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Experiments on vertical antennas for HF bands.

Dipole antennas, vertical half-wave dipole antennas with impedence tranformes that can be used for portable operations. Some well worn antenna configurations are the easiest and loudest lash-ups you can try.

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.

The PAC-12 Antenna, a multi-band portable vertical, is meticulously detailed in this construction article by James Bennett, _KA5DVS_. The design emphasizes ease of homebrewing using readily available components from local hardware stores, including replaceable loading coils. It outlines the preparation of the 72-inch telescoping whip (originally from Radio Shack, with an alternate source now provided by _Pacific Antenna_), the construction of the loading coils from PVC risers, and the fabrication of the aluminum rod base sections. Specific instructions cover threading aluminum rod with a _1/4-20 threading die_ and assembling the feedpoint insulator with a BNC connector, along with recommendations for radial deployment. KA5DVS, an avid traveler and QRP enthusiast, developed the PAC-12 to address the bulkiness of random wire setups and the limitations of commercial portable antennas like the Outbacker or SuperAntennas MP1. His goal was a lightweight, packable antenna that disassembles into 12-inch sections, achieving an assembled length of approximately 8 feet. The design strategically places the loading coil away from the base for improved efficiency. The PAC-12 notably placed first in efficiency compared to a quarter-wavelength wire vertical at the HFPack antenna shootout during the Pacificon conference in October 2001, demonstrating its practical performance for field operations. Appendix C showcases various _NJQRP Club_ members' PAC-12 constructions, including a 20m beam made with multiple PAC-12 elements.

This article describes a simple yet effective multi-band vertical HF antenna design that performs exceptionally well across 80m to 10m bands. The antenna consists of a 13.4m wire mounted on a 12.4m Spiderpole, complemented by four 12m radials and a ground rod. Initially tuned with a manual LC circuit, it was later upgraded with a CG3000 remote auto ATU for convenient band switching. Despite antenna modeling software suggesting limited performance on higher frequencies, the system demonstrated excellent DX capabilities across all bands, outperforming more complex vertical antenna designs.

This article discusses suitable first HF antenna options for amateur radio operators with limited space. It recommends an Off-Center Fed (OCF) Dipole and a Vertical Dipole, detailing the installation processes, considerations for stealth and ease of setup, and the characteristics that make them ideal for newcomers. Safety warnings and maintenance tips are provided to ensure effective and secure operation.

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.

Learn how to easily improve your handheld VHF performance on the 2-meter band with the Flowerpot antenna. This simple DIY antenna made from coaxial cable requires minimal tools and materials, providing a big range upgrade compared to standard rubber-duck antennas. Discover how to build, tune, and optimize the Flowerpot antenna for excellent performance. Ideal for hams looking for lightweight, portable solutions for handhelds, mobile rigs, home stations, SOTA/POTA activations, and emergency communication.

This article describes the construction of a simple dual-band VHF/UHF end-fed vertical dipole antenna designed for local repeater access using an Icom IC-705 radio. Built from a single piece of RG58U coaxial cable, the antenna consists of a 460mm exposed inner conductor, 450mm of intact coax, and a 9-turn choke balun wound on a 27mm former. Mounted on a 10m Spiderpole, the antenna achieves excellent SWR readings (<1.2:1 on 2m, <1.5:1 on 70cm) and provides effective coverage of local repeaters with unexpected reach into distant locations.

This study details a reception comparison between vertical and horizontal active loop antennas, specifically two identical _Wellgood active loop antennas_, on various HF bands. The experiment, conducted in a densely populated QRM-prone area, monitored FT8 signals over a 24-hour period using two identical receivers. The methodology involved direct comparison of signal reception across the HF spectrum, aiming to identify performance differences based on antenna orientation. The results indicate that vertical loops demonstrated superior performance on higher bands (10m, 15m, 20m), while horizontal loops excelled on lower bands (30m, 40m, 160m), particularly for receiving long-distance (DX) signals. The horizontal loop's advantage on lower bands is attributed to potentially better low-angle performance and reduced sensitivity to man-made noise, yielding a **2-3 S-unit** improvement on 160m. The study provides practical insights for optimizing antenna placement in challenging urban environments, noting that the horizontal loop consistently showed a **10-15 dB** signal-to-noise ratio improvement on lower bands.

Experimenting and testing vertical antenna for HF bands on mobile operations.

Showcasing German engineering, ANjo Antennen develops and manufactures a diverse portfolio of amateur radio and commercial antenna products. Their offerings span a wide frequency range from 1.8 MHz to 3000 MHz, emphasizing electrical and mechanical precision for longevity. The company actively participates in events like FUNK.TAG Kassel, providing opportunities for direct engagement and order pickup. ANjo's product line includes high-performance **Yagi antennas** optimized for Tropo and EME, along with multi-stacked Quad antennas designed for contest operations, featuring wide horizontal and narrow vertical beamwidths. They also produce circularly polarized satellite antennas, some with switchable LHCP/RHCP, leveraging their commercial satellite antenna expertise. Beyond amateur applications, ANjo provides flexible, custom antenna solutions for commercial sectors such as BOS, EMC measurements, and telemetry. Their commitment to quality is evident in the Premium-Line antennas, which utilize **1.4301 (V2A) stainless steel** for mast clamps and connectors, ensuring durability and corrosion resistance. They also offer end-fed HF multiband wire antennas, known for their compact footprint and discreet installation.

A 5/8 λ antenna, often thought to be ideal for all frequencies, has unique characteristics that don't universally apply. First introduced for medium-wave radio, it works optimally at 225° antenna length over ideal ground, yielding high efficiency. However, at VHF and higher frequencies, it offers no advantage over other antennas due to real ground conditions and complex matching requirements. DIY calculators provide only rough estimates, useful as a starting point for simulations, not for precise builds.

This PDF document provides detailed information on the design, construction, and tuning of trapped vertical antennas with radials for ham radio operators. It covers the theory behind trapped antennas, practical considerations for installation, and tips for optimizing performance. Whether you are a beginner looking to build your first HF antenna or an experienced operator seeking to improve your station setup, this guide offers valuable insights and instructions. By understanding the principles outlined in this document, hams can enhance their operating experience and make the most of their radio communication capabilities.

For amateur radio operators engaging in portable operations like SOTA or POTA, rapid deployment of an effective antenna system is paramount. This video resource details the assembly process for the Buddipole multiband dipole antenna, showcasing its components and how they fit together. Rob, VK5SW, systematically presents the mast, coil arms, radiating elements, and the VersaTee hub, emphasizing the modular design that allows for quick configuration changes across various HF bands. The demonstration highlights the antenna's adaptability for different operating environments, from a ground-mounted vertical to a horizontal dipole. The video illustrates the ease with which the antenna can be packed and deployed, making it a practical choice for activations where setup time is limited. The Buddipole's design facilitates efficient band changes and tuning, crucial for maximizing QSO opportunities during field operations.

This page allows hams to design a vertical-plane delta-loop antenna for a single amateur HF band in different configurations. By choosing different feed-point positions, operators can observe variations in polarization properties, radiation patterns, and feed-point impedances. Users can generate radiation pattern plots, VSWR charts, antenna current diagrams, and Smith charts for their antennas over various ground types. Through adjusting the antenna's physical dimensions and refreshing the plots, hams can gain insights into the antenna's performance in the field. The page also discusses how elevation radiation patterns may change based on the antenna configuration and feed-point position.

This page provides information on designing a lightweight Moxon antenna for the upper HF bands and VHF. The Moxon antenna is a compact version of a 2-element Yagi with folded elements, offering good forward gain and a high front-to-back ratio. It is designed for a single band with a feed-point impedance close to 50 ohms. Hams can orient the antenna horizontally or vertically, with polarization following the configuration, affecting radiation patterns. The page allows users to generate radiation pattern plots, VSWR charts, antenna currents diagrams, and Smith charts for their antennas on different ground types, helping them understand antenna performance in the field.

Antenna patterns are all about interference. Presentation on wire antennas for HF bands. Dipoles, horizontal and vertical dipoles, effects of ground on radiation patterns, multi-band wires antennas. Knowing what you should expect from the radiation patterns for waves on your wires will help you choose what will work best for your needs. The principles of interference can lend insight into what to expect from a wire antenna.

A 10-meter half-wave vertical antenna, designed by Thomas 4L/G8BAG, offers a practical solution for hams with limited space and materials. This "flower pot" design utilizes common hardware store items such as 60mm plastic drain pipes and 75 Ohm coax cable, demonstrating that effective HF operation doesn't require specialized components. The author details the coax preparation, including stripping the outer sleeve and braid at specific measurements like **2510 mm** and 2450 mm, and integrating it into the pipe structure. The construction emphasizes simplicity and low cost, providing an accessible path to getting on the air on the 10m band, especially when a horizontal beam is not feasible. The article notes an SWR of _1.5:1_ with 75 Ohm coax, managed by an MFJ 258 for impedance matching. This temporary solution proved robust, withstanding various weather conditions and achieving contacts across continents, including W, VK, BG, G, JA, and VR2, using 100W SSB from Georgia.

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.

The Butternut HF2V, originally a two-band vertical antenna for 80m and 40m, was enhanced by the user to include 30m and 20m bands for better digimode DX work during the solar minimum. The additions used components adapted from the HF6V and innovative methods for the 20m addition, either through a parallel vertical element or a lower-mounted independent element, minimizing band interaction. This modified four-band antenna now supports high power across popular HF bands using a single feedpoint.

Constructing a double bazooka antenna for the UHF band, specifically tuned for 435 MHz, involves a straightforward process detailed with step-by-step imagery. The design leverages readily available _RG213 coaxial cable_, cut to precise lengths derived from formulas: 140.208 / F (MHz) for the radiating element and 99.06 / F (MHz) for the coaxial section. This approach yields a highly effective vertical polarization antenna, suitable for local ragchewing or repeater access. My own field experience with similar coaxial designs confirms their robustness and ease of deployment. The article emphasizes critical steps like short-circuiting cable extremities, interrupting the braid at the center, and securing an insulating support. It also covers preparing the definitive mounting with a quality feedline, noting that RG58 is acceptable for temporary use but better options exist for permanent installations. Weatherproofing is crucial for longevity, achieved through PVC electrician's tube, glue, and heat-shrink tubing. The final assembly is designed for mounting on a small aluminum mast, with the feedline routed internally. The reported SWR measurement is very satisfactory, showing approximately **+/- 3%** HF return, indicating excellent impedance matching at the target frequency.

The resource details the construction of a J-pole vertical antenna specifically engineered for motorcycle mounting, addressing the common issue of interference with top cases. It outlines the fabrication process, beginning with an aluminum angle bracket for secure attachment to the lateral support, followed by the creation of the antenna's base from an 8mm threaded rod bent into a U-shape, approximately **40mm** wide. The article specifies the precise method for coaxial cable connections using eyelets and 3mm screws, ensuring robust contact. Further construction steps involve fitting a 10mm aluminum tube onto the threaded rod, with a screw securing the radiating element and establishing core contact. The design prioritizes mechanical stability against vehicle vibrations over fine-tuning SWR with sliding collars. Initial testing yielded a _SWR_ of **1.2** across a significant portion of the band, with improvements noted by optimizing the coaxial braid contact point near the support bracket. The document provides practical insights into material selection and assembly, emphasizing durability for mobile operation. It concludes with aesthetic options, allowing the builder to paint the antenna or retain its natural aluminum finish, making it a functional and adaptable solution for UHF motorcycle communications.

This page offers a tool for hams to design vertical antennas for portable use on different HF/VHF/UHF bands. Vertical antennas provide omni-directional transmission and reception, making them ideal for DX contacts. By adjusting the antenna's dimensions and viewing radiation patterns and VSWR charts, hams can optimize performance in various terrains. The tool also accounts for the impact of sloping ground on elevation radiation patterns. Perfect for hams looking to enhance their portable radio setups and improve long-distance communication.

The 2m 7 element Yagi antenna is a perfect beam antenna with 11dB gain and a front-to-back ratio of 20-25 dB. It has seven elements and requires a matching network built of 3/8" aluminum tubing and RG-8 cable. The gamma tube is adjusted to provide the best fit, and the gamma-driven element feeding clamp is tightened. If the beam is vertical, a non-conducting mast is utilized to prevent detuning and skewing of the radiation pattern. For optimal VHF operating, the antenna is installed at a height of 30 feet or higher.

VE1ZAC's analysis details the performance of **MFJ927** and **SGC239** autotuners with portable HF vertical antennas, specifically comparing 31 ft and 43 ft configurations. The resource originated from challenges encountered during a Maritime QSO Party roving operation, necessitating a lightweight and easily deployable antenna system. Target bands for the contest included 80, 40, 20, 15, and 10 meters, with a maximum power handling of 100 W CW. The author utilized a 30-foot carbon fiber push-up pole to support a vertical wire element, noting its 2 lb weight and reliability. EZNEC modeling was employed to predict performance, showing favorable results for a 30-foot vertical with elevated radials, particularly on 40 and 20 meters. Feedpoint impedance measurements, taken with an AIM4170C, are presented for various HF bands, both with and without a 41-foot RG6 stub designed to reduce reactance on 80 and 20 meters. The stub significantly improved matching on these bands, easing the tuner's workload. Operational tests revealed issues with the MFJ927's reliability during contest setup, leading to reliance on the K3's internal tuner. The SGC239, tested post-contest, performed flawlessly. A detailed side-by-side comparison covers mechanical aspects, connection options, power bias, impedance range, board quality, and documentation. Modifications to the MFJ927, including a new aluminum case, white paint for heat reduction, and upgraded impedance-measuring resistors, are also described.

This PDF document discusses the setup and operation of UHF vertical dipole phased stack antennas for hams. It covers the advantages, principles, and practical aspects of using this type of antenna configuration. The document is a useful resource for amateur radio operators looking to improve their UHF station setup with phased array antennas.

The XW4DX DXpedition website documents the amateur radio operation from Laos, a country ranked #98 on Clublog's Most Wanted list. This resource provides insights into the planning and execution of a significant DXpedition, including antenna choices like _Hexbeams_ at 14m, a 4-square for 40m, and a top-loaded vertical for 160m. The team, comprising operators such as _F4BKV Vincent_ and _F2DX Patrick_, focused on challenging paths, particularly towards the North American East Coast, where Laos is #41 most wanted. Operational constraints included prohibitions on 6m, 30m, 60m, and 80m bands within Laos, necessitating a focus on other HF frequencies, especially 160m and 40m. The expedition utilized up to five stations simultaneously, with equipment transportation being a major logistical challenge, partially mitigated by direct shipments from _Spiderbeam_ and donor support. The expedition ran from November 16th to 27th, 2023, with the complete XW4DX log uploaded to LoTW by December 23rd, 2023. This site serves as a historical record of their efforts to put Laos on the air for DXers worldwide.