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The W5GI Mystery Antenna is a versatile multi-band wire antenna designed for amateur radio operators. It covers frequencies from 80 meters to 6 meters, making it suitable for a wide range of operating conditions. The antenna features a low feed point impedance, allowing for easy matching with most radios, whether or not an antenna tuner is used. Its construction is straightforward, requiring only two vertical supports approximately 130 feet apart, making it ideal for hams without towers. Users have reported excellent performance, particularly on the 20-meter band, where it outperforms similar designs like the G5RV. This antenna is unique in its design, incorporating three half waves in-phase on 20 meters, resulting in a six-lobe radiation pattern. Despite its effective performance, the antenna is challenging to model, which adds to its mystique. The W5GI Mystery Antenna has gained popularity among amateur radio enthusiasts worldwide, with many users praising its ease of construction and effectiveness. Whether you're a beginner or an experienced operator, this antenna offers a fun and rewarding project that can enhance your HF capabilities.

Build a space efficient trapped dipole antenna for 40-80-160 meter bands using RG-58 and PVC pipe. The document provides a brief guide on building a compact dipole antenna appropriate for the 40, 80, and 160-meter amateur radio bands. It explains the materials, building processes, and tuning methods required to provide best performance while preserving space. The paper also discusses theoretical elements of dipole antennas, such as impedance matching and feedline selection.

Demonstrates the construction of a **multi-band HF mobile antenna** utilizing a modified CB whip antenna base. The resource details the process of stripping a commercial CB whip, winding a new helical coil with 0.7mm insulated copper wire, and identifying tapping points for various HF bands. It emphasizes the importance of a rugged, slim design for mobile operation, discussing mechanical length, power handling (up to 200 watts), and coil diameter considerations. The article includes a graphic illustrating the antenna's operational principle, where sections of the helical coil are shorted from bottom to top to maintain efficiency and high Q. The resource presents a practical approach to achieving **band switching** without an external tuner, by manually adjusting tapping points on the coil. It provides a table with reference lengths in centimeters from the feedpoint for 7 MHz (40m) through 28.7 MHz (10m), including WARC bands. The author details mounting techniques, suggesting a Diamond bracket for secure attachment to a vehicle trunk, and stresses the critical role of proper grounding for optimal performance. The design allows for operation on 75m and 80m bands by adding a 110mm steel whip.

A modified 20 meter double zepp wire Operating Bands: 40 thru 10 meters (with tuner), basic construction and performance information.

A 10-20 meters coverage delta loop antenna. After relocating, DL2HCB designed a multiband loop antenna to cover 10-20m with an open-wire feed for impedance matching and compact installation. Inspired by the mini-X-Q design, a modified 10m delta-loop was built, enhanced with a 1/4 wave shorted stub for 28 MHz using 450-ohm ladder line. The antenna delivers east-west broadside radiation and performs as a closed loop on other bands. Operational tests yielded strong European signals and successful DX contacts, including a 20m QRP QSO with FY/DJ0PJ.

The G5RV antenna, with an overall length of **31.10m (102ft)**, functions as a 3/2-wave on 20 meters when installed horizontally at 12m (39ft), exhibiting a resonant frequency of 14.150MHz and an approximate resistance of 80 ohms. Its 10.36m (34ft) stub line, designed as a 1/2-wave on 14.150MHz with a 0.97 velocity coefficient, acts as an impedance transformer across other bands, aiming for multiband operation without traps. On 20m and higher frequencies, the G5RV demonstrates improved gain compared to a standard dipole, attributed to the _collinear effect_ from multiple 1/2-waves along the wire. The original design sought a multiband solution for limited spaces, often requiring an Antenna Tuning Unit (ATU) for effective operation across bands like 80, 40, 30, and 20m, particularly with modern solid-state PAs. Variants, such as the F8CI modification, incorporate a 1/4 current balun at the stub line's base for symmetrical-to-asymmetrical transition, known as a _remote balun_. Proper flat-top or inverted-V installation is critical for maintaining symmetry and collinear gain, with inverted-V apex angles below 120° progressively diminishing higher-band performance.

This resource provides comprehensive instructions for constructing a 2 element quad antenna specifically designed for the 10, 12, and 15 meter bands. The antenna features a diamond configuration, which offers improved gain compared to a square configuration. The author shares insights into the materials used, including a square-aluminum boom and bamboo poles, along with construction techniques that ensure durability and optimal performance. This project is ideal for amateur radio enthusiasts looking to create their own antennas at home. In addition to construction details, the author discusses the antenna's performance, noting its effectiveness even at a height of 8 meters. The quad antenna reportedly performs comparably to a 3 element yagi, with excellent SWR readings and strong signal reports from European stations. This project is suitable for beginners and offers a cost-effective solution for those interested in enhancing their amateur radio setup with a homemade antenna.

Portable wire antenna for 40 and 80 meter made with a RF Chocke. Can be adapted to work on 160 meters by adding additional 6.9 meters wire at its end.

Dissects the internal components of the popular _Antron 99_ vertical antenna, revealing its unique design elements. The analysis details the construction of the coaxial phasing sections, which contribute to its multi-band performance across 10, 12, 15, and 17 meters. Observations include the use of fiberglass tubing for weather protection and the specific arrangement of conductors within the antenna's structure. The examination highlights the antenna's reliance on a series of coaxial stubs to achieve resonance on multiple HF bands without external tuning. This internal architecture provides insights into how the _Antron 99_ manages impedance matching and radiation patterns for effective DX operation. Further details cover the antenna's base mounting and overall physical dimensions.

The page provides a project for an indoor wire antenna for the 7 MHz band, based on a design by F6CYV. It aims to help amateur radio operators lacking space to set up an antenna for 40 meters. The author shares their experience using the antenna inside an apartment, noting good reception of European signals and contacts with over 150 countries. The project details the materials and dimensions needed for the antenna, along with tips for optimal performance.

Demonstrates the construction of **magnetic loop antennas**, detailing both multi-turn and single-turn designs. It covers a 30-inch diameter multi-turn loop for 80 meters, based on a February 1996 QST article, and an octagon single-turn loop made from 15mm copper tube with a 4.8-meter circumference, operating from 7 MHz to 14 MHz. The document also presents a smaller 800mm diameter loop for 14 MHz to 28 MHz, emphasizing the importance of high-voltage tuning capacitors. Covers the design and construction of custom **butterfly capacitors** and piston capacitors, including a split stator capacitor with 140 pF capacitance and a 6000 Volt rating, and a butterfly capacitor with 5-65 pF and 7200 Volt rating. It explains why butterfly capacitors are preferred over split stator types for high power applications due to lower losses and direct series connection of rotors, reducing resistive losses from wiper contacts. Material recommendations include clear PVC for plates and brass or stainless steel for non-magnetic hardware. Addresses practical considerations such as feeding the loop with a shielded 1/5 Faraday loop made from RG213 or RG8 coax, achieving VSWR 1.1 across bands, and optimizing its placement 180° from the capacitor. It also discusses mechanical joint resistance, dissimilar metal oxidation prevention using Vaseline, and a simple method for determining radiation angle with a TL-light tube. The guide includes diagrams for rotor, stator, and end plate construction.

Presents _Henry Radio Inc._ as a manufacturer of solid-state RF power amplifiers, detailing their capabilities across HF, VHF, and UHF bands. The company designs and builds custom amplifiers tailored for various applications, including amateur radio, commercial broadcasting, military, scientific, and industrial uses. These amplifiers are manufactured in the USA, emphasizing domestic production. Beyond amplifier manufacturing, the resource highlights Henry Radio's role as a distributor for _Bird RF Test Equipment_, including wattmeters, dummy loads, and attenuators. It also mentions _Tohtsu Coaxial Relays_ and a range of miscellaneous amplifier parts and electronic accessories, providing a broader scope of communication equipment offerings. Additionally, the site describes a trunking two-way radio system operating on the 450-476 MHz band, covering significant portions of Los Angeles and Orange County. This service caters to professional dispatch needs for ambulances, taxis, and other commercial entities, requiring no long-term contracts.

Base station and repeater antennas, mobile antennas, ,multi-band HF antennas , handheld transceivers, receiving and scanner antennas, power meters, swr meters, power supplies, coaxial switches

For radio amateurs considering homebrew antenna projects, this resource details several designs from WE6W, an experienced operator. It covers the construction and characteristics of a _160 Meter QRP Loop Antenna_ optimized for high voltage, along with standard and folded variations of the double bazooka antenna. The site also presents a unique Field Day antenna design and instructions for building a Sterba Curtain, a directional array known for its gain. Each design includes practical insights from the author's building experience. The author provides comparative data, such as the performance of a standard bazooka against a traditional dipole, offering real-world context for antenna selection. The Sterba Curtain section includes notes on its beamwidth and gain, crucial parameters for directional operation. These designs are suitable for hams looking to experiment with cost-effective, high-performance antennas for various bands and operating scenarios, from QRP on 160m to directional DXing with a Sterba Curtain, which can offer significant forward gain, often exceeding **10 dB**.

The Pfeiffer Maltese Quad Antenna System presents a unique approach to traditional quad antennas by utilizing a linear loading technique. This method effectively reduces the overall size of the antenna while maintaining its performance capabilities. Designed by Andrew Pfeiffer, the antenna's configuration resembles a Maltese cross, which not only enhances its structural integrity but also allows it to withstand challenging environmental conditions. This system is adaptable, offering various configurations from a 4-spreader Maltese Quad to a 16-spreader Maltese Quadruple-Cross, making it suitable for operators looking to optimize their setup without sacrificing efficiency. This antenna system is particularly versatile, covering multiple bands including 40, 20, 17, 12, and 10 meters. The design focuses on minimizing the physical footprint while ensuring effective signal transmission and reception. Amateur radio operators can benefit from the detailed plans available in the accompanying PDF, which outlines the construction process and specifications. Whether you're a seasoned DXer or a newcomer to the hobby, the Pfeiffer Maltese Quad Antenna System offers a practical solution for enhancing your station's capabilities.

The page describes a Double-L antenna for 80 and 160 meters bands, designed by Don Toman, K2KQ, with a simple, effective, and ground system-free design. The antenna is a center-fed half-wave vertical with horizontal top and bottom sections, providing good performance without the need for an elaborate ground system.

Build your mobile antenna which outperforms Hustler by 10db and ATAS-100 by 18db. From 80 to 10m. The HB9ABX mobile HF antenna, designed for 10 to 80 meters, was developed by Felix Meyer and outperforms commercial antennas like HUSTLER and YAESU ATAS-100/120 in field tests. Made from fiberglass rods and enamelled copper wire, it includes a loading coil with adjustable taps for tuning across bands. Installation requires solid grounding, and adjustments are made via whip length and coil settings. An antenna tuner ensures optimal SWR. Users must handle fiberglass with care due to health risks. This design proved highly effective in South America and Europe.

Details the construction of a J-vertical antenna specifically for the 10-meter band, offering a practical alternative to a _Slim Jim_ design for 28 MHz. The resource outlines the use of aluminum tubing for the half-wave vertical section and coaxial cable for the quarter-wave matching section, providing specific calculations for element lengths based on frequency and coaxial cable velocity factor. It contrasts the performance of the J-vertical with center-fed dipoles and end-fed verticals, noting superior results in previous comparisons. The article further presents a more recent iteration of the J-vertical, constructed using a fiberglass pole and insulated wire, with updated dimensions for 28.8 MHz. It includes practical advice on weatherproofing connections and securing the antenna for durability against adverse conditions, referencing the survival of an original _J Vertical_ during 110 MPH winds in 1987. The SWR performance is reported as 1.1:1 at 28.6 MHz, maintaining below 1.5:1 across 28.3 to 29 MHz.

8 elements quad antenna for 2 meters band, centered on 145 Mhz

Amateur radio operators often seek reliable equipment for various modes and bands, from QRP operations to high-power DXing. Historically, Ten-Tec has been a notable manufacturer in the amateur radio market, known for its range of products including HF and VHF transceivers, RF amplifiers, and antenna analyzers. Their product line also encompassed specialized items such as QRP transceivers and kits, catering to enthusiasts of low-power communication, and antenna tuners for impedance matching. The company's offerings included test equipment vital for shack setup and maintenance, like SWR meters and RF analyzers, which assist in optimizing antenna systems and ensuring efficient power transfer. Additionally, Ten-Tec provided various accessories and components, supporting both commercial products and homebrew projects. The brand was recognized for its _made in the USA_ manufacturing, appealing to operators who prioritize domestic production. While the website currently displays limited product information, it mentions upcoming items like the _MODEL 594 PHOENIX_ and the _Tune-A-Tenna_, indicating potential future product releases.

GM4JMU shortened dipole for 40 meters band. This article illustrates in detail how to build a resonant antenna for 7.030 MHz. Cut two 10.25-meter pieces of insulated wire, wind 40 turns of wire onto plastic tubing, and connect the wire to a central insulator using a choke balun built of RG174AU coax and a ferrite toroid. Once built, the antenna is adjusted by altering the wire length to produce the lowest Standing Wave Ratio (SWR) for best performance. The guide emphasizes careful building and adjustment for the best results.

Article on a small magnetic loop antenna for forty meters band by Ben Smith

RF Concepts manufacturer of Alpha Linear Amplifiers, amateur radio RF power amplifiers, commercial power amplifiers, power meters and dummy loads.

NGC is now distributor for COMET and MALDOL brand antenna products designed, manufactured in Japan. Distributor of DAIWA brand RF SWR/power meters and switching power supplies, antennas, test equipment, antenna analyzers and more

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

10 meter modification for the Ameritron AL-811 and AL-811H amplifier. This mod apply to other Ameritron AL Series RF amplifiers and allow extension to 10 and 12 meters band.

Magnetic loops are a compromise antenna and performance will be down on a full size-wire antenna particurlarly on lower HF Bands. This article compare this magnetic loop with a full-sized wire antenna on 80 meters by VK3YE

Version 7.22 of XMLog provides a fix for an issue where the ARRL LoTW application TQSL produced error messages concerning invalid "MY-COUNTRY" values, ensuring smoother integration for award submissions. The software supports flexible log searching, allowing users to select log subsets based on any field, such as RTTY QSOs on 40 meters during a specific month, or entries for a single country with sent but unreceived QSLs. XMLog tracks DXCC, WAZ, WAS, county hunting, IOTA, and grid square awards, managing QSL sent/received status and submission status to award sponsors, with LoTW crediting for DXCC and WAS. It generates detailed reports summarizing QSL status by band and mode, identifying needed countries/states/zones, and listing critical QSOs that could boost award totals. The system also integrates with callbook services like QRZ.com (subscription required) and WM7D.net for lookups, and facilitates QSL and mailing label printing using standard or custom layouts. Further capabilities include ADIF, Excel, and CSV log import/export, a Packet Window for Internet PacketCluster nodes or TNCs with history and scripting, and vocal/CW alerts for needed QSOs based on PacketCluster spots. Rig control is supported for a wide array of Alinco, Elecraft, Flex, Heath, Icom, JRC, Kenwood, TenTec, and Yaesu transceivers, enabling frequency/mode synchronization and control. CW support is provided via a serial port interface compatible with N1MM or K1EL WinKeyer, allowing CW sending from a keyboard or pre-programmed messages.

The Flower Pot Antenna project details a portable dual-band antenna primarily operating on 10 meters, with secondary resonance near the 30-meter band. Construction involves winding RG58 coaxial cable uniformly around a large plastic flower pot, approximately 70cm high with a 60cm top diameter. The design eliminates the need for radials, contributing to its compact and lightweight nature. Key construction steps include soldering the inner conductor to the shield at one end of the wound cable and connecting the wound cable's shield to the rig cable's inner conductor at the base. An LC network, comprising a variable capacitor (0-200pF) and an inductor (10 coils, 5cm diameter, 2mm wire), is inserted between the wound cable's inner conductor and the rig cable's shield. Tuning is performed with an antenna analyzer, adjusting cable length and the variable capacitor for optimal impedance on 10 meters. The antenna performs effectively when installed horizontally.

The 80-meter loop antenna, measuring 86 meters (282 feet) of wire, effectively operates across 8 HF bands from 80 through 10 meters, despite its length being a compromise for specific bands. This design prioritizes a "low enough" SWR across multiple bands, aiming for lower SWR values on higher frequencies due to increased feedline losses. A 200-ohm feedpoint impedance provides a workable SWR on every band, with feedpoint impedances ranging from 100 ohms for lower bands to 300 ohms for higher bands. Radiation patterns for the 80-meter loop, mounted at 15 meters high, show a maximum gain of 7.6 dBi at a 90-degree takeoff angle on 80 meters, and up to 12.9 dBi at a 10-degree takeoff angle on 12 meters. This configuration supports regional contacts on 80 meters and provides good DX performance on higher bands. Practical construction notes emphasize using robust supports like trees, ensuring wire slack with _egg insulators_ for wind resilience, and employing an oversized 2 kW 4:1 _balun_ to safely handle higher SWR conditions, even with 100W transceivers. Feedline losses are minimized using _LMR-400_ coax or ladder line, with power transfer efficiency between 80% and 95%. Antenna simulations were performed using _xnec2c_, and the provided NEC file is compatible with other NEC2 derivatives. The antenna is tunable on 6 of 8 bands with an internal ATU and all 8 bands with an external autotuner like the LDG AT-200 Pro.

A solid state amplifier for HF and 6 meters band by N4IP

Demonstrates the construction and on-air performance of the _NB6Zep_ antenna, a modified 20-meter Extended Double Zepp design optimized for multi-band operation from 40 through 10 meters. The resource covers basic design principles, including dimensions of 66 feet horizontal and 5 feet vertical elements, and specifies open ladder line or TV twin lead for the transmission line. It details material selection for low-cost wire antenna construction, such as 18 AWG wire for the legs and ceramic or plastic insulators, along with practical tips for soldering connections and insulating against moisture. The author, NB6Z, shares insights from extensive _EZNEC_ modeling to optimize the antenna's total length for a 40-meter half-wave dipole footprint and feed line length for direct tuner connection. The article presents field results, including successful _PSK31_ contacts from Oregon to the East Coast on 40 and 30 meters with 50 watts, even at a low height of 6 feet. It provides detailed performance characteristics for each band, noting the _NB6Zep_'s highest gain (over 3 dB) and sharp, medium-angle lobes on 20 meters, which yielded strong DX reports to locations like Korea, Japan, and Argentina. For 17 and 15 meters, it describes a butterfly-like pattern with broad lobes, while 12 and 10 meters exhibit narrow, directional lobes in an "X" configuration. The author also shares personal experiences operating successfully for over a decade in an antenna-restricted environment using the NB6Zep and other stealth wire antennas.

Presents a catalog of **QRP** transceivers, antenna tuners, and related accessories for amateur radio operators. The product line includes the ZM-2 antenna tuner, designed for efficient impedance matching across HF bands, and the NW-series QRP transceivers, offering low-power CW operation. Additionally, the site details various ladder line insulators and specialized connectors, emphasizing robust construction for field deployment and home station use. Each product listing provides specifications, operational parameters, and pricing information. Compares the features of different **QRP transceiver** models, such as the NW-40 and NW-20, highlighting their respective band coverage and power output capabilities. The ZM-2 tuner's performance is detailed with typical SWR reduction figures for various antenna types, demonstrating its utility for portable and fixed stations. Customer testimonials and product images illustrate the practical application and build quality of EMTECH's offerings, providing insights into their durability and ease of integration into existing amateur radio setups.

The article provides detailed instructions on how to build a half-sloper antenna for the 160 meters band. It explains the concept of a sloper antenna and how it differs from a slooper. The article includes practical tips on the construction and installation of the antenna to ensure optimal performance. The intended audience is amateur radio operators interested in building their own antenna for the 160 meters band. The content is informative, practical, and focused on DIY antenna building.

EI7BA Multiband Cubical Quads projects, includes two elements quad antennas for 10 12 15 17 20 meters band. Performance considerations, detailed pictures and construction notes.

Selecting an appropriate antenna system for shortwave broadcasting involves evaluating various types based on performance, cost, and operational parameters. This resource details the critical specifications for broadcast antennas, including average and peak power ratings, directivity, takeoff angle (TOA), horizontal beamwidth, and gain, emphasizing that a 100-kW transmitter requires an antenna rated for 150 kW average and 400 kW peak. It clarifies that low TOA signals travel thousands of kilometers, while high TOA is for local coverage, and nearly all modern shortwave broadcast antennas are horizontally polarized. The article explores specific antenna types, such as Log-Periodic Antennas (LPAs), which offer wide frequency ranges (e.g., 2-30 MHz) and directional patterns with 11 dBi gain, costing from $20K to over $100K for multi-curtain versions. Dipole arrays, also known as curtain antennas, are prevalent in international broadcasting, featuring steerable beams (±15° and ±30°) and mode-switching capabilities to alter TOA, with high/low pairs costing over $1 million. Fan dipoles are noted for omnidirectional patterns, smaller size, and lower cost for low-power applications, while rhombics, though simple, require resistive termination and incur several dB of I2R losses. Balun considerations are crucial, as most communications baluns are not rated for the higher average and peak powers of AM broadcast transmitters. Modern shortwave antennas utilize durable materials like Alumoweld wire rope for radiators and support elements, avoiding copper, fiberglass, or materials prone to stretching or deterioration. Feeder systems for high-power stations often require tapered-line baluns to convert 50-ohm unbalanced power to 300-ohm balanced for connection to the antenna.

This document by W4HM explains the construction and usage of a 160 meter balanced coaxial receiving loop antenna, which can be easily adapted for the 40 and 80 meters bands. The content provides detailed instructions on building the antenna, its advantages, and how to optimize its performance for amateur radio operations. It is a valuable resource for radio amateurs looking to improve their receiving capabilities and enhance their overall radio communication experience.

The ZS6BKW multiband HF antenna, a design by ZS6BKW (G0GSF), functions effectively on multiple HF bands without requiring an Antenna Tuning Unit (ATU) for 40, 20, 17, 12, 10, and 6 meters. This antenna, approximately **27.51 meters** (90 feet) long with a 12.2-meter (40-foot) open-wire feeder, is a direct descendant of the _G5RV_ but offers superior multi-band resonance. It can be deployed as a horizontal dipole or an inverted-vee, with the latter requiring only a single support and maintaining an apex angle of at least 90 degrees to prevent signal cancellation. Performance data, recorded with an MFJ Antenna Analyser, indicates SWR values of 1:1 on 7.00 MHz (40m) and 14.06 MHz (20m), with SWR below 1.3:1 on 17m, 10m, and 6m. While primarily designed for these bands, the antenna can be adapted for 80m, 30m, and 15m with an ATU, preferably at the balanced feeder's base. The use of 450-ohm twin-lead for the feeder is recommended over 300-ohm for improved strength and reduced losses, especially in adverse weather conditions. This design, originally published in _RadCom_ in 1993 and featured in Pat Hawker’s "Antenna Topics," provides a compact and efficient solution for HF operation, particularly for those with limited space or resources.

AEA Technology Inc. is a pioneer and leading manufacturer of RF and cable test equipment for the wireless, Telco, CATV, NMR & MRI, RFID, telemetry, aviation, commercial, military, and two-way radio industries. Produces SWR Meters, Pre Amplifiers, filters, power meters and antenna testing products

The Petlowany Three-Band Burner is a simple, low-cost, trapless short vertical antenna which amazingly works on three HF bands (20, 15 and 10 meters). This web page contains pictures, performance data, and enough construction details so you can homebrew your own.

The **NW3Z** optimized wideband antenna designs, originally presented at Dayton 2001, detail Yagi configurations for the 20-meter, 15-meter, and 10-meter amateur radio bands. This resource provides access to the design files, likely containing critical parameters such as element spacing, element lengths, and boom dimensions, which are essential for replicating these directional antennas. The designs focus on achieving wide bandwidth, a desirable characteristic for contesters and DXers operating across a significant portion of each band. The content specifically references "nw3z-Antenna-DesignsDownload," indicating that the core information is available as a downloadable file, presumably in a format suitable for antenna modeling software or direct construction. Such files typically include **NEC models** or similar data, allowing for performance analysis and optimization before physical construction. The emphasis on "optimized wideband" suggests design considerations for SWR bandwidth and gain characteristics over a broader frequency range than typical narrow-band Yagis. The resource serves as a direct source for specific, proven antenna designs from a known amateur radio antenna designer, offering practical data for hams interested in building high-performance Yagi arrays for HF.

Manufacturer of communications antennas, bandpass filters, RF combiners, receiver multicouplers, diplexers, duplexers, RF connectors, RF circulators, RF isolators, RF couplers and SWR meters

A rotary trapped-dipole for 17 and 20 meters, as described by IZ7ATH, presents a practical solution for multi-band HF operation. The author, Talino, recounts his experience building this antenna for IK7ZCQ, detailing the evolution from an initial concept involving a grounded-driven element and gamma-match to a direct-fed, non-grounded design. His pragmatic approach, adapting available materials, is evident throughout the construction narrative, particularly with the use of eight tapered aluminum pipes for the driven element. Construction specifics include precise measurements for the aluminum tubing, with diameters ranging from 30 mm down to 16 mm, and a critical note on reducing tip thickness for weight optimization. The _traps_, initially a concern, are fabricated using 8 turns of RG58 coax on a 27 mm support, tuned to resonate at 18.1 MHz using a dip-meter. Talino emphasizes sealing the traps with RF glue and PVC tape to prevent water ingress, a crucial step for longevity. Field test results, conducted on a 10-meter pole in a clear garden environment, showed an SWR of 1.2:1 on 17 meters and 1.5:1 at 14.200 MHz. While SWR varied slightly when installed at Mario's QTH due to nearby objects, the antenna's performance remained commendable. The final half-dipole length is 46 cm for the 18 MHz tips, and the total weight is under 6 kg, with potential for further reduction.

AM/FM/CW QRP RF Power Amplifier for the HF 10 or 11 meterband (28MHz/27MHz)

An horizontal full wave wire loop antenna for the 80 meters band by W4HM

adsbScope is a freeware Windows application designed for processing _ADS-B_ (Automatic Dependent Surveillance-Broadcast) frames received from a compatible decoder. It identifies aircraft, calculates their real-time positions, and presents flight parameters in both alphanumeric tables and a graphical display. The software interfaces via a virtual COM port, receiving raw frames to provide detailed situational awareness, including a global coordinate grid, continental coastlines, over 4,000 **airport** locations, and major cities. Users can overlay OpenStreetMap tiles and view world state boundaries, with each tracked aircraft rendered with labels showing altitude, speed, heading, squawk code, and flight identifiers. When paired with the adsbPIC-decoder, adsbScope enables advanced hardware control, allowing users to toggle data filters for specific frames like DF17/18/19, adjust analog signal thresholds for reception fine-tuning, and manage system resets or bootloader activation directly from the PC. This functionality provides a customizable toolkit for hobbyist radar listeners, offering a robust alternative to commercial tools for processing aircraft data. The software displays up to **1090 MHz** transponder data and can track aircraft up to 250 nautical miles.

Based on VK5BR's Z-Match and designed for High RF Power covers 160 to 10 meters by VK6YSF

The Elecraft K3, a popular HF transceiver, is often benchmarked against new market entrants. This article critically compares the Kenwood TS-590S to the K3, focusing on key technical specifications and operational aspects relevant to serious amateur radio operators. The author proposes three distinct evaluation methods: a circuit diagram comparison, an independent review analysis (referencing Peter Hart, G3SJX, in RadCom), and a real-world "ear test" by experienced contest operators on 40 and 80 meters. The analysis delves into specific receiver components, including the first mixer design, RF and IF amplifier performance, and the presence of an image noise filter. It highlights the K3's switched mixer and the potential for the TS-590S to utilize similar or improved designs, such as a classic filter with enhanced selectivity. The article also scrutinizes the second mixer stage, noting the K3's SA612 chip and its associated IP3 limitations, suggesting Kenwood might achieve benefits with a different mixer architecture. Further points of comparison include DSP capabilities, where the K3's high-performing DSP with KK7P's involvement is noted against the TS-590S's potential reliance on newer IC technology but possibly less refined software. The discussion extends to DDS and PLL implementations for phase noise and spurious emissions, and the utility of a second receiver for DX chasing and contesting, acknowledging its importance for some operators while being less critical for others. The article concludes by emphasizing personal preference in equipment selection.

Contruction manual to build a 4:1 balun, it has good performance from 160 through 10 meters.

Over 75 years of engineering expertise underpins Bird Electronic's offerings in RF power measurement, critical for maintaining peak performance in amateur radio stations and professional communication systems. The company specializes in a range of test equipment, including wattmeters, SWR meters, and antenna analyzers, essential for optimizing antenna systems and ensuring efficient power transfer. Their product line extends to various RF components such as filters, cables, and connectors, all designed to meet stringent technical specifications for reliability and accuracy across diverse frequency bands. Bird Electronic's instruments, like the _Bird 43_ Thruline Wattmeter, are widely recognized for their robust construction and precise measurement capabilities, providing hams with confidence in their station's operational parameters. These tools enable accurate assessment of forward and reflected power, SWR, and modulation characteristics, which are vital for troubleshooting and maximizing radiated power. The company's commitment to innovation ensures that its products remain relevant for modern RF challenges, from HF through microwave applications, supporting both traditional analog and advanced digital modes.