Search results

by Adam M. Farson VA7OJ/AB4OJ

This is an Excel spreadsheet template to design DL6WU Yagi antennas

Phased vertical antenna system in french

The **70cm Moxon Beam** project outlines the construction and testing of a compact, directional antenna for the 432 MHz band. G3XBM recounts his early 1980s experience with a 4W FM321 transceiver and a Jaybeam 48-element TV antenna, which provided a baseline for his later UHF antenna experiments. This project focuses on a simpler, yet effective, design for local and regional contacts, emphasizing ease of construction and practical field results over complex theory. The article details the specific dimensions and materials used for the Moxon rectangle, including 6mm diameter aluminum tubing for the elements and a PVC boom. G3XBM notes that the antenna was built for portable use, making it lightweight and easily deployable for field operations. The feedpoint impedance was measured at 50 ohms, ensuring a direct match without the need for an external tuner, which simplifies setup. Performance tests included comparisons against a commercial 5-element Yagi, revealing that the Moxon provided comparable forward gain and an excellent front-to-back ratio, crucial for reducing local QRM. The author's observations confirm the Moxon's reputation as a robust performer for its size, suitable for both fixed and portable 70cm operations.

Slot antenna and complementary dipole

Antenna experiment - Delta Loop for 7 Mhz band by AG1LE

An easy method for erecting antenna masts using readily available material

The page discusses Axial-Mode Helical Antennas, focusing on turning helical antennas over perfect ground and modeling helices in NEC-2 for optimized design. It covers topics such as high-gain performance, broadband, impedance matching, radiation pattern, feedline, balun, near field, far field, and DIY applications.

A 2 meter antenna made of copper tubes, offering circular polarization

A german documento on magnetic loop antennas

The aim of the project is test if fractal antennas can work acceptably on HF bands.

Homebrew Wifi antenna test page

G3TPW CobWebb Antenna for the 14, 18, 21, 24 and 28 MHz Bands

A Moxon rectangle antenna design for the 11-meter band is presented, offering a compact and lightweight solution for directional HF DX operation. This two-element parasitic array, popular among amateur radio enthusiasts, provides considerable directional gain and lower noise on horizontal polarization. The design is suitable for both 27 MHz Citizens Band (CB) and the lower portion of the 28 MHz amateur radio band, making it versatile for operators interested in either service. Construction can utilize materials like bamboo, squid poles with wire elements, or aluminum tubing on a central boom. The article includes a plan view diagram with specific dimensions (A-E) in centimeters and inches for building the antenna, such as a 392.09 cm (154 3/8 inch) driven element. The Moxon configuration inherently presents a 50 Ohm load to the transceiver, often eliminating the need for an external matching unit or balun. Performance data for an antenna mounted at approximately 30 feet indicates a gain of 10-11 dBi and a frequency range of 27.300 MHz to 28.300 MHz. The design is noted for its excellent front-to-back rejection, with tested signal drop-offs from S5-S7 to S2 when turned, demonstrating effective suppression of unwanted signals.

This article describes the 144MHz horizontally polarised antenna at VK1OD in November 2008. The antenna uses two identical four element arrays that were constructed around 1970

The problem with making your own trapped HF antennas is usually getting the coaxial traps tuned to frequency.

About HF Wire Antennas for field day or any day a basic wire antenna article

Demonstrates the product line of _LZ Antenna Ltd._, a Bulgarian manufacturer specializing in amateur radio antennas and custom electronic devices. The company focuses on robust, high-quality HF multiband Yagi and vertical antennas, leveraging over 20 years of experience from founder Georgi Georgiev in radio amateur development. Featured models include the LZA 8-4, LZA-10-3, and the LZA-7-3A WRTC 2022, alongside various rotary dipoles like the LZA1 40/30m. Provides specifications for several Yagi antennas, such as the LZA-9-5, LZA-13-7, and LZA-6-3 (a 6-element, 3-band design). The company emphasizes applying "leading edge technology" to high-frequency communication equipment production, with products designed for durability and performance. The LZA-10-5 Yagi offers **12.5 dBi** gain on 10m, while the LZA-13-7 provides **13.2 dBi** on 20m, showcasing competitive gain figures for DXing and contesting.

Helical antennas have long been popular in applications from VHF to microwaves requiring circular polarization, since they have the unique property of naturally providing circularly polarized radiation. Paul Wade W1GHZ

A vertical portable antenna system by W0SJS that will work on 40, 30, 20, 17 and 15 meters

A 10 meters band Slim Jim antenna project, made with a 450 Ohm slotted ribbon cable and secured on a 8 m fishing pole, by Steve G0KYA

This HALO design is not ground dependent and can be mounted atop a section of PVC.

Presents a construction project for a linear-loaded 40-meter rotatable dipole, detailing the design evolution from mid-element coils to 300-ohm twinlead loading. It covers material selection, including repurposed fishing poles and EMT conduit, and outlines the assembly process for the antenna elements and mounting plate. The resource provides specific measurements for element lengths and linear loading sections, along with SWR plots demonstrating the antenna's resonance at 7.035 MHz with a 1.1:1 SWR, and bandwidth up to 7.120 MHz below 2:1 SWR. The article documents the antenna's performance during various RTTY and CW contests, including the SARTG RTTY and SCC RTTY contests in August 2006, and the ARRL DX CW and CQWW WPX RTTY contests in February 2007. It reports successful operation at 500-1000W, noting improved performance after replacing a faulty coax cable. Specific DX contacts from British Columbia, including stations in Europe and South Africa, are listed, illustrating the antenna's capability despite its shortened length and relatively low height of 55 feet. The content highlights practical considerations such as weatherproofing the connections and supporting the fiberglass elements to prevent sagging. It also includes a brief comparison to an inverted-V at similar height and a ground-mounted vertical, noting the rotatable dipole's quieter reception. The author shares insights into the iterative design process and tuning adjustments made to achieve optimal resonance.

New type of a Quad antenna, 6.4dBd gain

Various publications through the years have shown how the SWR measured on a shorted (or open) feed line can be used to calculate feed line attenuation

By Guy, de ON6MU, At VHF, both the 1/4-wavelength monopole and the 5/8-wavelength monopole antennas are widely used.

W4ZT used this antenna for Field Day and other portable applications. He built them for all bands between 160 meters and 6 meters. You can make them easily using whatever wire you have available and make the insulators from scrap plastic

Stacking 2 Meter Halo Antennas by Mike Fedler N6TWW

A 4 way remote antenna switch project

Constructing a portable, high-gain antenna for _AO-40_ satellite operations presents unique challenges, particularly regarding mechanical stability and parabolic accuracy. This resource details the build of a 1.2-meter "brolly dish" antenna, utilizing a non-conducting fiberglass umbrella frame as its foundation. The project outlines a method for achieving a parabolic shape using stressed aluminum fly screen mesh, guided by practical geometry and a temporary dowel template. Key steps include selecting an appropriate umbrella with a suitable f/D ratio (ideally >0.25), removing the original fabric, and precisely cutting and attaching eight segments of fly screen to the struts to form the reflective surface. The construction process, which took approximately five hours for the author, _G6LVB_, resulted in a dish with an f/D of 0.27 (depth=270mm, diameter=1160mm, f=310mm). The article also describes a modification to a _TransSystem AIDC_ feed, incorporating a PCB reflector behind the dipole for easier mounting. Performance tests at a squint angle of 15 deg and a range of 50,000km yielded a signal-to-noise ratio of 33dB on the S2 beacon and 23dB for SSB signals, indicating strong reception. The author notes that the modified umbrella may not close fully without risking surface disfigurement.

There is considerable confusion as to what exactly a multiband vertical antenna is. The confusion concerns the method of feed, how much mismatch one can expect, how many radials are required, how the particular antenna is built for multiband use, plus some other points.

Antenna mounting height, the higher the better? Learn how radiation pattern change, and decide if you need an higher or a lower angle for your dx needs.

The Truth about the G5RV Antenna, how to optimize the design to be more efficient on all bands

Lowering an NVIS or N.V.I.S. antenna very close to the ground enhances NVIS operation

The WT0G crazy W dipole, a solution for 160 meter operations

A 20-meter vertical _Moxon_ antenna, designed for portable operation, is detailed with specific dimensions for its driven and reflector elements. The project outlines the construction process, including the use of PVC pipe for the frame and #14 AWG insulated wire for the elements. The antenna's compact size and directional characteristics make it suitable for field day operations or limited space environments, offering a gain of approximately 5.5 dBi and a front-to-back ratio of 20 dB. Testing revealed a 1.2:1 SWR at 14.250 MHz, demonstrating good impedance matching across the target frequency range. The _Moxon rectangle_ design provides a clean radiation pattern with minimal side lobes, which is advantageous for reducing QRM from unwanted directions. This build offers a practical solution for hams seeking a lightweight, easily deployable directional antenna for 20 meters without the complexity of a full-sized Yagi.

A project of a vertical and wires that generate a multiband antenna for 28 14 10 and 7 Mhz in french

The G5RV JR cover 10-40 meters band a project by PU2OKE

This antenna was described by Bill, G4KIH in Sprat 52 and is actually a G5RV modified to fit into a small space.

A project of a semi vertical trap antenna that can be tuned for 7 bands

How to homebrew a ENVIS antenna for 80 and 40 meters band

A 160 meter antenna with a base loading coil used to tune the two lower frequency segments of the band.

A Quad Loop antenna for 17 meter band

Antenna tests on Alford 1.2 Ghz for ATV oprations in italian

Putting up wire antennas is always a fun proposition. Sometimes it is fun for the participants and often fun for on-lookers. There are at least as many methods as there are folks putting up antennas.

Review by G3TXQ and comparison to its modificated versions. SWR Measurements on inverted V setup and comparison from EZNEC model and a real one.

A monoband J pole antenna dimensions sheet by N6JSX

The SARK100 Antenna Analyzer it is yet another antenna analyzer but available in kit form and designed to be easy to assemble and with an affordable pricing.

The Pocket Loop is a small magnetic loop antenna designed for a carry anywhere operation, it disassembles in 33 centimeters pieces that can be carried even on an attach handbag.