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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 160 meter Delta Loop antenna is made of Hard drawn copper wire AWG 10, the two upper side are 148.5 foot each base wire is 240.9 foot, the feed point at 30.69 foot to one corner, feed with 450 Homs balanced line to an antenna tuner on the ground, then with 50 homs coax to the shack.

Examines Teledyne Cable Solutions' offerings, focusing on their engineered solutions for demanding cable applications. The resource details their capabilities in designing and manufacturing _multi-core cable_ and ruggedized assemblies, emphasizing their integrated approach within Teledyne Marine. It covers the technical aspects of their products, which are tailored to specific operational environments and performance requirements, ensuring reliability in challenging situations. The content highlights the practical application of their cable solutions across various industries, including those requiring robust interconnectivity for remote sensing or communication systems. It implicitly suggests how these specialized cables, designed for high performance and durability, could benefit amateur radio operators seeking reliable feedlines or control cables in extreme weather or portable operations, potentially offering superior signal integrity and mechanical strength compared to standard offerings. The company's focus on custom solutions distinguishes its approach.

Steve Nichols, G0KYA, presents a practical examination of ground systems for vertical antennas, drawing heavily on the empirical research of Rudy Severns, N6LF. He explains that a robust radial field is crucial for ground-dependent verticals, effectively replacing the antenna's "missing half" and mitigating severe RF absorption in lossy soil. Nichols clarifies that surface radials do not strictly require a quarter-wavelength; instead, deploying a minimum of 16 to 32 shorter wires often yields superior results compared to fewer, longer ones. The presentation also addresses the common SWR paradox: a poor ground might show a perfect 1:1 match, but adding radials, while potentially raising the SWR to around 1.4:1, significantly improves true radiation efficiency. Nichols defines counterpoises as elevated wire networks that substitute for earth connections, offering solutions for limited-space installations, such as the **Folded Counterpoise (FCP)** for 160 meters. This resource provides actionable engineering data for optimizing vertical antenna performance.

LZ1AQ describes a versatile QRP antenna tuner that switches between Pi and Tee configurations with a single toggle. Using two variable capacitors and a seven-switch stepped inductor providing 128 increments (0.16 to 18.7 uH), this compact design handles 3.5 to 28 MHz with excellent matching range. The Pi mode works best for certain impedances while Tee mode proves more universal, matching loads the Pi cannot. Built in a plastic enclosure using salvaged radio capacitors, the tuner operates reliably up to 100 watts with proper antennas, though it's optimized for QRP service with random wires.

Article about shields, Litz wire, braid, and skin depth. It is still being expanded.

TelExpress provides a wide array of RF and data connectivity products, including various coaxial cables like LMR-series equivalents, fiber optic cables, and Ethernet solutions. Their inventory supports diverse amateur radio and telecommunications requirements, from antenna feedlines to network infrastructure. The site emphasizes bulk cable availability and custom assembly services, catering to both individual hams and larger installations. Key offerings include _low-loss coax_ for HF and VHF/UHF applications, along with a comprehensive selection of RF connectors. They also supply patch panels, Ethernet cables (Cat5e/Cat6), and general wireless and telecom hardware. Customers can find components for building robust station infrastructure, ensuring signal integrity across various frequency bands. The platform facilitates procurement of essential parts for new builds or upgrades, supporting reliable RF system performance.

You can bend the wires in a half-wave dipole so that it takes up less space, with minimal loss of efficiency.It is advisable to get the ends of the antenna as high as possible, especially if children and animals are kept in the area around the antenna, as there are very high tensions on the ends of the antenna during transmission! In Norwegian

A premier club that brings out the very best in Amateur Radio around the Sheffield area

This blog post details the construction and usage of a 4:1 current balun, using two FT240-31 ferrite cores and 12 bifilar turns. It clarifies common misconceptions about using 4:1 baluns with G5RV antennas and ladder-line to coaxial cable connections. M0PZT emphasizes the importance of proper measurements and the limitations of internal baluns in manual antenna tuners. Detailed instructions and considerations for winding and deploying the balun are provided, along with advice on choosing suitable cores and wire for various power levels and frequency ranges.

An article about the Beverage antennas, super long wire receiving antennas thar are unidirectional and have a very low noise that makes this antenna excellent for low band dxing. By Thomas R. Sundstrom W2XQ, 73, June 1981, 73 Magazine

The Massie Wireless System station, PJ, built in 1907, is the oldest surviving working wireless station in the world

Founded in 1958, as the Wolverton & District Radio Club, largely by members of the Diplomatic Wireless Service at Hanslope Park, MKARS now has over 120 members

Building an End-Fed Half-Wave (EFHW) antenna from a kit, as detailed by Frank Bontenbal, PA2DKW, with process photos by Bob Inderbitzen, NQ1R, offers a practical approach for hams. This specific kit, a collaboration between ARRL and HF Kits, targets 10, 15, 20, and 40 meters, making it a versatile option for HF operations. Unlike a center-fed dipole, the EFHW is a half-wavelength antenna fed at one end, which simplifies deployment, particularly for portable use. The construction guide meticulously outlines the assembly of the 49:1 impedance matching network, crucial for transforming the antenna's high impedance (around 2,500 Ohms) to a transceiver-friendly 50 Ohms. Steps include preparing the enclosure by drilling holes for the coaxial connector and antenna connections, followed by the precise winding of enameled copper wire onto a toroid to create the transformer. The guide emphasizes careful insulation removal and soldering for reliable connections. Final assembly involves integrating a 100 pF capacitor for higher band compensation, soldering the transformer's primary and secondary sides, and conducting SWR tests with a 2K7 resistor or a half-wavelength wire. The document also provides examples of wire lengths for different bands, such as 16 feet for 10 meters or 66 feet for 40 meters, demonstrating the transformer's adaptability for various half-wavelength configurations.

Pro-cell Co., Ltd was established in 1995 to produce and develop wireless components. In the beginning stage, we concentrated on producing GSM antennas, now produce Commercial- RFID, GSM UMTS GPRS LTE WLAN Wi-Fi Wi-Max, PMR & Tetra antennas

The title may seem a strange question. Still, it is often said that the part where the current is largest, radiates most. And from that a rule of thumb follows, saying that if you don't have enough space to hang a complete half-wave wire dipole then try to make the central part hang as freely as possible.

This article describes the construction of a three-band vertical antenna for the WARC bands (10, 18, and 24.9 MHz). Unlike a previous design using thin wire requiring a complex matching device, this version uses a telescopic set of pipes, reducing reactances and simplifying the matching device to two coils and two capacitors. The article provides details on the antenna model, the matching device circuit, and tuning methods, including the use of frameless coils and variable capacitors. With proper tuning, the antenna achieves a VSWR not exceeding 1.3 across all bands, demonstrating a practical and efficient design for amateur radio enthusiasts.

HF Antennas is a division of Comsystems Solutions we manufacture wire broadband antennas and different type.

This will show you how to add a RF power amplifier to your Proxim Symphony for under $50. The cost is reduced by using the existing components on the Symphony, such as the PIN diode switch, and just inserting a higher power final amplifier. Increase the RF output power of your wireless network card to 1 Watt.

Article about the essentials of radio signal path loss, its causes and prediction, and its use in radio coverage and wireless survey tools

Experimentin wire antennas on top band using several type of aerials. This includes a 40 to 160 meters EndFed Half Wave kite antennas and 160m/80m loaded vertical antenna.

The author reflects on expanding their antenna for 80m coverage during lockdown. They extend the End Fed Half Wave (EFHW) using a Spiderbeam pole and "cheating" by dog-legging across their garden. Despite challenges, they achieve coverage for multiple bands with minimal cost. Practical Wireless features EFHW antennas, including a pre-made 20m EFHW extended for 40m.

The antenna I built was inspired by a portable delta loop designed by Doug DeMaw, W1FB. Given that I constrained myself to a 50-foot roll of speak wire, I scaled my antenna for the 20M band. Using the formula, 1005 divided by the frequency in megahertz, I calculated a total length of 71 feet (21.6 meters) for the center of the 20M band.

This page presents an online calculator tool for determining the dimensions of various HF wire antennas operating between 1.8-30 MHz. Users input their desired resonant frequency to obtain precise measurements for four popular antenna types: standard flat-top dipole, inverted Vee, quad loop, and equilateral delta loop. The calculator provides comprehensive measurements including leg lengths, minimum heights, horizontal spreads, and feedpoint distances. Accompanying the calculator are detailed technical explanations, construction notes, and installation guidelines for each antenna type, making it a practical resource for amateur radio operators building their own antennas.

In the quest for an ideal field portable antenna, the author recounts experiments involving various wire configurations. While a previous candidate, a 41ft random wire, proved effective but lacked stealth, the search led to a surprising rediscovery of a design previously rejected—the Rybakov Antenna. With a focus on simplicity, rapid deployment, and multiband capability, the author explores the versatility of a 26ft Rybakov, avoiding the halfwave trap. The article delves into the antenna's performance and its potential as a discreet, resonant solution for field operations, addressing the challenges encountered during a POTA activation. Additionally, the Unun/Balun design used in conjunction with the Rybakov Antenna is discussed, providing insights into achieving a balanced system.

This stacking offers a well known simple phasing technique. All elements can be fed in parallel by open wires provided that they are fed in phase. This can be achieved by twisting the open wire phasing-lines at 180 degrees.

A dual band X-frame wire antenna made using 4 turns for response down to 3 MHz or so, and 2 turns (switched) for response up to around 18 MHz. The loop configurations are tuned using common eBay 365 pF tuning caps.

This air-core solenoid style RF inductor calculator calculates the inductance, wire size, number of turns, and other parameters for an air-core solenoid inductor used in radio frequency (RF) circuits, based on user input of frequency, desired inductance value, and physical dimensions.

Free windows application for RF Microwave and Wireless applications. AppCAD is useful for the design and analysis of many circuits, signals, and systems using products from discrete transistors and diodes to Silicon and GaAs integrated circuits. AppCad is a unique suite of RF design tools and computerized Application Notes to make your wireless design job faster and easier

This blog chronicles the development of an 80-meter vertical antenna for amateur radio operation. The author constructs a top-loaded vertical using fiberglass poles, achieving significant performance improvements over their previous end-fed wire antenna. Comparative testing using the Reverse Beacon Network and on-air contacts demonstrates 8-10 dB gain on the east coast. The project evolved to include 40-meter capability through a modified design featuring a four-wire vertical cage, loading coil, and strategic guying system. Despite challenges with signal wobble during windy conditions, the vertical consistently outperforms the end-fed wire, particularly for reaching distant stations during nighttime propagation.

Build A Shortened 40 Meter Vertical antenna For POTA / SOTA Activations. A project for a portable wire antenna for 40 meters band suitable for POTA or SOTA operations.

Operating within the low-frequency spectrum, transformers serve critical roles in antenna systems, particularly for 160m applications. The resource details the construction and performance of 1:1 transformers built on BN-73-202 cores, emphasizing their use as hybrid combiners or phase inverters for RX antenna arrays. Measurements reveal that these transformers exhibit minimal losses, around 0.12 dB at 1.8 MHz, with variations based on wire type and number of turns. The analysis includes comparative data on transformer performance, highlighting the impact of different winding techniques on frequency response. Notably, the use of coaxial cable for winding improves bandwidth while maintaining low-frequency efficiency. The resource also discusses braid breaker transformers, which minimize inter-winding capacitance, achieving low losses around 0.21 dB at 1.8 MHz. These insights are crucial for optimizing low-band antenna systems, allowing operators to make informed decisions regarding transformer design and implementation.

An Inverted-L with its long leg sloping to the ground. It will still work very good, even if the horizontal wire has to be sloped diagonally to the ground, as long as you have enough horizontal space to keep it at about a 45 degree angle or more from the pole.

How to Design and Build a Field Expedient End-Fed Half-Wave Antenna for 20m, 40m and 80m. This Shorty 80m EFHW comprises a 49:1 autotransformer (to match the very high impedance at the end of a half-wave wire), a half-wavelength wire for 40m (also a quarter-wavelength for 80m), a loading coil and a short tail wire. The coil and the short tail wire (about 6 feet) make up the other quarter wave on 80m.

Dipole for 40m band. It is a simple linear loaded dipole feeded with 450-Ohm openwire feedline. Designed it for resonance at 7.050 MHz, can be tuned on 30m and 80m bands with an external antenna tuner. Build with simple electrical copper wire (2.5 mmq/13 awg) and two fishing poles with size of about 7 m/23 ft.

This article explores budget-friendly methods for launching wire antennas into trees, comparing common options like slingshots and professional arborist tools. The author introduces a simple and cost-effective DIY approach using latex balloons, sand, and readily available materials for efficient antenna deployment in the field

In this article the author feature the various types of beam antenna that can ben builw using wires, like moxon, spieder and hex beam, delta loops, bird yagi

About LoRa, wireless communication technology designed to transmit data over long distances. LoRa provides a means for wireless data transmission over long distances with low power consumption. Practical applications of LoRa in amateur radio

This page offers an online antenna designer to calculate the dimensions for a collinear dipole antenna at a specified frequency. The collinear dipole antenna is constructed with multiple 1/2 wavelength sections separated by a 1/4 wave phasing stub in the form of a coil. It requires a ground-plane to operate and can be used for both receiving and transmitting purposes. The antenna can be made from common copper wire, with thicker wire providing a wider bandwidth. The calculations are based on radio waves traveling at the speed of light. Ideal for ham radio operators looking to build their own antenna for improved reception and transmission.

This document details the construction of a multi-band end-fed antenna, suitable for situations with limited space for larger antennas. The design utilizes a 1:49 to 1:60 impedance transformer to match a half-wave wire antenna fed at one end. Compared to a traditional dipole, this antenna resembles a highly unbalanced Windom antenna with one very long leg and a virtual short leg. The design eliminates the need for radials but relies on the coax cable shield for grounding. The document recommends using at least 10 meters of coax and installing a common mode filter at the entry point to the shack for improved performance.

The Greater New York Vintage Wireless Association is the number one club serving the collector of antique and vintage radios, TVs, and electronic equipment in the New York City Long Island area.

Integrating a **160-meter vertical wire antenna** with an existing 80-meter Yagi system presents unique challenges for Top Band operation. This project outlines the author's experiences with seasonal antenna removal and reinstallation, a necessary task for agricultural land use. It details specific issues encountered, such as incorrect coil sizing and relay configuration problems, providing practical insights into common pitfalls. The article describes the iterative tuning process, comparing **NEC model** predictions with actual on-air performance. It emphasizes the importance of precise measurements and adjustments to achieve optimal resonance and impedance matching. The author shares lessons learned from troubleshooting, including the impact of ground system integrity and feedline considerations. Concluding with an antenna checkup, the resource addresses long-term maintenance aspects, including galvanic corrosion prevention and general upkeep for reliable operation.

Coil64 (Coil32) is a versatile tool for calculating single-layer inductance coils used in various electronics, such as matching circuits and amplifiers. The online calculator enables users to estimate the number of turns, winding dimensions, and select the appropriate wire type for home-brewed RF inductors. It employs Bob Weaver's equation, factoring in wire corrections, and allows for the calculation of Q-factor and self-capacitance. Coil64 is compatible across multiple platforms, including Windows, Linux, Mac-OS, and Android.

Presents a detailed construction guide for a 9 dB, 70cm collinear antenna, utilizing readily available _RG58/U_ coaxial cable and PVC pipe for housing. The resource outlines the critical calculations for ½ wavelength sections at 444 MHz, incorporating the coaxial cable's velocity factor of 0.66, which yields a section length of 223 millimeters. It specifies the preparation and soldering of eight such half-wavelength sections, each cut to 231mm to allow for trimming, forming the core of the array. Further instructions detail the integration of a ¼ wave element (169mm #16 solid wire) at the top and a ¼ wave aluminum tube (160mm, 5/16 inch) at the bottom, crimped to the feed point's braid. The guide also addresses RF common mode current suppression by suggesting the use of _FT50-43_ toroids on the feedline. Final assembly steps cover mounting the antenna within ¾" PVC pipe using a wooden dowel, waterproofing connections, and initial SWR checks. The article also discusses scaling the design for different element counts and other VHF/UHF bands.

A Home made antenna tuner for QRP transceivers. This small tuner is the ideal for portable operations with random length wires or whenever you have not a resonant antenna.

The U01 emergency communications antenna is a versatile, multiband antenna designed for 80/60/40/20/17/15/10m bands, known for its reliability and compact size. It features a broadband transformer wound on various core options like FT82-43, FT114-43, or FT140-43, with the latter capable of handling up to 100W. The antenna incorporates a PCB with options for SMA and BNC connectors, and a weather-proofed design for durability. The lightweight construction, using materials like DX Wire UL and Polyester rope, makes it highly portable. The antenna's design has been tested and proven within the DARC Chapter U01, with multiple build options and detailed documentation available for DIY enthusiasts.

The author explores a portable version of the half-square antenna, typically a single-band structure. Using a 9:1 unun for versatility, they describe construction with speaker wire, deployment using collapsible poles, and field tests, achieving successful contacts on multiple bands. The article suggests efficient matching methods and concludes with the antenna's integration into the author's portable options.

An Excel sheet calculator for the T2FD wire antenna. The sheet has been proved to work either on LibreOffice and Apple Numbers. Just input the resonating frequency to get the proper size and dimensions.

A primer on Ham Mesh networks, hams using our radio privileges to operate a private, self-contained wireless computer network

WB8LZR details the construction and initial field results of a multi-band vertical wire antenna, designed to complement his existing horizontal loop for improved DX on 80 meters. The antenna utilizes a 67-foot vertical wire, configured as a quarter-wave radiator on 80m, and employs a 1:1 current balun for RF isolation on 80m, 30m, and 17m. For bands like 40m, 20m, and 10m, where the wire acts as a half-wave or full-wave radiator, an additional impedance transforming _unun_ is integrated to manage the significantly higher feedpoint impedance and voltage. The author notes the vertical's performance as a receiving antenna, observing reduced noise compared to his main horizontal loop, particularly on 80m, and even hearing some long-path signals the loop missed. Initial QRP contacts, including a **1-watt** QSO with a _VP2 station_ on 30m, demonstrate its transmit capability. While the radial system is currently rudimentary, the project outlines practical considerations for multi-band vertical deployment and impedance matching.