Search results

The **DF9CY Three-Element Antenna for 28 MHz** details the modification of a commercial PAN International CB antenna to optimize its performance for the 10-meter amateur radio band. This resource provides specific design parameters, including a design frequency of 28.300 MHz, a usable bandwidth of 600 kHz, and a return loss better than 20 dB centered at 28.270 MHz. It also specifies a gain exceeding 7.5 dBi and a front/back ratio greater than 20 dB. The feeding mechanism utilizes a **gamma match**, with setup instructions provided for its positioning. Modifications involved shortening each element's end by 40 mm, a straightforward process due to existing screw holes. The author also recommends replacing the original screws with V2A stainless steel hardware to prevent oxidation and upgrading the SO239 connector to an N-connector for improved reliability. EZNEC simulation files are available, showing azimuth and elevation diagrams with good front-to-back ratio and around 10 dB vertical attenuation. The antenna has been in service since October 1998, demonstrating good performance with 90 watts and even 750 watts, facilitating contacts with all continents from a modest 9-meter height.

A multi band inverted delta loop antenna project that can be used from 40 to 10 meters band with full details and analysis of antenna performances on each band, document includes EZNec reports and setup pictures

Hexagonal Wire Beams for 40-10m from DL7IO, different mono/multiband designs with building descriptions and model files for EZNEC

HF Wire Yagi antenna with notes and eznec file on original article of a Portable 3-Band Yagi antenna for 10-15-20 meter band made with wire elements. Include link the original to QST article.

Baluns what do they do, in a pdf file by W7EL

M1PAF's 20 Meter Vertical Moxon antenna design, based on Pete Mills' EZNEC model, utilizes a push-up GRP mast and Tufnol plate for mounting cross arms, minimizing metallic elements within the beam. Hydraulic pipe clamps, also plastic, secure the tube clamps, with only two bolts and a plate being metallic. Dog bone insulators with Kevlar line and snap links facilitate quick wire element attachment, ensuring tension in all dimensions. The antenna's support structure includes Tufnol guying rings for Kevlar guys, providing stability against high winds. The cross arms are constructed from three 1-meter sections, allowing for convenient packing. This portable setup was successfully deployed adjacent to the ocean, enabling over 4500 QSOs in six days with 100W, achieving easy contacts into Japan and Asia. The design emphasizes ease of erection by a single operator and robust performance in challenging environments. Components for the cross arms were sourced from Spiderbeam. Further information is available via M1PAF's QRZ.com details.

Indoor multiband dipole with EZNEC data files for simulation and analysis. Includes details on construction, tuning, SWR plots, and software usage. This page includes two different dipoles, a first version for 20-10 meters and an extended version covering 40-10 meters allowing a full coverage of most used ham radio HF Bands.

The ARRL ANTENNA Vol 5 COMPENDIUM features an article detailing two portable 6-meter antennas: a 2-element quad and a 3-element Yagi with telescoping elements. The 2-element quad exhibits a measured gain of **4.2 dB** over a dipole, while the 3-element Yagi achieves **5.8 dB** over a dipole. Both designs prioritize ease of construction and rapid assembly/disassembly for portable operations. Specific dimensions are provided for a 3-element 6-meter quad using #14 bare copper wire. The reflector element diameter is 6.2958 meters, the driven element 6.125 meters, and the director 5.8547 meters. Element spacing is 0.9398 meters between reflector and driven, and 1.1684 meters between driven and director. The SWR is under _1.26:1_ from 50 to 50.4 MHz, with a feed point impedance of 48.75 -j0.13 Ohms at 50.2 MHz, suitable for direct 50 Ohm coax feeding with a current _balun_.

MoxGen is a **Windows** application designed to calculate dimensions and generate antenna model files for 50-ohm **Moxon Rectangle** antennas. Users input the desired design frequency in MHz and the wire size (AWG or diameter in inches/mm), and the software outputs the precise element lengths, spacing, and overall dimensions required for construction. It also creates a .maa file compatible with EZNEC, enabling further analysis and optimization of the antenna's performance characteristics. The software provides a visual representation of the Moxon rectangle, displaying key parameters such as gain, front-to-back ratio, and SWR at the design frequency. This allows radio amateurs to quickly assess the potential performance of their proposed antenna before physical construction. The generated EZNEC model facilitates detailed pattern analysis, impedance matching, and interaction with surrounding structures, proving useful for both initial design and fine-tuning.

A 40-meter reversible _Moxon rectangle_ antenna project details its construction and performance, featuring 51-foot long sides and 7.7-foot turned-in sections. The design incorporates a 16.5-foot boom, with elements spaced 1.1 feet apart, constructed from #14 covered wire. It utilizes two double-pole relays for switching between NE and SW directions, achieving F/B ratios up to 40 dB on CW and 30 dB on SSB, with distinct reflector stub settings for each mode. This antenna replaced a full-size 2-element Yagi, demonstrating comparable forward gain while offering superior F/B ratios and directional flexibility. _EZNEC_ modeling indicates only 0.2 dB less forward gain than the Yagi. The system uses no baluns, relying on half-wave feedlines and switched stubs for impedance matching. The antenna is tree-supported at 45 feet, with its effective radiation height modeled at 80 feet due to local terrain, enhancing its performance over a nearby lake.

The provided resource offers a downloadable ZIP archive, "6 meter moxon.zip," containing comprehensive design files for a **6-meter Moxon antenna**. Specifically, it includes antenna models in EZNEC format, allowing radio amateurs to simulate and analyze the antenna's performance characteristics. The archive also features detailed drawings, photographic documentation of the construction, and various plots illustrating the antenna's radiation patterns and impedance matching. Authored by Allen Baker, KG4JJH, the content focuses on a horizontally polarized Moxon antenna optimized for 50.5 MHz. The EZNEC files, such as "Moxon 6m 50.5 MHz H-POL.EZc," provide precise geometric and electrical parameters for replication or modification. The collection of files, totaling approximately 10 MB, serves as a practical guide for hams interested in building or understanding the design principles of a compact, directional 6-meter antenna, presenting both theoretical models and visual construction aids.

This technical note explores the application of **Moxon rectangle** antennas for WARC bands, specifically 17 and 12 meters, as compact directional alternatives to standard Yagis. It details three design approaches: a dual-band Moxon using open-sleeve coupling, a Moxon-Yagi combination, and a simplified 1.5 Moxon rectangle. The document provides specific dimensions in feet for aluminum tubing elements (0.75" and 0.5" diameter) for each configuration, along with projected free-space gain, front-to-back ratio, and feedpoint impedance (R+/-jX Ohms) across the respective band segments. Performance tables illustrate gain (dBi), front-to-back ratio (dB), and 50-Ohm VSWR for each design. The dual-band Moxon, despite its compact 7-foot boom, is not recommended due to extreme sensitivity to construction variations, leading to rapidly changing performance characteristics. The Moxon-Yagi combination, featuring a 17-meter Moxon and a 12-meter director-driver Yagi, is presented as a more practical and adjustable solution, offering stable performance with a 10-foot boom. NEC model descriptions are included for simulation in programs like EZNEC, NEC-Win Plus, AO, or NEC4WIN.

A delta loop antenna for 17 meters band include eznec antenna model file

Hexagonal wire beams for all hf bands, technical resource, EZNEC files, tools for antenna modeling and documentation. You can also order parts to build your own antenna.

Designing **Moxon Rectangle** antennas often involves an urge among builders to find simple "magic formulas" for element lengths. L. B. Cebik, W4RNL, argues against this simplistic approach, emphasizing that antenna dimensions do not scale linearly and are influenced by factors like wire size and height above ground. This resource presents a procedure for developing sensible design equations, starting with uniform-diameter elements and perfectly conductive materials, with adjustments for real-world materials like copper and aluminum. The core of the method involves judicious **NEC modeling** (versions 2, 3, or 4) to create a baseline dataset for regression analysis, ensuring models meet specific performance standards for gain, front-to-back ratio, and feedpoint impedance. The derived equations, presented as a BASIC program, allow for calculating Moxon dimensions (A through E) based on wire diameter in wavelengths and design frequency. W4RNL demonstrates the efficacy of these equations by designing and testing Moxon Rectangles for 7.15 MHz (AWG #12 wire), 28.5 MHz (1" tubing), and 146 MHz (0.125" rod). Modeled performance data, including gain, front-to-back ratio, and feedpoint impedance, are provided for both perfect and real-world materials, showing high efficiency and close adherence to design goals. The article also references a standalone Windows program by AC6LA that automates these calculations and generates EZNEC or NEC models.

Demonstrates the design and construction of a 9-element Yagi antenna for the **70 cm band** (432 MHz), based on the DK7ZB concept. The resource details EZNEC+ calculations for a single antenna, providing gain, sidelobe suppression, and front-to-back ratio figures. It also presents a comprehensive analysis of stacking two such antennas, including optimal stacking distance (1000 mm) and the resulting performance enhancements for the stacked array, such as an increased gain of 17.03 dBi. The article includes detailed drawings, wire file dimensions in millimeters, and azimuth/elevation plots for both single and stacked configurations. Practical construction steps are documented with original photographs, illustrating element mounting, the **28 Ohm matching system** using two quarter-wave 75 Ohm transmission lines, and the critical N-connector wiring. It also covers the iterative process of fine-tuning the driven element length to achieve a return loss of 20 dB, validating the EZNEC+ simulation results with actual measurements.

The resource details the construction of a 6-meter _Moxon_ antenna, presenting two distinct versions: one horizontally polarized for 50-51 MHz CW/SSB and another vertically polarized for 52-54 MHz FM. It specifies the use of 5/8 inch OD and 1/2 inch OD aluminum tubing, with 3/8 inch OD solid aluminum for corners, and provides a comprehensive material cutting schedule. The design aims for robust, portable construction, with all materials costing under $100. Detailed drawings and EZNEC models are referenced for precise dimensions and assembly, ensuring accurate element spacing and impedance matching. The EZNEC model for the H-POL version predicts a gain of **11 dBi** and a front-to-back ratio of **25 dB** at 50.5 MHz, while the V-POL version shows a gain of **6.7 dBi** and a front-to-back ratio of **36 dB** at 53 MHz. The article includes practical SWR measurement advice, noting the impact of coax length and loss on analyzer readings. Field tests during a tropical storm demonstrated the antenna's durability and performance, yielding numerous contacts across significant distances, including California, Colorado, and Texas, on SSB and PSK.

The Moxon Beam, introduced by L. Moxon (G6XN), is a compact 2-element Yagi featuring a radiator and reflector with reduced dimensions, approximately 75% the size of a full-size beam. This design utilizes bent element ends for capacitive loading, which is superior to inductive loading with coils, resulting in greater bandwidth and lower losses. DK7ZB details that while the gain is slightly lower (0.5-0.7 dB) than a full-size beam, the _Moxon_ offers an exceptional front-to-back (F/B) ratio of 30 dB or more on its design frequency, surpassing other 2-element beams. The article provides specific dimensions for building wire _Moxon_ antennas for bands from 30m down to 10m, and also mentions a 2-m-Moxon. Construction guidance includes using fishing rods for lightweight spreaders and an aluminum tubing spider for support. The resource highlights the utility of _Moxgen_ by AC6LA, a freeware program that simplifies Moxon beam design and generates EZNEC output files for further analysis and tapering modifications. DK7ZB emphasizes that the design frequency should be set at approximately one-third from the band's beginning to optimize SWR performance, as SWR tends to rise more significantly below the design frequency. The bandwidth for SWR < 1.5 is noted as sufficient for ranges like 28.0-28.7 MHz and 21.0-21.45 MHz when constructed with aluminum tubes, though wire beams exhibit a narrower bandwidth.

The GW3YDX Super Moxon antenna design improves upon the standard Moxon Rectangle by incorporating additional directors in a rectangular configuration, yielding enhanced directivity and gain. For the 6m version, modeling with 4NEC2 and EZNEC+ indicated a 3dB gain increase and a 26.5dB front-to-back ratio, with VSWR below 1.5:1 between 50.0 and 50.3MHz when optimized for 50.1MHz. This design achieves a narrower -3dB power point beamwidth of 60° compared to the original Moxon's 80°, contributing to better QRM rejection. The boom length for the enhanced design is just under 2m, approximately double the original Moxon's, with no increase in wingspan. Construction details include tubing lengths for 6m, 4m, and 2m versions, with specific dimensions provided for elements A through M, measured to tubing centers. For instance, the 6m version uses a 2160mm element A and a 2140mm element H. The design maintains a 50-ohm feed impedance, with practical models showing VSWR plots consistent with simulations after minor adjustments to driven element lengths. The article also references Moxgen software for initial Moxon parameter calculation and NEC/EZNEC model generation. The 2m Super Moxon version measures approximately 30" x 25", demonstrating the compact nature of the design across different VHF bands. The article highlights the antenna's performance in real-world DX contacts on 6m, achieving contacts with over 80 stations in the USA from a modest QTH.

Presents the construction of a 6-meter (50 MHz) Moxon wire beam antenna, detailing the use of #14 AWG THNN stranded wire and a treated wood frame. It covers the assembly of a galvanized pipe mast, emphasizing the use of pipe sleeves for joint reinforcement over threaded couplers to prevent breakage during raising and lowering operations. The resource also describes the integration of a 1:1 current balun, rated for 50-54 MHz, and the use of RG-8X coax for the transmission line, recommending low-loss alternatives like Belden 9913-7F. Further, it outlines a manual rotation mechanism using pipe hanger clamps and carriage bolts for true North orientation, incorporating magnetic declination calculations from NOAA. The antenna's performance is discussed, noting good gain and take-off angle, with SWR tuning facilitated by a Palstar AT-500 manual tuner. An EZNEC+ 5.054 model for the antenna is available for download, alongside predicted radiation patterns and SWR curves, compared with actual AIM-4170C measurements.

A Loop Fed Array Yagi antenna for 50 MHz featuring 11 dBi gain and 23 f/b ratio. In this excellent page the author even includes a detailed drawing in DWG format, with element lenght and spacing measures, in a separa file a full list of material list needed to build this yagi antenna including source and price, the EZnec file for this antenna plan, and a lot of pictures of this LFA Yagi for 50 Mhz. A ten page PDF file containing all infos, is also available to download.

The ZS6BKW multiband antenna, an optimized variant of the classic G5RV, features a 102-foot (31.1 m) horizontal span and a 39.1-foot ladder line matching section. This design, derived by G0GSF (formerly ZS6BKW) in the early 1980s using computer programs and _Smith charts_, aims for improved SWR across multiple HF bands compared to its predecessor. Construction details specify Wireman 554 ladder line and #14 AWG THHN copper wire for the radiators, with precise instructions for determining the velocity factor (VF) of the ladder line using an antenna analyzer or dip meter, ensuring accurate physical length for the matching section. The radiator length is electrically 1.35 wavelengths for the 20-meter band, requiring careful trimming during tuning. Field measurements with an _AIM-4170C_ analyzer by KI4PMI and NC4FB demonstrated good SWR curves and bandwidth on 6, 10, 12, 17, 20, and 40 meters. The antenna was deemed unusable on 15 and 30 meters due to very high SWR, but an LDG AT-100PRO autotuner successfully brought 6 and 80 meters into tune. Contacts were made on 80, 40, 20, and 17 meters, including a **17-meter** contact to Spain. EZNEC models for 80-6 meters are provided, along with an AutoEZ model by AC6LA, which predicted good SWR for 80-10 meters. W5DXP's modifications for an all-band HF ZS6BKW are also referenced.

The ZS6BKW multi-band antenna, an optimized variant of the classic G5RV, is presented with detailed construction and tuning instructions. This resource outlines the antenna's design principles, which were developed by _Brian Austin (G0GSF)_ using computer programs and Smith charts to achieve optimal dimensions. It provides specific guidance on calculating and adjusting the lengths of the radiators (L1) and the matching ladder line (L2), emphasizing the critical role of velocity factor (VF) in achieving resonance. The article includes a step-by-step procedure for empirically determining the VF of ladder line using an antenna analyzer, ensuring accurate physical lengths for the matching section. It details the tuning process for the radiators, offering practical tips for incremental adjustments to achieve the best SWR curve. The resource presents SWR measurement results obtained with an _AIM-4170C_ analyzer across multiple bands, alongside predicted SWR graphs from an AutoEZ model. It confirms successful contacts on 80, 40, 20, and 17 meters, including a **17-meter DX contact** to Italy. EZNEC and AutoEZ models for the ZS6BKW antenna, covering 80 through 6 meters, are provided for download, allowing further analysis and customization. The document specifies component details, such as the use of Wireman 554 ladder line and #14 AWG THHN copper wire, and discusses the antenna's performance characteristics, noting high SWR on 15 and 30 meters but successful tuning on 6 and 80 meters with an external tuner.

A 5 element yagi beam antenna for ten meters band with full dimentsions, eznec file and coax match informations for 50 ohms feed line

EZNEC Simulation files collection by DF9CY

Presents an alternative construction method for isolated element Yagi antennas, specifically for VHF/UHF operation. The technique utilizes commercially available vibration damping clamps (resin support blocks) to isolate 1/4-inch aluminum rod elements from a 1-inch square aluminum boom, simplifying the build process by eliminating the need for custom-machined insulators. This approach is demonstrated through the construction of 6-element Optimized Wide-Band (OWA) Yagis for the 2-meter, 1.25-meter, and 70-centimeter bands, which are well-suited for portable contesting arrays due to their light weight and decent gain. The document provides detailed specifications for element and boom materials, along with step-by-step procedures for cutting, drilling, and tapping. It also covers the fabrication of a feedpoint bracket for a direct 50-ohm SO-239 coax connection and discusses considerations for horizontal versus vertical polarization, including mast placement. The resulting 6-element models achieve an average free-space gain of 10.2 dBi and a 25 dB front-to-back ratio, with the construction technique being scalable for higher gain designs. Included are parts lists with sources, detailed mechanical drawings for each band, and EZNEC data for the 2-meter and 70-centimeter designs, showing both free-space and 30-foot elevation performance. The designs are optimized from W4RNL's original concepts using HAMCALC, ensuring good gain, passband characteristics, and front-to-back ratios for wideband Yagi operation.

AutoEZ, Automated use of EZNEC, is an Excel workbook that works alongside EZNEC antenna modeling software version 5.0 or later. With AutoEZ, you can control different aspects of your model using variables and run multiple EZNEC test cases automatically. Formulas in Excel allow you to modify any part of the model. AutoEZ's interface resembles EZNEC's. Enabling macros in Excel might be necessary before using AutoEZ. The program opens various model file formats including EZNEC (.ez), NEC (.nec or .inp), AO and NEC/Wires (.ant), and MMANA-GAL (.maa). You can set the frequency and/or variable values for the test cases to be run through EZNEC. AutoEZ allows you to create animations showcasing how the pattern changes as the model configuration is modified. You can download a fully working, but limited demo copy from this site.

Details the construction of a portable 6-meter 4-element quad antenna, specifically designed for VHF and Field Day operations. The design emphasizes portability and rapid field assembly, utilizing a 10-foot boom, #12 bare wire elements, and fiberglass electric fence post spreaders. It presents specific dimensions for reflector, driven element, and directors, including spreader lengths, circumferences, and corner marks, all derived from a G0KSC design and modeled in EZNEC. The resource outlines the fabrication of synthetic lumber hubs that allow post-assembly adjustments along the boom, and describes spreader clamps made from ¾” OD fiberglass rod, drilled and tapped for 8-32 nylon thumbscrews to secure element wires. It provides instructions for reducing spreader ends to 0.370” OD for proper fit and details the assembly of the boom from two 1½” OD x 6’ aluminum tubes. Performance data from EZNEC modeling indicates a gain of 10.25 dBi (8.1 dBd) and a 20 dB F/B ratio at 50.150 MHz, with SWR values of 1.08, 1.09, and 1.11 at 50, 50.15, and 50.5 MHz respectively. The document includes a field test report from Field Day 2010, where the antenna was deployed at 21 feet, showing an SWR resonance 200 KHz below EZNEC predictions. It notes successful 5-watt QSOs into New York and Canada from Tennessee, highlighting the antenna's excellent directivity and gain compared to a 4 dBd Moxon. The antenna breaks down into easily transportable components, including two 5’ boom sections, a 3’ boom connector, 16 spreaders, and four element/spreader clamp assemblies.

This document provides comprehensive guidance on modeling and constructing multiband dipole antennas using traps. It addresses common segmentation issues in EZNEC modeling software, recommends optimal segment lengths for trap models, and compares trapped dipoles with paralleled multiband dipoles. While trap dipoles are significantly shorter, they exhibit lower gain and narrower bandwidth. Detailed instructions for building weatherproof coaxial traps include material lists, construction steps, and tuning methods. The guide notes that properly constructed coaxial traps introduce only minimal signal loss (0.6 dB) while offering practical multiband performance in a compact design.

The article discusses the evolution of antenna designs, specifically focusing on the upgrade from the W7IUV rotatable Flag to the Waller Flag. Author Pierluigi Mansutti IV3PRK shares insights on modeling these antennas using EZNEC software, detailing their performance in noisy environments. The W7IUV Flag proved effective for receiving signals, while the Waller Flag, developed by NX4D and N4IS, offers improved front-to-back ratios but requires careful consideration of signal levels and noise management. The article emphasizes practical modeling results and interactions between different antenna setups.

This article demonstrates how to convert an existing tower into a dual-band vertical antenna for 80- and 160-meter DX operation. Using EZNEC modeling and practical design principles, the authors achieved a low-profile, efficient setup with a single coax feed line, no moving parts, and optimal radiation patterns. The system integrates an 80-meter vertical wire and a 160-meter shunt-fed gamma match for simultaneous operation. Detailed construction insights, including feed system and capacitor configurations, offer a reliable, full-legal-power solution.

This article explores the powerful features of AutoEZ as an Excel application working with EZNEC antenna modeling software. The article demonstrates how variables, equations, and formulas enable versatile antenna design and automatic optimization. Through practical examples including dipoles, inverted vees, delta loops, and monopoles, the author shows techniques for achieving resonance, implementing transmission line resonators for broadbanding, and optimizing antennas across frequency ranges. The step-by-step demonstrations cover unit conversion, coordinate calculations, segmentation considerations, and SWR optimization. This practical guide illustrates how AutoEZ extends EZNEC's capabilities, making complex antenna modeling more efficient and accessible.