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Comprehensive information page about bi-directional Beverages, including applications, construction details, and tips.

This antenna is intended for the 20-meter Band. There are two Voltage Fed Helical Dipoles, made with 2 slinky that fed with phase shift in 90 degree

This PDF document details the construction of a **70 MHz** Big Wheel antenna, a horizontally polarized omnidirectional array. The design utilizes three full-wave loops, each approximately **2160 mm** in diameter, arranged in a triangular configuration. The resource provides mechanical dimensions for the antenna elements and a comprehensive bill of materials, specifying component quantities and types, such as M8 stainless steel bolts, 15x15x1.5 mm square aluminum tubing for spacers, and 8 mm aluminum rod for the arcs. The central hub is constructed from two 160x160x8 mm aluminum plates, with four 40 mm long polyamide insulators supporting the radiating elements. The feed system incorporates a 50 mm diameter aluminum pipe for mounting and a matching stub constructed from a 120x20x2 mm aluminum sheet, connected via M8x10 mm bolts. The resource includes a diagram illustrating the mechanical dimensions and assembly points, including the N-connector fixing point and the center conductor attachment. The project was published on May 25, 2011, by Peter OE5MPL and Rudi OE5VRL. DXZone Focus: PDF | 70 MHz Big Wheel | Mechanical Dimensions | **2160 mm** loop diameter

Construction and analysis of a low cost omnidirectional horizontally polarized antenna for 144 MHz, including notes on halo antenna stacking

High quality VHF/UHF Yagi (directional) antennas

An experimental omni-directional antenna for 70cm which has both horizontal and vertical gain

Examines the design and performance of a compact, efficient multiband beam antenna, based on a modified **W8JK array** by K5LJ. The author recounts his quest for a simple, compact, and reasonably efficient beam, initially using a single delta loop for 40 meters. He then details his modeling efforts with EZNEC, focusing on a W8JK array using 20-meter dipoles, noting its venerable design history in various Antenna Handbooks and QST. The resource explains how the classic W8JK array, composed of 0.5-lambda elements at the lowest operating frequency, uses a closely spaced phasing line to connect feedpoints, often 450-ohm ladder line. K5LJ's modifications, including offsetting the feedpoint on the phasing line, resulted in surprising gain and a somewhat unidirectional pattern on 20 meters, rivaling a full-sized Yagi. The article also delves into mechanical construction details, using nested tubing and PVC pipe for element isolation, and discusses the feedpoint impedance characteristics across multiple HF bands.

Quarter wave omni-directional spider antenna for 2.4GHz 802.11b

An omnidirectional and horizontally polarized VHF antenna by EA4EOZ

About the basics of what is a discone antenna for wide band or bandwidth omnidirectional applications

Benelec Pty Ltd specializes in the design and manufacturing of **antennas** and RF components, covering a broad frequency range from 0.002 GHz to 8 GHz. Their product line includes Land Mobile Radio Antennas, such as HF 2-30MHz, VHF 40-180MHz, and UHF 200-520MHz models, alongside specialized Military Antennas for dismounted, UxS, C2, and EW applications. The company also produces Cellular Antennas, including 4G/5G and GPS/GNSS types, and Marine Antennas for both vessel-mounted and fixed-site installations. Additionally, Benelec offers a comprehensive range of coaxial cables, connectors like N-Type and SMA, and various radio accessories. The company's offerings extend to RF components such as duplexers, diplexers, and 50 Ohm loads, as well as DAS components like directional couplers and hybrid combiners. Benelec provides EMP and lightning protection solutions, including 1/4 Wave Stub protectors and replaceable GAS capsules. Their product catalog also features P25, DMR, and FM Analog radios, along with portable and mobile radio accessories like batteries, chargers, and cabled headsets. The company supports various sectors with robust communication solutions.

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.

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.

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.

This article is about a simple vertical end-fed-half-wave wire antenna for 10 meters that can be used in case of restricted space.

ITELITE manufactures omnidirectional, sector and directional antennas 900 MHz 2.4 GHz 3.5 GHz 5 GHz 5.8 GHz antennas.

Constructing an effective directional antenna for the 40-meter band presents unique challenges due to its physical size requirements. This resource details the homebrew construction of a 2-element _Moxon_ Yagi antenna specifically designed for 7 MHz operation. The author, TA7OM, provides a visual guide to building this antenna, showcasing the boom, element mounting, and feedpoint connections through a series of high-resolution photographs. While textual descriptions are minimal, the imagery clearly illustrates the mechanical aspects of the antenna's assembly. The _Moxon_ rectangle design offers a compact footprint compared to a full-size Yagi, making it a practical choice for many hams with limited real estate. The visual documentation allows builders to replicate the antenna's structure, including the use of PVC pipe for element support and the method for spacing the driven and reflector elements. The project emphasizes practical construction techniques for achieving a directional pattern on a challenging HF band, suitable for DXing and contesting.

Manufacture of microwave directional, omni directional, sector and multisector antennas with horizontal polarization for ISM band 2,4 GHz

The 60-page PDF document, "Antenna Systems and Theory For The Non-Technical Ham" by Jim Abercrombie, N4JA, provides a foundational understanding of antenna systems. It explains basic antenna theory, including how antennas work, electromagnetic wave polarization, and the role of frequency. The resource details various antenna types such as flat top dipoles, inverted-V dipoles, shortened loaded dipoles, G5RV dipoles, Carolina Windoms, and end-fed configurations. Vertical antennas, including ground-mounted trapped verticals and inverted-L verticals, are also covered. Directional beam antennas like monoband Yagis, cubical quads, and log-periodic arrays are discussed. Propagation modes, including ground-wave, direct wave, and skywave propagation, are explained in detail, with specific attention to the D, E, and F layers of the ionosphere and their effects on HF communication. Technical concepts such as standing wave ratio, decibels, resistance, and reactance are defined, along with calculations for half-wave resonant dipole lengths. The document addresses feed-line radiation, balun applications, and critical antenna and tower safety considerations. It aims to dispel common antenna myths and educate hams on making informed antenna choices.

The collinear antenna, or Marconi-Franklin antenna, is an omnidirectional, high-gain antenna composed of in-phase half-wave dipoles aligned vertically. By using quarter-wave transmission line segments, it maximizes gain at a low horizon angle, outperforming a half-wave dipole. Adding segments increases gain but narrows bandwidth. A popular DIY version, the CoCo antenna, uses half-wave coaxial cable segments connected by non-radiating transmission lines. Built with stable velocity factor cables, a matching quarter-wave sleeve balun, and ferrite rings for attenuation, the antenna achieves performance comparable to commercial models.

Simple 6 Metre DX Antenna based on an article by LB Cebick in QST May 2002 on a Quad Turnstile antenna. This antenna is basically two full wave loops mounted at right angles fed 90 degrees out of phase to produce an omni-directional horizontally polarized pattern

Constructing a 2-meter Moxon antenna for MURS channels, this resource details the antenna's geometry and expected radiation pattern. The design, optimized for low SWR, high gain, and front-to-back ratio on the first three MURS channels, uses 1/8-inch bronze brazing rod for elements. Author John E. Davis provides specific geometric parameters (A, B, C, D dimensions) rounded to the nearest 16th of an inch, along with a link to the final _.nec_ file for further analysis. Performance results show the attic-mounted Moxon performs well on the 2-meter band, despite its MURS optimization, with measured SWR plots provided. NEC-2 modeling predicts over 6 dBi gain and 40 dBi front-to-back ratio in free space. The author compares its directional performance to a _J-pole_ antenna, demonstrating substantially better signal strength for a nearby repeater when the Moxon is pointed in its general direction, confirming its superior gain and directivity.

This resource details the construction of a Moxon rectangle antenna, a two-element wire beam, drawing inspiration from a _QST_ article by Allen Baker, KG4JJH, and a project group led by KD6WD. It outlines the use of _AC6LA_ software for critical measurements (A-E) to design the antenna for specific bands like 17 meters, emphasizing the simplicity of adjusting frequency and wire size. The guide covers material selection for spreaders, such as telescoping fiberglass fishing poles, and various hub constructions, including aluminum tubing and PVC joints, with accompanying images. The author shares practical insights from building multiple Moxons for 10, 15, 17, and 20 meters, noting consistent 1:1 SWR at design frequencies and broadbanded performance. It describes the feedpoint assembly using a 1:1 Yagi current balun and wire nuts for robust, adjustable connections. The resource also discusses element insulators made from Lucite strips and attachment methods to spreaders using plastic wire ties and duct tape, ensuring precise element spacing. Performance observations include significant signal improvements (4-5 S units) over quad loops and a unique "DX-Vane" effect where the suspended antenna self-aligns with the strongest DX signal. The author also recounts an unsuccessful attempt at a dual-band 17/20 meter Moxon, concluding that the Moxon is inherently a monoband antenna, supported by _EZNEC_ plots for a 17-meter design.

The W6NL Moxon Yagi is a high-efficiency two-element 40m Yagi that uses cross elements to provide both loading and Moxon coupling, addressing the challenge of deploying a directional antenna on the 40-meter band. This resource details the transformation of a _Cushcraft XM240_ Yagi into this Moxon configuration, replacing the original loading coil LCA sections with four new assemblies. The guide provides comprehensive instructions for building the boom and elements, including specific dimensions for new sections and tee loading elements, along with detailed drawings and a full parts list for the conversion. Performance data indicates the converted antenna achieves **10.73 dBi** gain at 7.050 MHz with 99.5% efficiency and a high front-to-back ratio. The VSWR bandwidth is over **300 kHz**, ensuring good performance across a significant portion of the 40m band. Construction involves reinforcing element sections, attaching tee loading elements with U-bolts, and implementing element guying using materials like _Phillystran_ to manage sag and maintain structural integrity.

The M0PLK multiband delta loop antenna project details the construction of a non-resonant, bidirectional antenna designed for 20-10m operation, requiring an external antenna tuner. The design utilizes two 5.65m aluminum tubes arranged at right angles, with 2x 2.80m antenna wires converging into a 2.30m ladder line, feeding a 1:4 balun. The resource provides a comprehensive parts list, including specific dimensions for aluminum tubes (25mm, 20mm, 16mm outer diameter), DX-Wire FS2, and custom 3D-printed components like a middle insulator, tube end caps, and ladder line spacers, with STL files provided. Construction steps cover base plate fabrication from a 300x300x4mm aluminum sheet, balun assembly, tube preparation with slits and threaded holes, and wire attachment with strain relief. Initial VSWR measurements are presented, indicating performance in line with expectations across the target bands. The author reports successful SSB test QSOs to the USA on 10, 12, 15, 17, and 20m immediately after completion. The project highlights the antenna's bidirectional pattern, noting the need for a lightweight, remote-controlled rotator to fully utilize its directional capabilities. Comparisons are drawn to the Cobweb antenna, with the M0PLK design cited for its reduced local QRM pickup. The article references external sources, including M0AWS's detailed report and PC modeling, along with other construction variants and commercial assembly instructions, providing a robust foundation for replication.

Such kind of omnidirectional antenna gives the possibility to be QRV with horizontal polarisation, as commonly used for the CW and SSB section of the 2m band. This actual design shows a 1.3:1 bandwidth of about 150kHz, centered to 144.200MHz.

Constructing a compact directional antenna for the 17-meter band, this resource details the build process for a Moxon rectangle, a two-element Yagi variant with folded-back elements. It covers the antenna's evolution from the _VK2ABQ beam_ and provides specific dimensions for a version built using fishing pole whips. The content includes a discussion of the antenna's radiation pattern, feedpoint impedance, and its inherent front-to-back ratio, which is often superior to a standard two-element Yagi. Practical considerations for element spacing and material choices are also addressed, alongside a visual representation of the antenna's physical layout. Performance data presented includes a comparison showing the Moxon rectangle's **2.5 dB gain** over a half-wave dipole and a front-to-back ratio of **20 dB**. The resource also touches upon the antenna's relatively wide bandwidth for a two-element beam and its suitability for portable operations due to its compact footprint. It offers insights into optimizing the design for specific operating conditions and discusses the advantages of its lower take-off angle compared to omnidirectional wire antennas, making it effective for DX contacts on the 17-meter band.

Constructing a directional antenna for the 6-meter band (50 MHz) can significantly improve signal strength and reduce QRM during local ragchews or **Field Day** operations. This project details the assembly of a Moxon rectangle antenna, known for its compact size and respectable gain, making it a practical choice for portable or fixed station use on the magic band. The design utilizes readily available materials such as 14 AWG copper wire for the radiating elements and PVC pipe for the frame, ensuring an inexpensive build. The article provides specific dimensions and construction steps, allowing radio amateurs to replicate the antenna with confidence. It emphasizes achieving a low **SWR** across a bandwidth exceeding 1 MHz, crucial for efficient power transfer from the transceiver. Performance characteristics include a reported 5.5 dBi gain and a front-to-back ratio of 20 dB, offering effective directivity. The project also highlights the antenna's suitability for Field Day, where quick deployment and reliable performance are paramount for maximizing contacts.

A 2m band Moxon antenna design is presented, centered at 145.2 MHz, with dimensions derived from Moxgen software. The design features a calculated 6 dBi gain, an 80-degree beamwidth, and an impressive 43 dB front-to-back ratio with minimal back lobes, concentrating RF energy in the forward direction. The antenna is balanced to 50 Ohms, facilitating direct feed. SWR sweep data from 144 MHz to 146 MHz demonstrates a near 1:1 SWR at the center frequency, maintaining healthy SWR values across the entire 2m amateur band. This performance is comparable to a 3-element Yagi, yet the Moxon offers advantages in compact size and ease of mast mounting, making it suitable for various operating environments.

A bi-directional vertical antenna with 4db gain over a dipole.

A 7 dB directional gain is reported for this portable VHF Yagi antenna design, which utilizes cut metal tape measure sections for its elements. The resource details the construction process for a 2-meter band antenna, emphasizing its ease of build and portability. It specifically mentions the design's suitability for radio direction finding (RDF), fox hunting, and communication with satellites and the International Space Station (ISS), highlighting its practical applications for amateur radio operators. The construction cost is estimated at under $20, with potential for even lower expense if salvaged materials like old tape measures and PVC pipes are used. The article references _Joe Leggio's_ (WB2HOL) original design, noting specific alterations made by the author. It also compares this design to other DIY Yagi antennas, including _FN64's_ 2-meter band and _manuka's_ 70-cm band tape measure Yagis, underscoring its unique combination of simplicity, portability, and effective performance with a 1:1 SWR achievable on the 2-meter band.

This simple project, based on the orginal CobWebb-Antenna model, is about an horizontally polarized, omi-directional antenna for the six meter band.

Build a directional antenna for the 1.2 GHz band, in 15 minutes

Antenna directivity and gain are fundamental concepts for any radio operator, as this article from _Electronics Notes_ explains. Real-world antenna designs, unlike theoretical isotropic radiators, do not radiate equally in all directions; their radiation patterns are often visualized using **polar diagrams**. These diagrams illustrate how power is focused in desired directions, crucial for both transmitting and receiving applications. The article clarifies how antenna performance is identical for both transmission and reception, a key principle for understanding antenna specifications. Operators often encounter terms like _beamwidth_, which defines the angle where power falls to half its maximum level, or -3dB. Understanding this parameter is vital for accurately orienting directional antennas like a Yagi. The discussion also differentiates between antenna gain expressed in dBd (decibels over a dipole) and dBi (decibels over an isotropic source), noting that dBi figures will always be **2.1 dB** higher than dBd. This distinction is critical when comparing antenna specifications to ensure an accurate assessment of performance. Furthermore, the article touches on the front-to-back ratio, another important metric for directional antennas, and the balance between maximizing forward gain and achieving an optimal front-to-back ratio.

The resource examines the operational characteristics and potential of Moxon Yagi antennas, drawing insights from Les Moxon's work and subsequent NEC modeling. It presents simulated current distributions and radiation patterns for a 40-meter Moxon, comparing its performance against a standard 2-element Yagi on the same band. Specific data points include forward gain, front-to-back (F/B) ratio, and feedpoint impedance, which are critical parameters for antenna design and optimization. Further analysis extends to a 20-meter Moxon, detailing its gain, F/B ratio, and SWR bandwidth across the band. The discussion highlights the Moxon's compact footprint and its ability to achieve respectable performance metrics, making it a viable option for hams with limited space. The content provides a technical assessment of the Moxon's advantages in terms of pattern purity and impedance stability compared to other compact directional arrays. The article also touches upon the practical considerations for constructing and deploying Moxon antennas, emphasizing the trade-offs between physical size and electrical performance. It includes graphical representations of antenna currents and radiation patterns, offering visual aids to understand the theoretical concepts discussed.

This Antenna project is a bit more complex than other omni antennas for satellite use, but it is much easier and cheaper than a standard tower mounted circular polarized azimuth and elevation rotating beam system.

Horizontal polarized omni directional 50MHz Antenna. This antenna is intented to use in a contest station as a second system beside the stacked yagi beam system. An omnidirectional systeem can be an advantage when it comes to short openings on wich the operator must react quickly.

Antenna Authority Inc. offers a wide assortment of directional, wideband antennas and other equipment specifically engineered for radio direction finding (DFing) and geolocation applications. Their product line includes _log periodic_, _cavity-backed spirals_, and _Yagi_ antennas, alongside covert antenna solutions for various operational requirements. The company emphasizes its expertise in designing and manufacturing specialized antennas for both overt and covert operations. Beyond standard offerings, Antenna Authority Inc. provides custom design services to meet specific client needs, focusing on tailored RF directional products. Their capabilities extend to developing antennas for vehicles and optimizing their operational performance in diverse scenarios. The firm is located at 3381 W. County Line Road, Douglasville, Ga. 30135-1145. Ferrel Bentley is associated with Antenna Authority Inc., which has been operating since at least 2005, as indicated by the copyright notice.

A 144 to 148 MHz J-pole antenna, optimized for base station use, is presented with detailed construction plans. This slim, omnidirectional, half-wave antenna is fed at the end through a quarter-wave shorted transmission line, drawing inspiration from the classic _Zepp antenna_. The design emphasizes achieving a 1:1 VSWR and good efficiency on the 2m band, noting that even a one-percent error in calculation can significantly impact performance. The article provides specific dimensions in inches for the radiator, quarter-wave section, and feed point, along with a parts list for construction from inexpensive materials, estimated at approximately **$10** total cost. The resource offers practical construction tips covering copper pipe selection, L and T joint variations, and detailed soldering instructions using a propane torch. It addresses feedline attachment, the critical role of a four-turn, _5-inch diameter_ choke to prevent coax radiation, and proper antenna fastening techniques, including grounding for lightning protection. The author explicitly advises against scaling the design for other bands due to potential efficiency loss and offers guidance on corrosion protection. The antenna design has been released into the public domain for private amateur use.

This antenna was conceived mainly for high-speed digital transmission via satellite. The antenna is made of two full waves loops , mounted at right angles to each other. Then coupled together, 90 degrees out of phase over a horizontal circular reflector. With this configuration the antenna is omni directional and circularly polarized.

This antenna is an omnidirectional and multiband and it is well suited for DX enthusiasts with limited space. Each of the parallel circuits (trap) behaves like an isolator on its resonant frequency.

The Homebase-10 is a wire halo antenna for 10m built with DIY store parts, effective despite its small size. Includes a dual-band version for 10m and 6m with gain around 0 to -2dBd, near omnidirectional pattern, and horizontal polarization. Overview based on a 2008 Practical Wireless article.

This article presents an innovative homebrew antenna design utilizing surplus ladder line as a receiving antenna for HF and MF bands. The Ladder Line Antenna (LLA) transforms standard 450-ohm ladder line into a directional, bidirectional, or omnidirectional antenna system through different termination methods. The design, which requires minimal space and height, achieves 6-10dB front-to-back ratio on 40-160m bands using a 33-foot length. This DIY wire antenna project offers an efficient, low-profile solution for amateur radio operators, featuring broadband operation without ground radials and easy installation below fence height.

The CobWebb antenna project is a compact, multiband HF solution ideal for amateur radio operators. Covering 14-28 MHz, it features a square dipole array with near-omnidirectional coverage and unity gain. This guide details a DIY approach, using a 1:4 current balun for impedance matching. Construction involves aluminum and fiberglass tubing, with optimized element tuning for SWR performance. Weather resistance improvements and resonance shift considerations are also discussed. Build your own CobWebb antenna for an efficient, space-saving HF experience.

An article describing basic concepts of antenna radiation, and in particular directional antennas like Yagi antennas or Quad antennas and how they determine the direction or signals.

The J Pole antenna is a good omnidirectional antenna that can be used for portable or fixed station usage. It does not need a ground, and neither complex feed systems. It can be homemade with simple material and in several ways.Article in Italian

A quarter wave vertical omni-directional antenna for 7 MHz. Formulas for dimensions in feet and meters are provided. Ideal radial angle is between 35° and 45°. Velocity factor (Vf) varies based on coax type.

Description and online calculator for Log Periodic Dipole Arrays LPDA are directional antennas featuring a relatively constant characteristics across a wide frequency range.

Make them simple then Make them work. The LAZY H antenna is a general type of antenna that is in the curtain array family. By placing two 1 wavelength dipoles in a plane that is at right angles to the direction of maximum radiation and keeping the proper in-phase current condition to each element, you can achieve a high gain bi-directional antenna.

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.