exceptionally well across 80m to 10m bands. The antenna consists of a 13.4m wire mounted on a 12.4m Spiderpole, complemented by four 12m radials and a ground rod. Initially tuned with a manual LC circuit, it was later upgraded with a CG3000 remote auto ATU for convenient band switching. Despite antenna modeling software suggesting limited performance on higher frequencies, the system demonstrated excellent DX capabilities across all bands, outperforming more complex vertical antenna designs.

A dual band 40-80 vertical antenna on an 18m Spiderbeam Fiberglass Spiderpole, with monoband performance

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.

This article documents the author's journey in building, modifying, and testing a DIY short vertical antenna for 40, 30, and 20 meters, with potential 80m capability. Initially inspired by Parks On The Air (POTA), the author explores pedestrian mobile operation and details various experiments to enhance antenna performance. The piece highlights challenges, SWR tuning, portability, and practical results, emphasizing a balance between efficiency and size. Ultimately, it showcases the adaptability of DIY antennas for portable ham radio applications.

Mad your own simple FS meter. It is the simplest thing to make and is good enough to see if the antenna under test is radiating more power than your old ground plane, old mobile vertical or just radiating at all in a particular direction or in all directions.

Vertical Base Replacement Coil. Wolf River Coil build quality antenna coils that are easy to tune and easy to install.

An Inverted-L with its long leg sloping to the ground. It will still work very good, even if the horizontal wire has to be sloped diagonally to the ground, as long as you have enough horizontal space to keep it at about a 45 degree angle or more from the pole.

Integrating a **160-meter vertical wire antenna** with an existing 80-meter Yagi system presents unique challenges for Top Band operation. This project outlines the author's experiences with seasonal antenna removal and reinstallation, a necessary task for agricultural land use. It details specific issues encountered, such as incorrect coil sizing and relay configuration problems, providing practical insights into common pitfalls. The article describes the iterative tuning process, comparing **NEC model** predictions with actual on-air performance. It emphasizes the importance of precise measurements and adjustments to achieve optimal resonance and impedance matching. The author shares lessons learned from troubleshooting, including the impact of ground system integrity and feedline considerations. Concluding with an antenna checkup, the resource addresses long-term maintenance aspects, including galvanic corrosion prevention and general upkeep for reliable operation.

The reason for making this antenna was the desire for a vertical (hence DX-ish) antenna that would cover at least 20m that would fit on my 5m fishing pole. This antenna can work on 20m 17m 15m bands and it is suitable for SOTA operations

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.

This is a FULL SIZE quarter-wavelength vertical made on a 18m Spiderbeam fiberglass telescoping Spiderpole

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.

Learn how to set up a vertical HF antenna with 5 bands and a quarter wavelength. Discover the benefits of using this type of antenna for ham radio operators looking for a lightweight, compact, and cost-effective solution. Get insights from professional versions like the DX COMMANDER and real-world experiences from other operators. Find out about the MV6 commercial version and its excellent results. Explore different construction methods and receive tips for quick assembly and disassembly. Stay informed with the latest articles and archives on military transmissions and Morse code learning techniques.

Build A Shortened 40 Meter Vertical antenna For POTA / SOTA Activations. A project for a portable wire antenna for 40 meters band suitable for POTA or SOTA operations.

This article describes the construction of a three-band vertical antenna for the WARC bands (10, 18, and 24.9 MHz). Unlike a previous design using thin wire requiring a complex matching device, this version uses a telescopic set of pipes, reducing reactances and simplifying the matching device to two coils and two capacitors. The article provides details on the antenna model, the matching device circuit, and tuning methods, including the use of frameless coils and variable capacitors. With proper tuning, the antenna achieves a VSWR not exceeding 1.3 across all bands, demonstrating a practical and efficient design for amateur radio enthusiasts.

The GAWANT Antenna, or Shinagawa Antenna is an half-wave vertical end-fed in a FT817-friendly package

Intrigued by a German OM positive experience with a 20m delta loop, the author replicated the design, noting its favorable 50-ohm impedance compared to their 40m version. Testing against a vertical EFHW, the delta loop excelled within EU but lagged at longer distances. Despite needing more testing, the user leaned towards the EFHW for its overall performance and practicality.

This blog chronicles the development of an 80-meter vertical antenna for amateur radio operation. The author constructs a top-loaded vertical using fiberglass poles, achieving significant performance improvements over their previous end-fed wire antenna. Comparative testing using the Reverse Beacon Network and on-air contacts demonstrates 8-10 dB gain on the east coast. The project evolved to include 40-meter capability through a modified design featuring a four-wire vertical cage, loading coil, and strategic guying system. Despite challenges with signal wobble during windy conditions, the vertical consistently outperforms the end-fed wire, particularly for reaching distant stations during nighttime propagation.

Steve Nichols, G0KYA, presents a practical examination of ground systems for vertical antennas, drawing heavily on the empirical research of Rudy Severns, N6LF. He explains that a robust radial field is crucial for ground-dependent verticals, effectively replacing the antenna's "missing half" and mitigating severe RF absorption in lossy soil. Nichols clarifies that surface radials do not strictly require a quarter-wavelength; instead, deploying a minimum of 16 to 32 shorter wires often yields superior results compared to fewer, longer ones. The presentation also addresses the common SWR paradox: a poor ground might show a perfect 1:1 match, but adding radials, while potentially raising the SWR to around 1.4:1, significantly improves true radiation efficiency. Nichols defines counterpoises as elevated wire networks that substitute for earth connections, offering solutions for limited-space installations, such as the **Folded Counterpoise (FCP)** for 160 meters. This resource provides actionable engineering data for optimizing vertical antenna performance.

Vertical antenna tests at the Sonten-Rancabali tea resort in Ciwidey, West Java. The assembly, led by Mr. Dian Kurniawan and the team, took just 20 minutes. Mrs. Mita performed the transmit check-in test, which was received across various regions in Indonesia, including Sulawesi, East Java, and Bangka Belitung. The team will release a video of the test soon and has thanked colleagues YB3HRY and YB0BAW for their reports.

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.

This article on basic antenna theory explains why is a 5/8 wavelength vertical antenna better than a 1/4 wavelength antenna

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.

Operating from Banana Island, Sierra Leone (AF-037), the 9L2019 DXpedition by F6KOP and a ten-operator team used the callsign 9LY1JM from January 9-21, 2019. This detailed report covers the logistical challenges, including securing visas and licenses with local assistance from Mark 9L1YXJ and Gregory of Dalton’s Guest House. The team deployed monoband quarter-wave verticals on the beach and two Beverage on Ground (BOG) antennas for Europe/Asia and the USA, operating four stations simultaneously. Technical hurdles encountered included high tides submerging antennas, requiring repositioning, and persistent QRM between closely spaced stations, mitigated by doubling filters. CW signal irregularities at 30-32 WPM were resolved by PC and WINTEST restarts. A significant FT8 logging bug was identified and corrected with on-site software. Despite these issues, the team logged over 4,000 QSOs in the first 24 hours, averaging 5,000 QSOs daily, with a peak of over 6,000 in one day. Propagation varied, with excellent 160m conditions on January 12 yielding over 750 QSOs, and a later four-hour opening pushing the 160m total past 1,600. High bands were challenging due to low solar activity, but mid-bands provided intense pileups and rapid continent-wide contacts. The DXpedition concluded with nearly 50,000 QSOs, including a successful school QSO with Collège Doisneau de Sarralbe (57), managed by F1ULQ and F6KFT.

A transmitting antenna 2x15m, about 100 foot doublet antenna fed by a ladder line of about 600 Ohm. Article in Polish and English,

a 20M quarter-wave vertical antenna with a 6m telescopic mast, 1:1 balun, and spiral-wound driven element. Designed for QRP at 14.285 MHz, the antenna’s performance exceeded expectations, delivering low SWR and surprisingly quiet reception. Initial testing yielded successful contacts with European stations and EC1KR, showcasing its effectiveness. Compact and easy to deploy, the antenna promises to be an excellent portable solution for future hilltop operations.

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 article provides a detailed guide on how to build a no holes roof mount for ham radio antennas. The author shares their design that can hold 2 masts and offers tips on installation. The mount is versatile and can handle small 144 Mhz or 432 Mhz beams, as well as small verticals. With adjustable angles and spacing, the mount can be customized to fit different roof types. Additionally, the author suggests affordable options for obtaining Dish antenna mounts. Overall, this DIY project offers a cost-effective solution for ham radio operators looking to mount antennas on their roofs.

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

This study details a reception comparison between vertical and horizontal active loop antennas, specifically two identical _Wellgood active loop antennas_, on various HF bands. The experiment, conducted in a densely populated QRM-prone area, monitored FT8 signals over a 24-hour period using two identical receivers. The methodology involved direct comparison of signal reception across the HF spectrum, aiming to identify performance differences based on antenna orientation. The results indicate that vertical loops demonstrated superior performance on higher bands (10m, 15m, 20m), while horizontal loops excelled on lower bands (30m, 40m, 160m), particularly for receiving long-distance (DX) signals. The horizontal loop's advantage on lower bands is attributed to potentially better low-angle performance and reduced sensitivity to man-made noise, yielding a **2-3 S-unit** improvement on 160m. The study provides practical insights for optimizing antenna placement in challenging urban environments, noting that the horizontal loop consistently showed a **10-15 dB** signal-to-noise ratio improvement on lower bands.

This project documents the construction and enhancement of a 30m Vertical Dipole Array (VDA) antenna inspired by Remco 7QNL article. Initial design utilized an 18m Spiderbeam pole and a 4m boom. Improvements included a lighter boom structure using fishing rods and a revised coaxial arrangement for enhanced mechanical stability.

Experimenting and testing vertical antenna for HF bands on mobile operations.

Being frequently away from home, the author owner of an Elecraft KX3 missed the opportunity to work /M. They devised a portable antenna solution, incorporating a coil and car body, enabling multi-band tuning. Despite its unconventional design, the antenna exhibits promising performance, resembling a vertical dipole.

This project outlines the construction of a simple TEFV (Tilted End-Fed Vertical) antenna suitable for backyard or park installations. The design requires basic materials such as 100 feet of coated stranded copper wire, wood stakes, metal ground rods, a non-conductive fiberglass pole, and essential tools like wire cutters and a soldering iron. The antenna is supported by a 20-33 feet tall pole and includes a 9:1 unun for impedance matching and a resistor for tuning. Step-by-step instructions guide the assembly, from preparing the wire and pole to connecting the unun and resistor, ensuring a functional and durable setup for outdoor use.

This project details the construction of a compact, circularly polarized Quadrifilar Helix Antenna (QHA) designed for 146 MHz operation. The antenna features a 1/2λ1/2λ helical design with a 2.6:1 aspect ratio, providing 4.5 dB gain and a spheroid radiation pattern. It is ground plane independent and compatible with both vertical and horizontal polarizations, making it ideal for terrestrial and space communications. The design includes step-by-step instructions for building the antenna using readily available materials like aluminum rods, PVC pipes, and RG-58 coaxial cable. The antenna's performance has been validated through comparisons with commercial omnidirectional antennas, showing superior results.

Showcasing German engineering, ANjo Antennen develops and manufactures a diverse portfolio of amateur radio and commercial antenna products. Their offerings span a wide frequency range from 1.8 MHz to 3000 MHz, emphasizing electrical and mechanical precision for longevity. The company actively participates in events like FUNK.TAG Kassel, providing opportunities for direct engagement and order pickup. ANjo's product line includes high-performance **Yagi antennas** optimized for Tropo and EME, along with multi-stacked Quad antennas designed for contest operations, featuring wide horizontal and narrow vertical beamwidths. They also produce circularly polarized satellite antennas, some with switchable LHCP/RHCP, leveraging their commercial satellite antenna expertise. Beyond amateur applications, ANjo provides flexible, custom antenna solutions for commercial sectors such as BOS, EMC measurements, and telemetry. Their commitment to quality is evident in the Premium-Line antennas, which utilize **1.4301 (V2A) stainless steel** for mast clamps and connectors, ensuring durability and corrosion resistance. They also offer end-fed HF multiband wire antennas, known for their compact footprint and discreet installation.

The article details the C-Pole antenna project, emphasizing its portability and ease of setup for amateur radio operators. Key features include its compact design as a vertical half-wave dipole that requires no radials, making it functional at various locations. The antenna employs capacitive loading to reduce physical length while maintaining efficiency. It includes practical advice on resonance tuning, impedance matching, and construction materials, along with a calculator for determining dimensions based on desired frequencies. Overall, it presents a user-friendly solution for portable ham radio communication.

This page provides detailed instructions on refining an end-fed vertical dipole antenna for ham radio operators looking to improve their signal reception and transmission. The content offers practical tips and techniques for optimizing the performance of this specific type of antenna. The page is useful for hams who are interested in experimenting with different antenna designs and configurations to enhance their overall radio communication experience.

A 5/8 λ antenna, often thought to be ideal for all frequencies, has unique characteristics that don't universally apply. First introduced for medium-wave radio, it works optimally at 225° antenna length over ideal ground, yielding high efficiency. However, at VHF and higher frequencies, it offers no advantage over other antennas due to real ground conditions and complex matching requirements. DIY calculators provide only rough estimates, useful as a starting point for simulations, not for precise builds.

Learn how to easily improve your handheld VHF performance on the 2-meter band with the Flowerpot antenna. This simple DIY antenna made from coaxial cable requires minimal tools and materials, providing a big range upgrade compared to standard rubber-duck antennas. Discover how to build, tune, and optimize the Flowerpot antenna for excellent performance. Ideal for hams looking for lightweight, portable solutions for handhelds, mobile rigs, home stations, SOTA/POTA activations, and emergency communication.

A vertical antenna project for POTA operations. This shortened antenna is aimed to work from 20 to 40 meter band implementing a loading coil, with an additional wire lenght, determined by on field testing and tuning.

This document provides a detailed guide on constructing and mounting a folded dipol for the 146 MHz frequency in a vertical configuration to be used in Yagi antennas. The step-by-step instructions and diagrams included make it easy for hams to build and set up this type of antenna. Understanding and implementing this design can enhance the performance of radio communication for Amateurs operating in the 2-meter band. Whether you are looking to improve your signal strength or experiment with antenna designs, this resource offers valuable insights and practical information.

Antenna patterns are all about interference. Presentation on wire antennas for HF bands. Dipoles, horizontal and vertical dipoles, effects of ground on radiation patterns, multi-band wires antennas. Knowing what you should expect from the radiation patterns for waves on your wires will help you choose what will work best for your needs. The principles of interference can lend insight into what to expect from a wire antenna.

This page provides information on designing a lightweight Moxon antenna for the upper HF bands and VHF. The Moxon antenna is a compact version of a 2-element Yagi with folded elements, offering good forward gain and a high front-to-back ratio. It is designed for a single band with a feed-point impedance close to 50 ohms. Hams can orient the antenna horizontally or vertically, with polarization following the configuration, affecting radiation patterns. The page allows users to generate radiation pattern plots, VSWR charts, antenna currents diagrams, and Smith charts for their antennas on different ground types, helping them understand antenna performance in the field.

This page allows hams to design a vertical-plane delta-loop antenna for a single amateur HF band in different configurations. By choosing different feed-point positions, operators can observe variations in polarization properties, radiation patterns, and feed-point impedances. Users can generate radiation pattern plots, VSWR charts, antenna current diagrams, and Smith charts for their antennas over various ground types. Through adjusting the antenna's physical dimensions and refreshing the plots, hams can gain insights into the antenna's performance in the field. The page also discusses how elevation radiation patterns may change based on the antenna configuration and feed-point position.

Learn how to build your own QRPGuys DS-1 40-10m short vertical antenna for ham radio operators. This page provides detailed instructions on constructing this antenna, which covers the 40 to 10-meter bands. Whether you're a beginner looking to get started with antenna building or an experienced ham radio operator looking for a new project, this resource is useful for anyone interested in DIY antennas for portable or QRP operations.

This page is a discussion about impedance matching by Off Center Fed dipoles in the Wide L-form. When a vertical or horizontal dipole is bent into a 90 degree L-form, the impedance drops about half.