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Schematic diagram and description of a magnetic loop antenna that works from 10 to 20 meters band, made from junk

Refurbishing a Cushcraft A3S, by George Szymanski, DU1GM

Magnetic Loop Antenna for 20/15m with Remote Tuning by George Szymanski

The fan dipole antenna as an alternative to the paralled dipole antenna, to achieve a larger bandwidth and a better tuning by decreasing elenment influences.A project based on the W6HDG original concept.

G4ILO compares popular antennas for 2 metre band handhelds so as to see how much you lose using a small inconspicuous antenna or how much you gain by using a long antenna.

With the view to establish a quick and easy multi-band antenna deployment for portable and camping operations a simple long wire antenna with an earth or earth plus counterpoise arrangement with a 9:1 voltage unun including a tuner or simply with a tuner is one possible solution. With the 9:1 voltage unun and wire lengths suggested in the below tables the antenna should present non extreme impedances for all HF amateur band frequencies. This page is far from complete and represents the ongoing investigation into this type of antenna. Experiments to date seem to have raised more questions than obvious answers.

Design of a 40 meter Vertical antenna

A comparative article on performance differences between Slim Jim antennas versus J-Pole antennas

A general article on CMC, common mode choke include a description and tipical usage.

Amateur Radio - Antenna Zoning Book by Fred Hopengarten Telecommunications Lawyer

Find out how much to adjust the length of a quarter wave whip or a half wave dipole rather than the outright cut-and-try method.

DK7ZB's fan dipole designs address the challenge of operating multiple HF bands with a single feedline, providing practical construction details for **multiband wire antennas**. The resource outlines specific lengths for half-dipoles across various band combinations, including 10-15-20m for classic bands and 12-17-30m for WARC bands. It emphasizes the importance of proper spacing between resonant elements to avoid impedance interaction and high SWR, a common issue when frequencies are too close. The article details the use of **current baluns** built with FT240-43 or FT140-43 cores, specifying turns and cable types for 1KW and 400-Watt power levels. It includes a correction table for adjusting dipole lengths based on frequency shifts, aiding in fine-tuning resonance. The 20+40m dipole is noted for its ability to operate on 15m with an ATU, demonstrating versatility.

Presents construction details for Moxon antennas, specifically focusing on 10-meter and 17-meter band configurations. It covers practical aspects of building these directional wire arrays, including element spacing, feedpoint considerations, and material choices for optimal performance. The resource emphasizes homebrewing techniques suitable for amateur radio operators. Discusses the advantages of the Moxon rectangle design, such as its compact footprint compared to a full-size Yagi and its favorable front-to-back ratio. It provides insights into achieving proper impedance matching and structural integrity for portable or fixed installations. The content includes photographic examples of constructed antennas. Explains the iterative process of tuning and optimizing Moxon antennas for specific frequency segments within the 10m and 17m bands. It offers guidance on minimizing SWR and maximizing gain, drawing from real-world building experiences to assist constructors in replicating successful designs.

Antennas for Broadcasters, PSI manufactures a complete range of slot antennas for UHF television broadcasting

An antenna for shortwave radio broadcasting consisting of rows and columns of dipoles, is a high gain directional antenna, designed for medium and long range communications.

Quad antenna homebrewing, mechanical considerations by IZ7ATH

Testing performances of indoor antenna. A comparison of a magnetic loop antenna vs a classic wire dipole done using wsprlite on 30 meters band.

Construct a compact, 20 meter rotatable dipole antenna of durable weather worthy components supported at a single point obviating the need for multiple supports and multiple support ropes crossing the yard.

The AB2RA bowtie 80 meter antenna includes also a 40 meter dipole

Some Notes on the Slim Jim Antenna by Dave Coomber M0UXB

Small antenna, what causes loss and how to increase radiation resistance in small antennas., A description of loss and radiation resistance.

Cushcraft A3S HF antenna 1:1 balun repair.

Electrically shortened dipole antennas, article by Mark Connelly, WA1ION

A homemade 70cm handitenna made with a PVC pipe

The vertical Double-Zepp 2x7 m is a very simple, effective 8-Band-antenna. The end of the Dipol must be 5-10 m above the ground

Constructing a Compact Low Cost Sprinkler Valve Antenna Launcher

All about dipole antenna construction

Theory of the ferrite rod antenna

A magnetic loop antenna for the VHF band, featuring a high gain that can be compared to a quarter wave vertical antenna

The resource details the construction of a multiband trap-style Inverted-V antenna designed for operation on 3.5 MHz, 7 MHz, 14 MHz, 21 MHz, and 28 MHz. It presents specific winding data for the traps, including the number of turns, wire gauge, and coil former dimensions, crucial for achieving resonance on the target bands. The document provides a parts list and a diagram illustrating the antenna's physical layout and trap placement. It outlines the process for building the traps using PVC pipe formers and specifies the required capacitor values for each trap. The design emphasizes a practical approach to achieving multiband operation with a single feedline, a common goal for HF operators with limited space. The document includes a table with antenna segment lengths for each band, allowing for precise replication of the design. It also offers insights into tuning and adjustment, ensuring the antenna performs optimally across the designated amateur radio bands.

Loop Antenna Basics and Regulatory Compliance for Short-Range Radio

Hi-Z Antennas offers specialized high-impedance receiving systems, primarily focusing on phased vertical arrays for HF reception. Their product line includes preamplifiers designed for shortened vertical antennas, featuring optimized 15dB gain and array-matched characteristics. These components are engineered to enhance weak signal reception and improve signal-to-noise ratio across the HF spectrum. The company provides controllers for managing multiple vertical elements in a phased array configuration, enabling directional reception patterns. These systems are particularly effective for mitigating local noise and interference, a common challenge in urban and suburban operating environments. Specific offerings include solutions for 160-meter and 80-meter bands, addressing the unique requirements of low-band DXing. Technical details often reference components like the 2N3866 transistor in preamp designs and discuss concepts such as out-of-band attenuation. The focus remains on optimizing receiving antenna performance through impedance matching and active amplification, rather than transmit capabilities.

The 160 meter ground plane is constructed from #10 stranded insulated wire available in most hardware stores. The feedpoints / tiepoints use PVC pipe T-sections Article by W1TR

This is another alternative home-brew center connector for a dipole. The parts used are common PVC accesories found at the home supply store.

Based on a simple project based on a 2 elements Yagi for 20m band, and then becomed a triband yagi with a open-sleeve feed system

Discussion at eham about wire size used in wire antennas, and how it affects the gain of the antenna

W0IPL article on NVIS Antenna

This antenna article is geared towards new Hams and antenna builders looking for a very inexpensive 6 band antenna that can be efficiently fed with 50 ohm coax without a tune

Since they were first described by the French mathematician Benoit Mandelbrot in the mid-1970s, repeating geometric figures known as fractals have fascinated computer scientists, mathematicians and graphic artists.

Slot cubes are folded skeleton slot antennas with widened, folded dipoles bent into a cube to reduce size. QST Article 12 2019

A 38-foot Tristao Tower, similar to the U.S. Tower HDX538, was installed twice by the author, first in 1980 and then reinstalled in 1989. The resource details the challenges of self-performing heavy construction tasks like breaking concrete and digging a 3' x 3' x 6' deep footing, contrasting it with hiring professionals for the second installation. It highlights the financial and physical costs associated with DIY tower foundation work, noting a rebar cage cost of $65 in 1980 versus $150-$175 today, and the expense of tools for bending rebar. The content emphasizes the critical importance of obtaining building permits, recounting how a permit in Buena Park, California, nullified a neighbor's complaint about TVI. It also discusses the necessity of adhering to local building codes, such as the 1975 UBC and the subsequent 1985 UBC recertification requirement, which reduced the allowed antenna wind loading from 30 square feet to 20 square feet for the author's _KT34A_ Yagi. The footing depth also increased from 6 feet to 6.5 feet under the newer code. Practical advice includes hiring licensed contractors for specialized work, delaying antenna installation for a month after raising the tower, and verifying buried utilities before any excavation. The author provides specific examples of utility location services like _DigAlert_ in California, underscoring the legal and safety implications of neglecting this step. The narrative is grounded in personal experience, offering a realistic perspective on tower projects.

Description and simulation of two types of rhombic antennas, using the software 4Nec2: the simple bi-directional and the terminated directional rhombic antenna

Experiences with Loop antennas at G3YMC include some loop antenna tests and theory by G3LHZ

A nice post on Make: on homebrewing a multiband antenna for amateur radio portable operations

The HyGain LJ-153BA a monoband 3 element Yagi, designed for the 15 m band 21.00 - 21.45 MHz

A ten element ultra-lightweight yagi beam antenna for 144 MHz based on YU7EF design concept

The Patch Antenna Array was constructed and used for various satellite up and down links at my previous residence in Melbourne, Victoria from 2003 - 2007

Ten essential tips and truisms for understanding HF antenna: Non-resonant wire dipole antennas fed with open-wire line and an antenna tuner can function effectively as multiband antennas, as detailed in "The Classic Multiband Dipole Antenna" by WB8IMY in March 2004 QST. Coaxial cable, unlike balanced parallel-wire feed lines, can cause RF to travel on the outer shield braid, leading to RF feedback to the station; a 1:1 balun at the dipole center can mitigate this by isolating the unbalanced coaxial feed line. Antenna gain is achieved by shaping and directing RF energy, with beam antennas concentrating power in a specific direction, and wire antennas also exhibiting shaped radiation patterns. An antenna tuner's primary role is to match the transceiver's 50-ohm output to the antenna system's impedance, allowing modern transceivers to deliver full power. Wire antennas do not always require center feeding; end-fed long wires or off-center-fed dipoles (like the Windom) can be used, though they often necessitate an antenna tuner and a counterpoise or radial network. Dipole antennas do not need to be perfectly horizontal; their legs can be bent or inclined, which affects feed point impedance and may require SWR experimentation with coaxial feed. Vertical antennas shorter than a half wavelength require an efficient ground system, typically comprising elevated or buried radial wires, with more radials generally leading to better efficiency. A 1:1 SWR indicates an impedance match but does not guarantee antenna efficiency; an inefficient vertical antenna with a poor ground system can show a low SWR while wasting most RF as heat. Investing in high-quality, low-loss feed line, especially coaxial cable, is crucial for maximizing RF signal transfer and overall antenna system performance.

A 17 3/4-inch radiating element and 18 3/4-inch ground plane radials form the basis of this quarter-wave ground plane antenna for 2 meters FM. The design, attributed to AA1PG, utilizes a panel-mount SO-239 UHF connector and three lengths of #12 copper wire, with a total material cost estimated at $3.00. Construction involves soldering the elements directly to the SO-239, emphasizing thorough solder flow for robust connections. Recommended feedline includes _RG-8X_ for longer runs, with _RG-58_ acceptable for shorter lengths, cautioning against _RG-174_ for VHF applications due to high loss. The antenna is designed for elevated deployment, such as in trees or on roof gables, to maximize line-of-sight propagation. It aims to improve repeater access compared to typical rubber duck antennas, even with low power output.

Constructing a mobile HF antenna presents unique challenges, particularly when aiming for multiband operation and robust mechanical stability. This project details N1GY's adaptation of the KM4IE $20 antenna and the _Texas Bugcatcher_ design, focusing on practical build considerations and on-the-road performance. The author shares insights from winding coils on 2-inch PVC forms and integrating a salvaged fiberglass core from an old Hamstick-style antenna to enhance structural integrity, preventing potential failures from stress on PVC joints. N1GY's build includes a custom matching coil and a commercially sourced MFJ loading coil, carefully integrated into the design. The article provides specific tap settings for bands from 75 meters to 15 meters, achieving SWRs as low as **1.2:1** on 40 meters and **1.6:1** on 75 meters. Mechanical testing involved driving at speeds up to 70 MPH on Interstate routes, confirming the antenna's durability and the effectiveness of its PVC brace system. Further modifications address real-world usability, such as simplifying antenna removal for car washes. The ground strap was updated with a Power Pole connector, and the brace attachment to the luggage rack was converted to wing nuts, reducing removal time from 30 minutes to approximately _five minutes_. This iterative design process highlights practical solutions for mobile HF operation.