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A distributed capacity coaxial dipole antenna. The antenna is very broadbanded with a very flat swr on all band when setup of the antenna is done at the proper lenght and height.

The 160-meter amateur radio band, spanning 1.8 to 2 MHz, was historically the lowest frequency amateur allocation until the introduction of the 630-meter and 2200-meter bands. ITU Region 1 allocates 1.81–2 MHz, while other regions use 1.8–2 MHz. This band, often called "Top Band" or "Gentleman's Band," was established by the International Radiotelegraph Conference in Washington, D.C., on October 4, 1927, with an initial allocation of 1.715–2 MHz. Effective operation on 160 meters presents significant challenges due to the large antenna sizes required; a quarter-wavelength monopole is over 130 feet, and horizontal dipoles need similar heights. Propagation is typically local during the day, but long-distance contacts are common at night, especially around sunrise and sunset, and during solar minimums. The band experienced a resurgence after the LORAN-A system was phased out in North America in December 1980, leading to the removal of power restrictions.

This web article details the construction of a 4-meter band coaxial dipole antenna, designed for operation between **70.000 MHz and 70.500 MHz**. The resource provides a bill of materials and step-by-step assembly instructions for a half-wave dipole constructed from _RG-58_ coaxial cable. The design specifies a direct 50 ohm feedpoint impedance, eliminating the need for an external matching network. Construction photographs illustrate the stripping and soldering processes for the coaxial cable elements, ensuring proper electrical connection and physical integrity. The article includes specific dimensions for the radiating elements, derived from calculations for the 70 MHz band. The project outlines the physical dimensions required for resonance at 70 MHz, with the outer braid forming one half and the inner conductor forming the other. The feedline connection is directly to the coaxial dipole's center, maintaining a 50 ohm characteristic impedance. While the article does not present SWR plots or VNA sweeps, it focuses on the mechanical construction and dimensional accuracy for achieving a functional 4-meter dipole. The design is intended for fixed station use, with no specific mention of polarization or height above ground, but implies a standard horizontal orientation for dipole operation. DXZone Focus: Web Article | 4m Coaxial Dipole | Construction Guide | 50 ohm Feed

An experimental prototype of an asymmetrical hatted vertical dipole antenna that can work on HF bands 20 to 10 meters band. The AHVD Vertical dipole is an upside-down T design

The standard J-Pole antenna is a end fed 1/2 wavelength antenna, in this article is explained also how to build an expanded Super J Pole that provides about 4.5 dbd gain. These antennas can be built from EMT electric conduit pipe

Living in a no antenna deed restricted community sounds bad for a HAM, but it means you just need to be more creative. I have found this will not stop your DXCC activities and many of my local HAM club members will agree

The resource, "Conventional Use of Transmission Line," meticulously details the operational principles of transmission lines, emphasizing the Transverse Electromagnetic (TEM) mode of energy transfer. It clarifies that for a line to function purely as a transmission line, all currents must be confined internally, with external fields ideally zero. The discussion differentiates between balanced and unbalanced lines, asserting that while both require equal and opposite currents within the conductors, the key distinction lies in the voltage relationship of each conductor to the surrounding environment. It highlights that a good antenna pattern does not inherently confirm proper feeder balance, and that common-mode currents can lead to RF in the shack and increased noise levels, even without pattern distortion. The article further explains that a transmission line can become a radiating conductor if energy is applied in a non-TEM mode, leading to common-mode issues. It cites classic texts like Jordan and Balmain's "_Electromagnetic Waves and Radiating Systems_" and Kraus's "_Antennas_" to support its definitions of TEM mode operation. The content also explores non-transmission line applications of parallel or concentric conductors, such as _coaxial dipoles_ and _folded dipoles_, which intentionally operate in non-TEM modes for antenna functionality. The author, _W8JI_, stresses that simply measuring equal currents is insufficient to confirm a balanced feeder; phase and voltage balance to ground are equally critical.

The video delves into the fascinating science behind antennas, which are crucial for receiving and transmitting electromagnetic waves. It explains how antennas convert electric signals into electromagnetic waves for transmission, and how they operate through the oscillation of positive and negative charges in dipole arrangements. Practical antenna implementations, such as dipole antennas for TV reception and Yagi-Uda antennas with reflectors and directors, are also discussed alongside modern dish TV antennas with parabolic reflectors for signal processing. It's a comprehensive overview of how antennas work and their significance in communication technology.

The ZS1J/B beacon operates on 28.2025 MHz with 5 Watts output to a half-wave, end-fed vertical antenna, initially installed in 1977 as ZS5VHF near Durban. The 10-meter transmitter is a modified 23-channel CB radio, and the identification keyer uses a diode matrix unit with TTL ICs from the same era. After relocation to Plettenberg Bay in 1993, the beacon has been in continuous service, with additional QRP transmitters later installed for other bands. In 1994, a single-transistor, 80-meter, 0.5-watt QRP transmitter with a half-wave dipole was added on 3586 kHz, followed by a 160-meter, 0.5-watt unit on 1817 kHz. A 30-meter, 0.5-watt transmitter was installed in 1996, operating on 10.124 MHz. In 2002, a 40-meter QRRP beacon on 7029 kHz, with an output of 100 microwatts, achieved DX reports up to 1100 km from ZS6UT in Pretoria. Best DX reports for the 80m and 160m beacons came from 9J2BO.

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.

Presents various amateur radio topics through blog posts, detailing operational experiences and technical insights from the perspective of SV2YC. The content frequently discusses antenna projects, such as a **portable 20m/40m dipole** designed for rapid deployment, and explores the performance characteristics of different wire configurations in varied field conditions. Observations on propagation and band activity across the HF spectrum are also regularly documented, providing practical context for fellow operators. Specific entries often include detailed accounts of **DX contacts** and participation in minor contests, outlining station setup, power levels, and antenna choices. The blog also covers modifications to commercial transceivers and homebrew accessory construction, offering practical advice on improving station efficiency and functionality. Further posts delve into software applications for logging and digital modes, sharing configurations and operational tips for maximizing their utility in daily amateur radio activities.

A 60-foot available space, for example, might necessitate a shortened multiband dipole array to cover 80, 40, and 15 meters effectively. This resource details the construction of such an antenna, combining full-size and coil-loaded dipoles on a single feedline. It addresses the common challenge of fitting multiple HF bands into restricted physical footprints, providing practical guidance for hams with smaller backyards or portable operations. The core of the offering is an interactive calculator that determines required loading coil inductance and dipole lengths for various amateur bands from 160m to 10m. Users input their available space, and the tool provides dimensions, coil turns, and an efficiency rating (Good or Fair) based on the antenna's electrical length relative to a quarter-wavelength. It also suggests suitable _PVC_ pipe diameters for coil forms. The article further illustrates a center feed-point assembly using an 18-inch section of 2-inch _PVC_ pipe, detailing eye-bolt spacing and coaxial connector installation. It emphasizes the importance of adequate spacing between parallel dipoles and offers customization options for the feed-point, including the addition of a _Balun_ for improved feedline isolation.

Discovering a solution for limited space, the inverted L HF antenna emerges as a stellar performer. Half the size of a dipole, it ensures optimal installation in restricted areas, maintaining superb transmission (TX) and reception (RX) characteristics. Spectrum Communications' multi-band version, featuring traps, proves even more space-friendly without compromising performance. A fiberglass pole offers sturdy support, while proper grounding, an RF choke, and occasional tuning contribute to a high-performing and reliable antenna system.

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.

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.

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

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.

Dipole for 40m band. It is a simple linear loaded dipole feeded with 450-Ohm openwire feedline. Designed it for resonance at 7.050 MHz, can be tuned on 30m and 80m bands with an external antenna tuner. Build with simple electrical copper wire (2.5 mmq/13 awg) and two fishing poles with size of about 7 m/23 ft.

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.

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 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.

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.

In this post, we describe how to make a pigtail cable to connect the Kenwood TH-F6A triband HT to a 12Vdc power source via an Anderson PowerPole connector.

This article details a ham radio operator’s experience setting up HF antennas in an antenna-restricted community. Initially using an AEA Isoloop magnetic loop for QRP PSK, the author later built an attic antenna system, including dipoles for multiple HF bands and a slinky dipole for 40 meters. The setup allowed for operation on six bands with acceptable VSWR. Despite space constraints and some compromises, performance was effective. The article highlights practical strategies, emphasizing experimentation and antenna modeling for optimizing performance in limited-space environments. A valuable guide for ham radio operators facing similar restrictions.

The Slim Jim Antenna Calculator is an online tool that helps hams design a Slim Jim antenna for any desired frequency. This extended version of the J-Pole antenna design does not require a ground plane and is perfect for mounting inside PVC piping. The calculator determines the dimensions of the antenna elements based on the input frequency. Suitable for both receiving and transmitting purposes, this antenna can be easily constructed using common household wiring. The tool provides metric and imperial measurements, along with visual representations of the antenna design for easy reference.

From March 2 to March 11, 2018, a Norwegian team operated as Z2LA from Zimbabwe, focusing on 160m through 10m bands using SSB and CW modes. The operation, described as "holiday style," aimed to provide contacts for DXers worldwide seeking a rare DXCC entity. Key equipment included a SUNSDR PRO II, an Elecraft KX3, and an Icom 706 MK2G as a spare radio, supported by two Juma 1000 amplifiers for robust signal output across the bands. Antenna systems were tailored for multi-band operation, featuring an Inv L for 160m and 80m, sloping dipoles for 30m/40m, and a _Hexbeam_ from SP7IDX Technology covering 20m to 10m. For improved reception, the team deployed a SAL 30, two reversible BEV antennas from remoteqth.com, and a BOG from K1FZ, enhancing their ability to hear weak signals. QSL information directs operators to Clublog for log search and M0OXO Charles for OQRS, explicitly requesting no bureau cards. The team comprised LA7THA Rune, LA7WCA Arne, and LA9VPA Thor, successfully making numerous contacts and contributing to the DX community's pursuit of _Zimbabwe_ as a DXCC entity.

Learn how to design a Hentenna antenna, a portable asymmetrical double-loop antenna ideal for amateur HF or VHF bands. This page provides details on constructing and optimizing the antenna for maximum performance in DX communications. Discover how altering the antenna's vertical feed section can adjust the VSWR resonant frequency and how changing the support pole's position can alter the beam direction. Originally developed by Japanese 6-meter operators, the 'Hentenna' offers a unique design that allows for horizontal polarization when vertically oriented. Explore radiation patterns, VSWR charts, and antenna currents diagrams to optimize your antenna's performance for long-distance contacts.

This document outlines the construction of a homebrew Buddipole antenna variant, designed for portable use and emergency services. The antenna utilizes telescoping whips and loading coils, enhancing its versatility across various HF bands. Key components include fiberglass rods, brass fittings, and Anderson Power Pole connectors, ensuring robust electrical connections. The design emphasizes non-inductive materials to minimize interference, while practical assembly techniques, such as epoxy and heat shrink tubing, are employed for durability. This variant aims to improve upon traditional Buddipole designs, offering greater strength and functionality.

The Portable EFHW antenna for the 40, 20, 15, and 10-meter bands utilizes a broadband transformer with a 1:49 ratio, designed on a PCB by either Jan or DL2MAN. The design incorporates an **FT114 core**, offering an alternative to the FT82 core. The antenna requires precisely 20.5 meters of DX Wire Ultralight for optimal performance. Additional components include DX Wires "Dyneema" 1mm rope and 1mm bricklayers string for structural support. The SWR plot indicates performance at two elevation heights: 5.5 meters (blue line) and 4 meters (yellow line), demonstrating optimization for low-elevation portable use without poles. The antenna's components, including spool and rope tensioners, are available for 3D printing, with spool dimensions scaled to 130% for a length of approximately 110mm. The design emphasizes simplicity and portability, suitable for field deployment.

The behavior of a straight dipole and its L-form is examined in terms of impedance and SWR. By adjusting the feed point or bending angle, impedance variation is observed. Impedance shifts symmetrically as the feed point deviates, leading to recommendations for optimal ratios. Model simulations aid in understanding and fine-tuning, crucial for achieving a 50 Ohm match. Practical tuning guidelines ensure efficient antenna performance.

Demonstrates the construction and portable deployment of a 40-meter horizontal loop antenna, often referred to as a "Sky Loop" or "DX-Buster." The design adapts a full-wavelength horizontal loop for field use, eliminating the need for traditional insulators by employing four 5-meter heavy-duty _squid poles_ and metal post bases for support. This setup facilitates rapid assembly, crucial for portable operations, with the antenna wire length specified at approximately 43-45 meters for optimal 40-meter band performance. The resource details the specific construction methodology, including winding the antenna wire around rubber caps on the squid poles and securing it with electrical tape. It provides a parts list and assembly techniques, focusing on minimizing components for ease of transport and quick setup. The article, originally published in the February 2013 edition of the Central Coast ARC "Smoke Signals" magazine, reflects practical experience. This documentation offers a field-deployable 40-meter loop antenna solution, utilizing readily available components like fiberglass squid poles. It presents a practical approach for operators seeking a robust, portable antenna for the 40-meter band, emphasizing simplicity and efficiency in its design and deployment.

A 13-foot total radiating element length is achieved by combining a Buddipole Long Telescopic Whip with 4 feet of modified tripod tubes, forming a low-profile, multiband antenna for **POTA** operations. The resource details the transformation of an Amazon Basics Aluminum Light Photography Tripod Stand, focusing on electrically isolating the top two radiating sections from the bottom support. John, VA3KOT, outlines component sourcing, including the 9-foot 4-inch fully extended whip, and emphasizes using adhesive copper tape for reliable electrical contact and conductive grease to prevent oxidation at tube connections. The construction process, while not requiring specialized tools, highlights careful assembly to ensure proper electrical conductivity and mechanical stability. The author's experience with this setup suggests its effectiveness for portable activations, offering a discreet profile compared to larger antenna systems. The design prioritizes ease of deployment and transport, making it a practical solution for operators seeking a compact yet versatile antenna for field use.

Fully functional weathervane conceals an efficient 2- meter base-station antenna. Your Neighbors and HOA won’t know it’s there and they will love the rooster-vane. The Rooster-Tenna is a covert 2-meter ham radio antenna disguised as a functional weathervane, ensuring seamless integration into residential environments. This improved version features a wide-spaced parallel-fed folded dipole in a compact skeleton slot design. Constructed from aluminum tubing and acrylic supports, it offers omnidirectional, vertically polarized performance suitable for repeater and satellite use. Easy to mount and tune, it achieves a low SWR across the 2m band. With 3D-printable parts available, the Rooster-Tenna blends practicality with stealth, making it an ideal solution for HOA-restricted areas

The **5-Port 12 Volt DC Power Strip Kit (Rev 4)** offers a practical solution for managing shack power distribution, providing one input and five fused outputs. All connections utilize the ubiquitous Anderson PowerPole connectors, a standard for many amateur radio operators, ensuring a clean, organized, and safe way to power multiple 12 VDC transceivers and accessories from a single source. This design mitigates the common issue of tangled wires and overloaded connections in a typical ham shack. Rated for a maximum current of 20 Amps at 12 VDC, the strip incorporates an integrated LED to indicate when external power is applied. Each output is individually fused, a critical safety feature that protects connected equipment from overcurrent conditions without affecting other devices on the strip. This level of protection is essential for preserving sensitive radio gear during operation. Assembly requires basic soldering skills and hand tools, with a high-power soldering iron and wide chisel tip specifically recommended for best results. The kit's compact dimensions of 4.13" x 1.78" allow for flexible mounting via screw holes, making it suitable for various shack configurations and portable operations.

This web page offers an online antenna designer tool for hams to calculate the dimensions needed to construct a J Pole antenna for any desired frequency. The J Pole antenna is a simplified version of the Slim Jim antenna, radiating and receiving signals in an omni-directional pattern. It does not require a ground plane, making it suitable for indoor mounting. With the ability to be made from common household wiring, this antenna performs well for both receiving and transmitting purposes. The calculator is based on radio waves traveling at the speed of light and provides metrics in both imperial and metric units.

The 4m Slim Jim antenna project provides a construction guide for a low-cost, high-performance aerial designed specifically for the 70 MHz FM band. This design achieves a 1:1 SWR across the 4m FM band with straightforward adjustment of the feed point, utilizing RG-58 coax. Its low angle of radiation contributes to effective signal propagation. Construction involves using plastic knitting needles as spreaders and a telescopic fishing pole for support, with components secured using two-part epoxy. Annealed bare single-core copper wire forms the radiating element. The setup process includes raising the antenna at least 3 meters above ground for tuning, adjusting the RG-58 feed point for optimal SWR, and then soldering connections. Waterproofing is achieved with yacht varnish. The design emphasizes low wind resistance for durability, making it suitable for exposed outdoor installations. A PDF construction diagram is available to supplement the written instructions.

Presents an online retail platform for amateur radio operators, showcasing a diverse inventory of equipment and accessories. The site lists popular transceivers such as the _Icom IC-7300_ and _Icom IC-7610_, alongside various antenna solutions including base, HT, mobile, and end-fed designs. Operators can find coaxial cable, including bulk options and products from "The Wire Man," essential for shack setup. The platform also stocks crimping and stripping tools, adapters, and power supplies, crucial for station maintenance and construction. Test equipment like _RigExpert Analyzers_ and accessories such as Daiwa meters and _West Mountain Radio_ Power Poles are available. Additionally, the site offers software from _Ham Radio Deluxe_ and _RT Systems_, catering to logging and radio programming needs. Shipping policies include free shipping on C.Crane Radios and most orders over $100.00 within the lower 48 states, providing clear purchasing incentives.