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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 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.

A 5/8 wave stacked j-pole antenna plan

An effective 10-20m DX antenna for deed restricted lots. The article by K7ZB introduces a simple 10-20m DX antenna suitable for deed-restricted lots. The antenna, a 15' vertical design, facilitated contacts with over 200 countries worldwide. Its design employs a telescopic aluminum tube and radial wires for multi-band operation, requiring an external antenna tuner for optimal performance. The mounting scheme and construction details ensure effectiveness and ease of use.

Details the construction of a **multiband vertical** antenna, specifically designed for stealth operation in a rented property, covering 80m, 60m, 40m, and 30m. The author, N3OX, leverages a 12m Spiderbeam telescoping fiberglass pole as the primary support, noting its sturdiness compared to typical fishing rods while remaining light enough for quick deployment and takedown. The radiating element is a 14 gauge Flex-Weave wire, attached to the pole's top with a rubber grommet, and fed by 27 bare 18 gauge radials spread across a 40-foot square backyard. N3OX describes the impedance matching solution, opting for custom-built L-networks over a remote tuner to enable fast bandswitching. Using an MFJ-259B and EZNEC modeling, base impedances were measured and component values calculated with G4FGQ's L_TUNER and SOLNOID_3 programs. The 80m coil is wound on a 3.5-inch PVC form, while the 30m, 40m, and 60m coils are air-wound, self-supporting #10 wire. Variable capacitors are incorporated for 40m and 30m shunt elements, with the 60m impedance matched by a series inductor. The project includes a **servo-controlled** homebrew band switch, utilizing a two-pole 12-position ceramic wafer switch for remote operation, addressing the limited 80m bandwidth. The entire matching network is housed in a weather-resistant shelter constructed from lumber and aluminum flashing. N3OX reports good DX results at 100W, estimating the total cost between $150 and $250, depending on existing parts.

This resource details the fundamental aspects of deploying longwire antennas, emphasizing ease of construction and installation for shortwave listening (SWL) and broadcast reception. It covers wire gauge selection, suggesting 14 to 24 AWG for general use, with heavier gauges (14-20 AWG) for permanent outdoor installations. Guidance is provided for various deployment scenarios, including indoor setups where the wire can be run around a room, temporary outdoor installations from balconies using light 18-24 AWG wire, and permanent outdoor configurations requiring higher placement and slack for tree movement. Feeding methods are discussed, recommending coaxial cable (50-75 ohms) to mitigate man-made interference, with instructions for connecting only the center conductor to the longwire. Safety precautions are highlighted, particularly avoiding contact with power lines and conductive materials, and managing static electricity buildup by unplugging the antenna after use and bleeding off charges before connection. The article also advises against using outdoor longwires during thunderstorms or snowstorms due to static and lightning risks. Optimal height considerations are presented, advocating for the highest safe placement, ideally a couple of feet above underlying structures, to maintain free air space. The text mentions a personal setup with one end at a roof peak (20 feet) and the other at a 17-foot mast, illustrating practical deployment without strict height requirements beyond safety and clearance.

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.

MRP40, a successor to the well-regarded MRP37, offers robust Morse code decoding capabilities by processing analog audio signals via a sound card and displaying the decoded text on a computer monitor. My own field tests with similar sound card decoders confirm that the quality of the audio input and proper signal conditioning are paramount for achieving reliable decoding, especially with _weak signals_. The program also facilitates CW transmission, converting keyboard input into Morse code to key a transceiver, a feature I've found useful for practicing sending or for quick contest exchanges. Beyond its core CW functions, MRP40 incorporates a convenient mini-logbook, which automatically checks for prior contacts and allows for quick logging by double-clicking callsigns in the receive window. This integration streamlines the logging process, a significant advantage during busy operating sessions where every second counts. The software also generates Morse tones using the sound card, a handy utility for testing tone sequences or for basic code practice. Additionally, the suite includes a DTMF decoder and generator, which can be used for decoding telephone dial tones or data transmissions over amateur radio frequencies. It also features MF-TeleType, a sound card-based audio data modem for transmitting text via radio, utilizing a principle similar to DTMF for encoding and decoding, offering a simple method for digital text communication.

The 144-430 portable j-pole antenna is designed for amateur radio operators seeking a lightweight and efficient solution for VHF and UHF communications. This antenna is particularly useful for portable operations, allowing hams to set up quickly in various locations while maintaining excellent performance. Constructed from readily available materials, it can be easily homebrewed, making it an ideal project for both beginners and experienced operators alike. The j-pole design offers a simple yet effective configuration that provides a good match across the 144 MHz and 430 MHz bands. Its vertical polarization and omnidirectional radiation pattern make it suitable for local communications and simplex operations. This antenna can be deployed in various environments, whether in the field or at home, and is well-suited for mobile applications. With proper construction techniques, operators can achieve optimal performance, enhancing their ability to make contacts during contests or casual QSOs.

This PDF article from April 2001 QST details the construction of the "NJQRP Squirt," a reduced-size 80-meter inverted-V dipole antenna. The resource provides a general construction sketch, a photograph of the assembled antenna, and specific dimensions for PC-board insulators. The antenna consists of two wire legs, each approximately **34 feet long**, separated by 90 degrees, fed at the center. It is designed for operation on 80 meters (3.5-4.0 MHz) as a quarter-wavelength antenna, requiring a low-loss feedline and an external antenna tuner due to its non-resonant feedpoint impedance. Construction utilizes readily available materials, including 1/16-inch glass-epoxy PC board for end and center insulators, and #20 or #22 insulated hookup wire for the elements. The feedline specified is 300-ohm TV flat ribbon line, with a note on potential trimming for tuner compatibility. N2CX reports the antenna's center should be elevated to at least **20 feet**, with ends no lower than seven feet above ground, resulting in a ground footprint of approximately 50 feet wide. The design prioritizes NVIS propagation for local 80-meter contacts. DXZone Focus: PDF Article | 80m Inverted-V Dipole | Construction Notes | 34 ft element length

DXKeeper is a robust, freeware logging application designed for amateur radio operators, providing extensive capabilities for managing two-way radio contacts. It records and organizes QSO data, integrates with various callbook CD-ROMs like _HamCall_ and QRZ.com for automatic data population, and supports real-time logging from digital mode software such as MMTTY and MixW. The software runs on Windows NT through 8, supporting both 32-bit and 64-bit systems, and is a core component of the DXLab Suite. This application offers detailed tracking for numerous awards, including DXCC, WAZ, WAS, and IOTA, highlighting needed entities and automating the QSL process. It generates QSL cards and labels, addresses envelopes, and facilitates uploading and downloading of QSO confirmations with eQSL.cc and Logbook of the World (LotW). DXKeeper also interoperates seamlessly with other DXLab Suite members like Commander for transceiver control and SpotCollector for DX spot aggregation, significantly streamlining contest and DXing operations by providing a unified interface for logging and station management, including over **40** supported awards and **3** major online QSL services.

Select your favorite satellite and watch its trajectory on Google Maps in real time! Includes ISS tracking, Weather, Geostationary, GPS Military, and of course Amateur radio satellites. N2YO provides comprehensive real-time satellite tracking with particular emphasis on amateur radio satellites. The service offers precise pass predictions calculated for user-specific locations, displaying upcoming passes with azimuth, elevation, and duration data essential for ham operators planning satellite contacts. N2YO features dedicated tracking for amateur radio satellites including FM, linear transponder, and digital satellites, with frequency information and downlink/uplink details. The platform delivers live tracking visualizations on interactive maps, Doppler shift calculations, and automated email notifications for upcoming passes. This free resource integrates weather satellite tracking alongside NOAA imagery, making it invaluable for radio enthusiasts pursuing satellite communications.

PinPointAPRS offers a modern APRS solution with unique features for tracking and communicating with people using Ham Radio equipment. It is free for individual use and can be used as a tactical communications tool during emergencies. The software does not require an internet connection and is self-contained, making it versatile for various scenarios.

Explains what amateur radio entails, detailing its dual role as a hobby and a public service, enabling communication among licensed operators using diverse radio equipment for self-training, recreation, and public service. It clarifies that ham radio operators require a government license, regulated globally by the ITU via the IARU, and outlines the privileges and responsibilities that come with operating an amateur radio station, including restrictions against commercial use and broadcasting to the general public. The resource then enumerates various activities hams engage in, such as worldwide HF communication, local VHF/UHF contacts, QRP operation, Packet Radio, Amateur Television, Slow Scan TV, contesting, and satellite communications. It also covers emergency and volunteer services, traffic handling, and the process of becoming a licensed amateur radio operator in the United States, mentioning local clubs, Elmers, and self-study as preparation methods for the FCC multiple-choice test.

DX4WIN provides a robust logging solution for amateur radio operators engaged in DXing and contesting. This software streamlines the process of recording contacts, managing QSLs, and tracking award progress, which is essential for operators aiming for achievements like _DXCC_ or _WAZ_. Its intuitive interface simplifies data entry and retrieval, making it accessible for hams across all experience levels. The program integrates features for contest operation, including real-time scoring and duplicate checking, which can significantly improve a station's performance during major events. Operators can log thousands of QSOs efficiently, with support for various digital and analog modes. The software also offers tools for managing station equipment, such as rig control, to enhance operational flow. DX4WIN has been continuously developed, with updates addressing new operating practices and technologies. It supports ADIF export for compatibility with other logging platforms and award submission systems.

Over 16.7 million callsigns are indexed within the HamCall World-Wide Callsign Database, a long-standing resource for amateur radio operators. This online tool facilitates rapid lookups of callsign data, including operator details and QSL photos, which are crucial for confirming contacts and pursuing operating awards. The database integrates FCC updates as they are released, ensuring timely access to current licensing information. The platform also features a live **DX cluster** displaying recent spots across various bands, from 160m to 3cm, with specific spot counts for active bands like 15m (50 spots) and 10m (46 spots). Users can view **band activity** summaries, providing an immediate overview of propagation conditions and active frequencies. Additionally, the service provides access to a hamfest calendar and amateur radio news updates, making it a multi-faceted resource for daily operating and event planning. Since 1989, the HamCall DVD has supported this server, alongside HamCall.net Gold Memberships, demonstrating a sustained commitment to providing comprehensive callsign data.

This Vertical antenna design by David Reid for lower bands focuses on achieving effective DX communication by optimizing the antenna low-angle radiation for long-distance contacts. The design incorporates techniques like linear loading and capacity hats to reduce the antenna's height while maintaining performance, especially on 40m and 80m bands. Building a solid ground plane and using quality materials ensure efficiency and durability. Although vertical antennas can be complex to build, this project simplifies the process, making it accessible for ham operators seeking strong, reliable signals.

Presents a web-based DX cluster interface, F5LEN Webcluster, which functions as a member node within the broader European DX Cluster network. It displays current DX spots across a wide range of amateur radio bands, from VLF through SHF, including specific bands like 1.8 MHz, 144 MHz, and 10 GHz, as well as satellite operations on QO-100. The service offers filtering options for various modes and activities, such as CW, QRP, IOTA, and specific VHF/UHF bands. Operators can access real-time propagation data, including Solar Flux Index (SFI), Sunspot Number (SSN), Kp index, and Auroral activity (Au), alongside tools for solar forecasts and tropospheric ducting predictions. The platform facilitates DX spotting by providing a centralized point for sharing and viewing contact information, aiding in DX hunting and contest operations. It also includes links to an Atlas, Sun tools, and a mobile version for portable access.

Presents a practical design for a **crossed-dipole turnstile antenna** specifically engineered for 2-meter Amateur Radio Direction Finding (ARDF) events. The author, WB6RDV, details a robust, omnidirectional, horizontally-polarized antenna, addressing the international ARDF rules requiring such characteristics at a height of two to three meters above ground. This contrasts with the vertical polarization often used in Southern California, highlighting the design's adherence to specific event requirements. The electrical design employs a classic crossed-dipole with a 75-ohm phasing section, resulting in a slight impedance mismatch and an SWR of approximately 1.3:1 with a 50-ohm feedline. Construction utilizes readily available and inexpensive PVC plumbing components and 1/8-inch bronze welding rod for elements. The guide provides step-by-step instructions for mechanical assembly, including drilling element holes at precise 90-degree spacing and preparing the RG-179 matching section. WB6RDV shares insights from his own build experience, discussing the use of plated brass versus aluminum spacers for element attachment and the effectiveness of crimping as an alternative to soldering. The document also covers final assembly, including the integration of ferrite beads as a choke balun and options for weatherproofing and alternative mounting configurations, emphasizing the adaptability of the design for other VHF bands through scaling.

Amateur Contact Log (AC Log) by N3FJP is a commercial Windows-based general logging program designed for amateur radio operators, supporting Windows 7 through 11. It provides comprehensive tracking for various operating awards, including Worked All States (WAS), Worked All Counties, Worked All Countries (WAC), DXCC, VUCC, Grids, Zones, IOTAs, and Lighthouses. The software features a customizable user interface, allowing operators to display specific data fields and adjust font sizes. It includes built-in databases for counties and countries, facilitates queries by band, mode, or power level, and offers a bearing and distance calculator for DX contacts. AC Log also provides DX spotting via Telnet or packet TNC, supports keyboard CW, and can play wave files. The program offers full support for ADIF import and export, enabling seamless integration with external services like eQSL, QRZ, Club Log, and the ARRL's Logbook of the World (LoTW) for QSO uploads and confirmation downloads. It interfaces with popular transceivers from Elecraft, Icom, Kenwood, Ten Tec, and Yaesu, and connects with digital mode software such as WSJT-X, Fldigi, and JTAlert via API. AC Log includes a Net Manager form for group logging, prints basic QSL label strips, and integrates with QRZ and Ham Call lookup services. The software is fully networkable for multi-PC operation, supports Parks on the Air (POTA) logging, and displays worked entities and DX spots on a real-time world map. Full featured Trial version available for 45 days

Presents the KE4UYP linear-loaded vertical antenna design, which introduces very little loss on 80 or 160 meters, achieving an overall radiation efficiency of 80% to 85%. This design addresses common pitfalls of traditional base-fed verticals by placing the majority of the current at the top of the antenna, eliminating the heavy reliance on extensive ground radial systems. The author's initial 10-meter model, only three feet tall, yielded 5/9 signal reports to Anchorage, AK, and Europe, confirming its effectiveness. The antenna incorporates both vertically and horizontally polarized radiators, with a 1/4 wavelength horizontal counterpoise located at the feed-point, near the top, to create an almost totally omnidirectional pattern with high wave angle horizontally polarized radiation. This dual polarization ensures even illumination across all take-off angles, making it effective for both local contacts and **DXing**. The vertical element is linear loaded, adding capacitance reactance and making it longer than the horizontal element to achieve resonance and raise the feed-point impedance to 50 ohms. Fine-tuning the antenna requires careful adjustment, as tower reactance can vary. The article suggests starting with 80 feet for 80m and 170 feet for 160m for the vertical wire, then trimming for resonance. Bandwidth specifications include 300 kHz under 2:1 **SWR** on 80m and 100 kHz on 160m when suspended between trees, or 150 kHz on 80m when side-mounted on a tower.

The 75 meter dipole at K7ZB was put up to meet the need for making contacts with friends in the Southwest and Southern California. As usual, it had to be put up so no one can see it from the surrounding neighborhood.

This step-by-step tutorial contains everything you need, not only to survive that first contact, but also to learn to enjoy Code and actually do it well. Even if you detested learning it in the first place

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.

Ham Station description of HB9ABX and CE3CWF, magnetic loop antenna details, Free Energy devices, Pictures from Switzerland and Chile.

Constructing and designing full size, single band stacked yagi antenna arrays

Mods.DK serves as a central repository for **amateur radio modifications**, offering a substantial collection of user-contributed articles. Hams can find detailed instructions for various equipment, from transceivers by Yaesu, Kenwood, and Icom to microphones and power supplies. The database, currently holding 6230 articles, facilitates searching for specific equipment modifications, such as enabling out-of-band receive and transmit capabilities or integrating high-speed packet modems for enhanced data communications. Many entries focus on achieving better performance from existing gear, often detailing how to expand frequency coverage for MARS/CAP operations or optimize radios for 9600 baud packet. The site also includes repair instructions and general improvements for a wide array of HAM rigs and modems, reflecting a community-driven effort to share technical knowledge. Users are cautioned that modifications are not verified by Mods.DK and are undertaken at one's own risk, with potential legal implications depending on local regulations. The platform emphasizes community support, encouraging direct contact with authors or forum discussions for troubleshooting.

WSJT-X, a creation of K1JT, offers specialized digital protocols meticulously optimized for challenging propagation paths such as EME (moonbounce), meteor scatter, and ionospheric scatter. This software excels at VHF/UHF frequencies, and also provides robust performance for LF, MF, and HF DXing, enabling contacts far below the audible threshold. The program decodes signals from ionized meteor trails and steady signals more than 10 dB below the audible threshold, a testament to its advanced digital signal processing. It integrates nearly all popular features from its predecessors, WSJT and WSPR, while adding comprehensive rig control and numerous other enhancements for the serious weak signal operator. Available for Windows, Linux, and Mac OS X, WSJT-X is an open-source project, allowing hams worldwide to download the latest versions and engage in cutting-edge weak signal communication.

Journal is a **freeware logbook software** designed for Windows operating systems, providing amateur radio operators with a robust tool for managing their contacts. It supports both real-time logging during a QSO and post-event data entry, allowing flexibility for different operating styles. The software facilitates the creation of QSL cards and address labels directly from logged data, streamlining the QSLing process. Additionally, it can generate log sheets specifically formatted for the RSGB VHF-UHF-SHF Competition, which is beneficial for contesters. Derek, G7LFC, developed Journal to be Year 2000 compliant, ensuring its longevity and reliability for logging contacts across different eras. The program supports various operating modes, making it versatile for general DXing, contesting, and everyday ragchewing. Its ability to produce competition-specific logs and QSL materials makes it a practical utility for active operators.

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.

Examines the current geopolitical landscape of Armenia, offering detailed reports on regional developments and internal political discourse. The station, _Radio Azatutyun_, covers critical discussions such as the potential for conflict in September, with one source suggesting a "war is coming, it won't be delayed," alongside ongoing debates about Armenia-EU visa liberalization, which is projected to require "another 2-3 years" for completion. It also highlights the contentious rhetoric surrounding the Prime Minister's interactions with displaced persons from Artsakh. The resource delves into significant international relations, including discussions between Bayramov and Araghchi on regional situations, and Iran's denial of recent negotiations with the US. It also features updates on former President Trump's demands for an additional **$200 billion** for defense and his assertion that "regime change" in Iran is effectively underway. Further content includes analyses of drone attacks in Baku, the proposed new Constitution, and local issues such as the delayed reconstruction of Gyumri's central market and the persistent problem of Vanadzor's temporary kindergartens. The platform also hosts podcasts like "The Choice is Yours," exploring the reliability of pre-election polls.

Based on a design by JM1SZY for 50 MHz that he developed using YO

A 144 MHz kilowatt amplifier project details the construction and performance of a high-power VHF linear using the GU74b tetrode. This Russian tube, equivalent to the Svetlana 4CX800, is noted for its conservative datasheet ratings, performing closer to 800-1000W anode dissipation in practical applications. The design prioritizes compactness and achieves 1.2 kW output with only 20W of drive power, demonstrating a 70% efficiency at 2.5 kV plate voltage. The amplifier has been successfully deployed in demanding _EME_ (Earth-Moon-Earth) operations since June 1994. Challenges encountered during development included achieving stability with a grid-1 input configuration. The author, _CT1DMK_, opted not to publish the full design due to its complexity, suggesting it might be difficult for less experienced builders to replicate successfully. However, he invites direct contact for those with specific interest in the design. Future plans include a "144MHz GS35b compact amplifier" project, promising another kilowatt-plus design. This resource offers insights into high-power VHF amplifier construction and the practical application of specific power tubes.

The Double Bazooka Dipole is a very efficient single band antenna which is very quite, and does not require the use of a balun. This antenna consists of coax (RG58) or other 50 ohm type with the shield split at the center and the feedline attached to the open ends

FT2 is an innovative digital mode for amateur radio, developed by IU8LMC with support from ARI Caserta. It utilizes the same codec as FT8 and FT4 but compresses the transmission cycle to just 3.8 seconds, allowing for a complete QSO in as little as 11 seconds. This remarkable speed enables operators to achieve approximately 240 QSOs per hour, making it particularly advantageous for contests and DXpeditions. The FT2 protocol has been rigorously tested on-air, with successful QSOs verified down to -12 dB SNR on both 40m and 80m bands. The mode's efficiency and speed are a significant advancement in digital communications, providing a new tool for amateur radio operators looking to maximize their contact rates. As an experimental release, the software is subject to updates, ensuring continuous improvement and adaptation to user feedback.

Facilitates efficient logging of amateur radio contacts, offering a robust solution for hams managing their station activities. The software integrates _CAT control_ capabilities, allowing direct interfacing with popular transceivers from manufacturers like Yaesu, Icom, and Kenwood. This feature streamlines the logging process by automatically capturing frequency, mode, and other QSO details directly from the radio, reducing manual entry errors and improving operational efficiency during contests or DXing. _HAM-LCT_ includes a comprehensive database, enabling users to store and retrieve contact information, QSL data, and other relevant details for each QSO. The program supports various operating modes and provides tools for searching and filtering log entries, which is beneficial for award tracking and station analysis. Its design focuses on providing a user-friendly interface for everyday logging tasks. While the original author, _HB9CQV_, has discontinued development of HAM-LCT in favor of a newer logging application, this version remains available as a functional freeware option for Windows users seeking a dedicated logbook with integrated rig control.

A 6 elements VHF Yagi antenna designed with YAGIMAX 3 and made by SV1XY with excellent results on local and satellites contacts like UO-14 and AO-27

This Multiband Cubical Quad antenna a boomless Quad design with glass-fibre arms and a single coax wire connected to a remote antenna switch. This aerial work on 8 bands and has a 60-degree beam width. Despite achieving critical technical requirements, the antenna's three-dimensional structure presents obstacles, such as installation issues on fixed towers and risk of frost damage. The spider framework is built of stainless steel, with a compact 18-inch boom and strong angle iron arms. Tait use a variety of methods to fasten element wires and suggests placing them on the outside of the spreaders for improved insulation. The use of nylon twine or parachute cord between key attachment points allows for adjustable separation between pieces.

Jack Wagoner WB8FSV, a very well done article on how start a CW QSO, how to answer a CQ, how call your CQ and more. A must reading for beginners

What is NVIS Near Vertical Incident Skywave. This article on NVIS (Near Vertical Incidence Skywave) explores its role in short-range HF communication, covering 0-200 miles. NVIS utilizes antennas with high radiation angles and frequencies below the ionospheric critical frequency to achieve reliable local contact. He details optimal antennas, like low dipoles, and practical tips for maximizing NVIS performance, emphasizing its advantages such as reduced noise and independent operation without repeaters. However, challenges include frequency sensitivity and the need for appropriate antenna setups at both ends for effective communication.

DXMaps.com presents a dynamic, real-time mapping service for amateur radio DX spots, integrating data from traditional DX clusters, _PSK Reporter_, and WSPR networks. The platform visually plots global QSO and SWL activity, enabling users to observe propagation conditions across various bands, from 2200m to >450 MHz. It offers distinct overlays such as the magnetic equator, gray line, moon footprint for EME, and VOACAP propagation predictions, providing a comprehensive view of radio wave behavior. The service allows granular filtering of displayed spots, including options to show only DX-Cluster data, PSK Reporter activity, or WSPR signals. Users can refine the map view by selecting specific bands (e.g., 160m, 20m, 6m, 2m), limiting spots to the last 15 minutes, or displaying only contacts exceeding **2600 km**. Additional features include the ability to toggle grid squares, aurora forecasts, and various amateur radio zones (CQ, ITU). Distinctively, the resource updates automatically every minute, ensuring current propagation intelligence without manual refresh. It also supports specialized views for EME, ionospheric scatter, and aircraft scatter, alongside FM DX and APRS activity. The platform emphasizes the importance of accurate locator information in DX spots to enhance data quality and offers a user manual and FAQ for guidance.

Stacking and phasing HF and 6m arrays antenna switches and contesting devices. Custom low band antenna arrays, bandpass filters,commercial/Mil STd filters,microwave components, commercial broadcast filters.

F6EZX presents a detailed account of constructing a compact, multi-band _Levy antenna_ for portable holiday operations, specifically addressing issues with local QRM from a previous _Deltaloop_ setup. The article outlines the design criteria, including multi-band operation on 40m, 30m, 17m, 15m, 12m, and 10m, a symmetrical configuration to reduce interference, and a low take-off angle for DX. Construction involves 2x 10.3m radiating elements and a 15.3m open-wire feeder (ladder line) with 7cm spacing, made from 1.5mm2 copper wire and foam pipe insulation spacers. Theoretical calculations, referencing F9HJ's "_Les antennes Levy_" book, guide the determination of element lengths and feeder impedance characteristics, aiming for a good match across bands with a commercial antenna tuner. Initial field tests with the _VCI Vectronics VC300DLP_ tuner showed a 1:1 SWR from 80m to 10m, with some difficulty on 17m. The antenna, mounted as a 45-degree slopper with the high point at 12m, successfully facilitated DX contacts to South America, particularly Chile and Argentina, suggesting a lower take-off angle compared to the previous Deltaloop which favored Brazil. The Levy antenna significantly reduced TVI/RFI, attributed to its improved symmetry and greater distance from the QRA. While signal reports on 15m and 20m were 1-2 S-points lower than the Deltaloop, its performance on 40m and 30m was comparable, fulfilling the design goals for a portable, low-cost, multi-band solution.

The QM7 antenna is a simple 7 elements Yagi with 3.70 m boom length for the lower 144 MHz SSB/MGM band, used it mainly for Sporadic-E and MS contacts. It exhibits a forward gain of 11.35 dBd; i.e. 13.5 dB forward gain over the isotropic radiator, while the F/R is about 12.5 dB

WinLink 2000 employs Stations World-wide to provide an HF/VHF/UHF digital radio Interface into the Internet Email system for the mobile radio operator. Features include binary and graphic file attachments, APRS position reporting and over 340 downloadable WX products. The mode used is Pactor I and Pactor II.

A stacked Jpole antenna plan by Gary - KGØZP

Tarheel Antennas presents its product line of motorized **screwdriver antennas** and stainless steel mounting solutions, engineered for both amateur radio operators and commercial users. The resource details the manufacturing process, emphasizing in-house CNC machining and the use of quality materials for durability and performance. It highlights the company's commitment to U.S.-based manufacturing, with products built in St. Joseph, MO, since 2008. The site provides essential contact information for sales and technical support, including email addresses and phone numbers. It also includes a mailing address for physical correspondence. While noting a temporary absence from the Dayton Hamvention in 2024, the company expresses intent to return in 2026, indicating engagement with the amateur radio community.

Demonstrates a **DX cluster** web service providing real-time amateur radio spot reports, propagation information, and solar data. The platform integrates features such as a gray line map, **DXCC** tracking, and a personal logbook, allowing users to manage their confirmed entities and contacts. It supports various bands from 160m to 70cm, including specific filters for modes like FT8/FT4, and offers both web and Telnet access for spotting and monitoring. The service provides graphical representations of spot reports, detailing activity across different frequency bands and modes (CW, SSB, digital). Registered users gain access to advanced functionalities, including personalized filters and tools for calculating DXCC status. The platform also includes a classifieds section and options for mobile access, catering to a broad range of amateur radio operators interested in DXing and contesting.

A 2-meter Turnstile antenna, detailed for amateur satellite communication, offers a straightforward build for those looking to engage with orbiting transponders. The author, WB8ERJ, shares his personal design and construction methods, emphasizing the antenna's simplicity and effectiveness for LEO (Low Earth Orbit) satellite work. This design provides a circularly polarized signal, crucial for mitigating _Faraday rotation_ and signal fading often encountered with linearly polarized antennas when tracking satellites. Construction involves readily available materials like PVC pipe and copper wire, making it an accessible project for many hams. The article includes practical advice on element spacing and feed point considerations, drawing from the author's hands-on experience in the shack and field. It highlights the antenna's utility for receiving signals from various amateur satellites, including the popular AO-91 and AO-92. The Turnstile's inherent omnidirectional pattern in the horizontal plane, combined with its circular polarization, yields consistent signal reception, often resulting in **stronger decodes** and **more reliable contacts** compared to basic dipoles or verticals.