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This paper discusses the sources of feed line currents and the methods used to control them.

The radio-amatori.it forum provides a platform for Italian radio amateurs to discuss various topics. The forum's content includes general interest discussions relevant to the amateur radio community in Italy. This resource facilitates interaction among hams, allowing for the exchange of information and experiences within a regional context. Currently, the domain radio-amatori.it is listed for sale, indicating a potential change in ownership or operational status. This situation suggests the forum's long-term availability or content stability may be uncertain.

Over 100 currently valid callsigns for the Bailiwick of Guernsey are listed, encompassing full, intermediate, and foundation licenses, alongside special event and club station calls. The resource clarifies various callsign types, such as 2U0*** for intermediate licensees with a 50-watt limit and GU0*** for full licensees operating up to **400 watts**. This detailed compilation also includes specific QSL routing instructions for visiting operators and past residents, often referencing their home callsigns like _G4DIY_ or _DJ8NK_. The callbook further acknowledges "silent keys," providing a respectful record of former Guernsey amateurs, complete with their callsigns and dates of passing where available. It also lists local repeaters and provides important QSL bureau information, noting that only US dollar bills are accepted for direct QSLs, not English stamps or Euros. For full addresses, the resource directs users to _QRZ.com_, emphasizing that the provided information is offered in good faith.

This resource presents a placeholder page for the _Tobacco Valley Amateur Radio Club_ (TVARC), signaling the future establishment of an online presence for this amateur radio organization. The page currently displays a "Coming Soon" message, indicating that the club's official website is in development. It serves as a preliminary marker for the club's digital footprint, suggesting an upcoming platform for members and prospective hams. The current state of the page offers no technical details, operational information, or specific club activities. It functions solely as a temporary landing page, prompting site owners to log in for launch and visitors to check back later. The resource does not provide any data on club repeaters, meeting schedules, or special events, nor does it detail any past achievements like **DX contacts** or **contest scores**.

The K5BSA Venturing Crew 73 resource, intended for a ham radio club based in Richardson, Texas, currently presents a 404 "Page Cannot Be Found" error. This status indicates the original content, which likely detailed club activities, membership information, or amateur radio projects, is no longer accessible at the specified URL. The page provides general information about _QSL.net_ hosting services, noting it supports over 30,000 websites for amateur radio operators and organizations. The error message suggests contacting the website owner directly or using an internet search to locate the intended content. It also clarifies that QSL.net cannot assist in finding specific missing pages hosted by individual users, as each site is independently maintained. The platform offers its email and web services without cost to the amateur radio community. Despite the error, the page includes links to general QSL.net resources such as "About QSL.net," "The Help Page," and "EMail Mailing Lists." It also features a prominent "Make a Donation" option, emphasizing that while services are free, user contributions are encouraged to support the hosting infrastructure.

Details the Highline Amateur Radio Club (HARC), an organization dedicated to public service through Amateur Radio and community engagement for radio enthusiasts. The club conducts a monthly general meeting on the 4th Saturday at 10 AM at Burien Fire Station 28. HARC also hosts a weekly net on Tuesdays at 7:30 PM, operating on **146.660 MHz** with a -600 kHz offset and a 103.5 Hz **CTCSS tone**. Additionally, members gather for a weekly breakfast on Fridays at 9:30 AM at Tuscany at Des Moines Creek. The resource provides current weather conditions for Burien, WA, displaying temperature, wind chill, and a three-day forecast from the National Weather Service Seattle/Tacoma Office. It also links to the latest ARRL Newsletter, noting a system breach in May 2024 affecting archived links. The club's activities include regular meetings, on-air nets, and social gatherings, supporting local amateur radio operations and community involvement.

The current page presents a domain name for sale, rather than providing amateur radio content. It outlines the process for acquiring the _ae5x.com_ domain, including a direct purchase price of **$3,795** or a 24-month payment plan at $158.13 per month with 0% interest. The service emphasizes quick delivery, secure shopping via SSL encryption, and a 30-day money-back guarantee. Information regarding domain transfers to other registrars like GoDaddy is provided, noting that transfers can take up to 5 days and payment plan domains are ineligible until fully paid. The purchase includes only the domain name, with hosting and web design services needing to be sourced separately. Privacy protection options through NameBright.com are also mentioned.

The resource, "Conventional Use of Transmission Line," meticulously details the operational principles of transmission lines, emphasizing the Transverse Electromagnetic (TEM) mode of energy transfer. It clarifies that for a line to function purely as a transmission line, all currents must be confined internally, with external fields ideally zero. The discussion differentiates between balanced and unbalanced lines, asserting that while both require equal and opposite currents within the conductors, the key distinction lies in the voltage relationship of each conductor to the surrounding environment. It highlights that a good antenna pattern does not inherently confirm proper feeder balance, and that common-mode currents can lead to RF in the shack and increased noise levels, even without pattern distortion. The article further explains that a transmission line can become a radiating conductor if energy is applied in a non-TEM mode, leading to common-mode issues. It cites classic texts like Jordan and Balmain's "_Electromagnetic Waves and Radiating Systems_" and Kraus's "_Antennas_" to support its definitions of TEM mode operation. The content also explores non-transmission line applications of parallel or concentric conductors, such as _coaxial dipoles_ and _folded dipoles_, which intentionally operate in non-TEM modes for antenna functionality. The author, _W8JI_, stresses that simply measuring equal currents is insufficient to confirm a balanced feeder; phase and voltage balance to ground are equally critical.

The EA8ALP personal page, hosted on QSL.net, is currently inaccessible, presenting a 404 "Page Cannot Be Found" error. This resource was intended to feature Adelto, an amateur radio operator from the Canary Islands, likely detailing his station, operating activities, or other personal ham radio interests. The QSL.net platform, which hosts over 30,000 amateur radio websites, provides free web and email services to operators and organizations, relying on donations for support. While the specific content of EA8ALP's page is unavailable, the platform's structure suggests it would typically include information relevant to **DXing** and **contesting**, common interests for operators in geographically desirable locations like the Canary Islands. Users encountering this error are advised to contact the website owner directly or use an internet search to locate the intended content, as QSL.net cannot assist with individual site content issues.

This page provides a detailed guide on the Guanella Current Balun for ham radio operators. The author shares very nice schematics, photos, and explanations on the construction and use of this type of balun. The content explains when a balun is needed and how it can help with common-mode currents in antenna systems. It also discusses the construction process, including winding the balun around a ferrite core. This resource is useful for hams looking to improve their antenna systems and reduce common-mode currents for better performance. This article is in Dutch.

Operating in a Single Operator Two Radios (SO2R) setup, especially with beverage antennas, often exposes the receiving radio's front-end to significant RF energy from the transmitting radio. This resource details a practical, homebrew receiver protection circuit designed to mitigate this risk. The core of the design involves a non-inductive 2W 22 Ohm carbon composition resistor in series with the RX antenna line, followed by two stacks of four fast-switching diodes (e.g., _1N914_) configured in opposite polarizations. This arrangement effectively clamps the incoming voltage to approximately 2.8 V peak-to-peak, safeguarding sensitive receiver input components. The series resistor plays a crucial role by absorbing excess power, preventing the diodes from exceeding their current ratings and potentially failing open, which would leave the receiver unprotected. The author, _N4KG_, measured up to 50 watts of coupled power between 80M slopers on the same tower, highlighting the necessity of such protection. The design is presented as a cost-effective solution to prevent damage to receiver input transformers, with the author noting successful protection of a receiver even after a resistor showed signs of overheating. This simple circuit can be integrated via a transverter plug, offering a robust defense against high RF input.

Covers the WB2JKJ Educom HF Net, which operates on 7.238 MHz and 21.395 MHz. This resource highlights the activities of The Radio Club of Junior High School 22 NYC, Inc., a non-profit organization established in 1980. The club's mission, "Education Thru Communication" (EDUCOM), focuses on integrating amateur radio into schools across the nation as a teaching theme. WB2JKJ, Joe Fairclough, founded and presides over this club, which is recognized as NYC's largest ham radio club. The site also provides access to the "APPLE SLICE NewsletterCurrent Edition" and information on how to support the organization. It includes a scrapbook section and contact details for further engagement. The content was last updated on May 5, 2023, reflecting recent activity.

Constructing a dual-band antenna for 40 and 20 meters often involves compromises in size or complexity. This resource presents a compact _open sleeve dipole_ design that addresses these challenges by using 450-ohm ladder line and folded elements to achieve a total length of approximately **17.17 meters**, significantly shorter than a full-size 40-meter dipole. The design leverages electromagnetic coupling, where a primary radiator handles the 40-meter band, and a second conductor resonates on 20 meters without direct electrical connection. This configuration eliminates the need for traditional traps, loading coils, or switching components, simplifying construction and reducing potential loss points. The antenna is fed with RG-58C/U coaxial cable, and a common-mode choke is recommended at the feed point to suppress sheath currents, ensuring a cleaner radiation pattern and minimizing RF in the shack. The design is well-suited for portable operations, field deployments, temporary installations, and restricted urban environments where space is a premium, offering solid performance on both HF bands.

This tutorial provides detailed instructions for constructing a DIY magnetic loop antenna, ideal for amateur radio operators seeking efficient short wave communication. The design features a remote tuning system utilizing an Arduino and RC servo, making it suitable for indoor use where larger antennas cannot be installed. Magnetic loop antennas are compact and can operate effectively in confined spaces, but they do require careful handling due to the high voltages and currents they generate during operation. Users should possess the necessary technical skills to implement this project safely. The tutorial includes a comprehensive overview of the antenna's theory, specifications, and mechanical design. It outlines the components needed, including a Soviet-made variable capacitor and a digital RC servo for tuning. Safety precautions are emphasized, as the antenna can produce several kilovolts of voltage and high currents. The project is not certified for safety, and users are advised to proceed at their own risk. The tutorial also provides diagrams and explanations of the antenna's operation, making it a valuable resource for both beginners and experienced operators looking to enhance their setup.

The VKFAQ page on Visitors' licences in VK outlines the process for foreign amateur radio operators to obtain reciprocal operating privileges in Australia. It details the varying requirements based on the visitor's home country, ranging from direct use of a home callsign with a VK suffix (e.g., G3PHO/VK1) to needing a full Australian amateur radio license. The resource emphasizes consulting the Australian Communications and Media Authority (ACMA) website for the most current conditions and application procedures, noting that agreements are subject to change. Specific conditions are mentioned for countries with recognized license qualifications, allowing for corresponding Australian licenses. For other countries, a restricted license might be issued, typically permitting 146-148 MHz FM operation with a maximum of 10 watts output. Japanese operators with specific 'telephone or telegraph' licenses may receive privileges for bands above 30 MHz, phone only, also with a 10-watt power limit. Visitor licenses are not automatically renewable but can be extended upon request, provided all conditions are met.

Accessing current operational statistics for a DXpedition is crucial for DXers planning their next contact. This Club Log page provides a detailed, real-time overview of the 3Y0J Bouvet Island operation, a highly sought-after DXCC entity. It presents a dynamic dashboard showing total QSOs, unique calls worked, and duplicate contacts, all updated as logs are uploaded from the remote location. Users can observe the expedition's progress and strategize their operating times. The interface features interactive charts and graphs, allowing operators to analyze the _3Y0J_ log data by band and mode, including CW, FT8, and SSB. A breakdown of QSOs by continent provides insight into propagation patterns and where the expedition has focused its efforts. The page also includes a map for checking real-time propagation conditions to Bouvet Island, which is invaluable for optimizing contact attempts. Further details include the first and last QSO times, total operating days, and the impact on users' DXCC totals, such as new bands, modes, or DXCC entities worked. This resource is a vital tool for the DX community, offering transparency and actionable intelligence for chasing one of the rarest entities on the air.

When planning your operating schedule, a reliable contest calendar is an essential tool for any serious contester. This DARC-maintained resource compiles current contest announcements for both HF and VHF/UHF operations, making it straightforward to identify upcoming opportunities for competitive radio sport. My own experience has shown that having a centralized, well-organized calendar saves significant time, especially when targeting specific events like the Clubmeisterschaft Classic (CMC) or the KW-Pokal. The DARC calendar highlights these German and European scoring contests in yellow, providing immediate visual cues for participants. HF contests are clearly marked in blue, while VHF/UHF events appear in red, simplifying band-specific planning. Beyond the major international contests, the calendar emphasizes regional events, which can be particularly useful for those aiming to improve their standing in local club competitions or explore less common contest formats. Special activity periods, such as those spanning multiple days, are also noted with a green background, ensuring operators are aware of extended operating windows.

The Intercontinental Amateur Traffic Net (Intercon) operates daily on 14.300 MHz, providing a platform for emergency communications and facilitating third-party traffic among amateur radio operators. Established in 1960, the net aims to foster goodwill and friendly relations within the ham community. It operates from 0700 to 1200 Eastern Time, with a focus on monitoring emergency traffic while encouraging operators to maintain a distance of at least 5 kHz to avoid interference. All licensed General Class operators and above are welcome to check in, using standard phonetics for clarity. The net features rotating Net Control Station (NCS) operators every hour, ensuring a diverse range of voices and experiences. Operators are encouraged to provide relays and assist with emergency traffic when necessary. While there is currently no membership for non-NCS operators, opportunities exist for those interested in becoming NCS operators. The net emphasizes professionalism and courtesy, making it a valuable resource for both emergency communications and casual check-ins.

This practical, hands-on article offers a valuable journey through balun construction for portable antenna systems. The author skillfully navigates from theoretical debates to practical implementation, providing a well-documented DIY process using RG316 micro coax and an FT114-43 toroid core. The step-by-step instructions, complemented by photographs, make this complex technical project accessible to hobbyists. Particularly impressive is the author's focus on lightweight design (just 173 grams) for SOTA field operations. While the final antenna requires minor tuning adjustments, the successful field test during the Pirate Contest demonstrates the effectiveness of this approach. An excellent resource that transforms theory into practical application for ham radio operators.

Over 100 FCC districts are analyzed by this resource, providing a predictive database for amateur radio vanity callsign assignments. The system simulates the FCC's application process, calculating the probability of assignment for specific callsigns, such as KD3Q at 94% or N9QC at 97.8%. Data is meticulously organized by FCC district, detailing available, pending, and upcoming callsigns, alongside those currently blocked by renewal or other FCC administrative actions. This allows hams to gauge their chances of securing a desired callsign. The database presents specific application entries, including the date entered, receipt date, process date, the applicant's current callsign, and the vanity callsigns they have applied for. Each entry facilitates examination of predicted outcomes, which categorize potential assignments as assigned, competitive, non-assigned, unneeded, curable, or unknown status. For instance, an application for K7DM clearly shows multiple applicants, indicating a highly competitive assignment scenario. This tool is particularly useful for those seeking a **short callsign** or a **1x2, 2x1, 2x2, 1x3, 2x3, 3x1, 3x2, or 3x3 callsign** that aligns with personal preferences or contest aspirations. It provides a clear, data-driven perspective on the likelihood of obtaining a specific vanity callsign.

Hamradio_copilot is an open-source tool designed for DXers and contesters who need real-time situational awareness. It is ideal for operators who want to visualize propagation trends instantly rather than scrolling through raw text streams of cluster spots. Rally acting as a copilot for your station, this tool transforms raw data into actionable intelligence. By visualizing Signal-to-Noise Ratios (SNR) across different bands, it helps operators make quick decisions on which band to prioritize or where to point their antennas, effectively showing not just who is on air, but where the propagation is currently open from your location. This is a fantastic information for avid contesters. The software aggregates data from two primary services: - Reverse Beacon Network (RBN) via Telnet. - PSK Reporter via MQTT feeds. It processes this data to generate a comprehensive HTML report featuring SNR heatmaps and statistical breakdowns by ITU Zone. Users can filter data by specific zones or country codes (ADIF), analyze historic time ranges, and optionally integrate solar weather data. The complete source code is available on GitHub, allowing for community customization. It is written in Python and uses SQLite for data management.

The Saturn PCB Toolkit is the best freeware resource for PCB-related calculations you can find. It incorporates many features that PCB designers and engineers are in regular need of like current capacity of a PCB trace, via current, differential pairs and much more. Please download our PCB Toolkit today for free and enjoy!

Beaches On The Air is an award scheme for radio amateurs that encourages portable operation from beaches. You can participate from any country or region around the world. Our beach lists currently contain more than 30,000 beaches and aim to be as exhaustive and objective as possible, and are often based on official sources, such as environmental protection agencies.

The Peilgruppe Neandertal, featured on Peilsport.de, actively promotes _Amateur Radio Direction Finding_ (ARDF), also known as fox hunting. This German group combines radio technology with outdoor sport, participating in regional and national ARDF events. Members access current ARDF schedules, competition results, and downloadable certificates directly from the site. The content highlights the adventurous spirit of ARDF, emphasizing the blend of technical skill and nature exploration. DL7ET and DR9P are noted callsigns associated with the group, indicating active participation from experienced operators. The site also covers related activities like Foxoring, a variation of ARDF that integrates orienteering with radio direction finding. This resource serves as a central hub for the Neandertal group's activities, documenting their involvement in a sport that challenges both physical endurance and radio proficiency.

Over 15 amateur radio bands, from 160m to 70cm, are supported by the _DXTRON_ web cluster, providing real-time DX spotting information. This service integrates directly with the _QRZCQ_ API, allowing users to monitor activity across various modes including CW, Phone, Digi, RTTY, SSTV, and SAT. DXTRON displays critical spot data such as timestamp, spotter callsign, frequency, mode, DX call, and remarks, along with geographical details like Grid, DXCC, ITU, CQ zone, continent, and country. Developed by _DO5SSB_, DXTRON v1.42 offers a user-friendly interface for filtering spots by band and mode, catering to both casual DXers and serious contesters. The platform is designed for accessibility, providing a clear overview of current propagation conditions and active stations worldwide. This web cluster is a practical tool for hams seeking to identify rare DX, track contest activity, or simply observe band conditions. Its reliance on the QRZCQ API ensures a consistent flow of up-to-date spotting data, making it a reliable resource for real-time operational awareness.

Eaton provides a comprehensive suite of power quality solutions, ranging from compact single-phase isolation units to high-capacity megawatt sag correction systems. The resource details Eaton's engineering expertise in addressing diverse power quality challenges, emphasizing the distinction between DC resistance and apparent AC resistance under heavy current loads within AC power distribution systems. Specific **Marine-Grade surge protective solutions (SPD)** are highlighted, designed to safeguard critical safety and navigation equipment on vessels and rigs against unpredictable power transients in harsh environmental conditions. The company's commitment extends to providing appropriate solutions for critical power systems, ensuring quality installation. The site also features customer testimonials from entities like Federal Express, Kutztown University, J. C. Penney, and Fairchild Aircraft, attesting to the effectiveness of products such as 'The Protector' in preventing equipment damage and downtime.

The resource details active HF radio networks maintained by foreign ministries for diplomatic communications, specifically listing operational schedules and frequencies. It currently covers networks for Bulgaria, Czechia, Egypt, North Korea, Russia, Tunisia, and the United States. The content provides specific operational parameters for these government-run shortwave stations. Information includes details on _legacy modes_ of operation and specific transmission times. The site also includes schedules for various _number stations_ which often utilize similar HF spectrum allocations. The data presented aids in identifying and monitoring these unique, non-amateur radio signals across the shortwave bands. Specific sections are dedicated to the networks of North Korea and the United States, offering granular data for each.

This page provides updated data and statistics about United States amateur radio operators, including historical totals, demographics, and geographic distributions. It also explains the Amateur Radio Service, highlighting its role in promoting wireless communication and technological advancements. The page is a valuable resource for hams interested in understanding the current landscape of amateur radio in the United States.

This page provides detailed information on the 4DX directional wire beam antenna designed by LZ1AQ, LZ1ABC, VK6LW, and DD5LP. It explains how to create this antenna for single or multiple bands using four separate sloping wires. The page includes instructions on achieving directionality, gains, and F/B ratios, as well as generating radiation patterns, VSWR charts, antenna currents diagrams, and Smith charts. It is a valuable resource for hams interested in building and optimizing their own directional wire beam antennas for improved performance and long-distance contacts.

Examines current amateur radio satellite operations as of May 2026, providing a practical overview for hams interested in making their first satellite QSOs. The resource differentiates between Low Earth Orbit (LEO) satellites, such as the _ISS_, SO-50, RS-44, FO-29, AO-7, and GreenCube, and the geostationary QO-100. It highlights the distinct operational requirements for each, noting that LEO birds necessitate real-time tracking, antenna rotation, and Doppler compensation. The article emphasizes the critical practice of listening before transmitting and outlines methods for monitoring QO-100 in real time via the Goonhilly Earth Station WebSDR. It also covers tracking LEO satellites using tools like N2YO.com, Heavens-Above, and amsat.org/status. The author's experience with these platforms informs the guidance on equipment considerations and operating practices, ensuring hams understand the nuances of satellite communication in 2026, including the significant impact of QO-100 since its 2019 launch.

Presents a dynamic platform for real-time amateur radio contest scoring, enabling participants and enthusiasts to monitor ongoing competition results. The system processes submitted contest data, displaying live scores and competitor standings as they update. Users can observe the progress of various contests, gaining immediate insight into the competitive landscape. This resource serves as a central hub for following _DX contests_ and other operating events, offering a transparent view of current standings. It facilitates an engaging experience by providing up-to-the-minute score updates, reflecting the intensity of _on-line contesting_ and the efforts of operators globally. The platform's utility extends to both active participants submitting scores and observers interested in the competitive dynamics. It aggregates data from multiple sources, presenting a consolidated view of contest activity. The system's design emphasizes rapid data processing and clear presentation of results, crucial for high-stakes events like the _CQ World Wide DX Contest_.

The Ukrainian Contest Club (UCC) website details contest activities, including a March 2026 contest calendar compiled by _UW3WF_ that excludes specific "exotic" tests, mini-tests, sprints, VHF competitions, and events organized by Russian entities. It lists major contests such as the ARRL International DX Contest, Stew Perry Topband Contest, and CQ WPX SSB Contest, providing dates, times, modes, bands (e.g., **10-160m**), organizers, log submission methods, and deadlines. The resource also highlights Ukrainian participation in various international contests, noting specific callsigns that represented the UCC, and acknowledges new Ukrainian records, such as UW5Y's new record in the ARRL DX CW Contest. The site presents contest results and rankings, including the top 20 Ukrainian contesters in the World Amateur Radio Contesting Association (WARCA) rating for 2019-2024, with _UW1M_ ranked #18 globally and #1 in Ukraine with **26,490.32** points. It also details the club's 12th place finish among 155 clubs worldwide in the CQ WPX Contest 2024 (CW + SSB). The resource includes information on WRTC 2026 participants from the club and lists members excluded due to collaboration with adversarial entities, reflecting the current geopolitical context.

OpenRTX is a free and open source firmware for digital ham radios. The firmware is designed with a top-down approach with the objectives of modularity, flexibility and high performance. Currently, it targets some Tytera Radioddity Baofeng digital radios

Well, firstly the 12 Volt source will typically vary anywhere from 11 Volt to 15 Volt, and then a battery needs a controlled charge current and voltage, which cannot result from connecting it directly to a voltage source.

Operating on the HF and VHF bands, the URE WebCluster serves as a real-time DX spotting network for amateur radio operators. It aggregates DX spots from various sources, presenting them with detailed information such as DX callsign, frequency, mode, and spotter details. The platform integrates essential propagation data, including current solar indices like _K-index_ and _A-index_, alongside visual propagation maps, which are crucial for planning long-distance contacts. Users can submit new DX spots, contributing to the collective intelligence of the amateur radio community, and filter existing spots by band, mode, or callsign, enhancing operational efficiency. This resource enables operators to monitor band openings and identify active DX stations, significantly aiding in _DXCC_ pursuit and contest operations. The integration of solar-terrestrial data directly within the cluster interface allows for immediate correlation between propagation conditions and observed DX activity, a feature not universally present in all web clusters. By providing both raw spot data and contextual propagation information, the URE WebCluster offers a practical tool for real-time decision-making during operating sessions, allowing hams to quickly adapt to changing band conditions and target specific _DX_ entities.

Online browser-based resource for your computer, tablet or other mobile device. Use this review and practice exam resource with the current editions of ARRL License Manuals.

In this study, the author builds upon Muncy's research, demonstrating that radio-frequency current on cable shields affects audio systems through the "pin 1 problem" and shield-current-induced noise (SCIN). An enhanced equivalent circuit for ferrite chokes is proposed, addressing dimensional resonance and inductor self-resonance. Field tests confirm that chokes reduce interference across 500 kHz to 1,000 MHz. Guidelines for diagnosing and mitigating EMI from various sources are provided for product development and field installations.

The Thevenin equivalent simplifies a complex circuit into an equivalent circuit with a voltage source and resistor for easy analysis of voltage and current at any point in the circuit. Use this online Thevenin calculator

AllScan is a free and open-source web app for AllStar nodes that provides Favorites Management features, AllStarLink Stats integration, and connection monitoring and control functions. Shows your favorites in a Dashboard summary table with Keyed status, Connected Node count and other statistics. Continually scans the status of each favorite using ASL's Stats API data showing which favorites are active and have recently been active. Allows favorites to be connected with a single click (optionally automatically disconnecting any currently connected nodes first). Allows the Favorites Table to be sorted by Node#, Name, Description, Location, etc. Favorites can be added/deleted simply by entering the node# and clicking a button. These features finally give AllStar nodes similar memory management and scan capabilities that analog radios have had for decades. AllScan is mobile-friendly and optimized for ease of use on both small and large screens. AllScan follows the latest web development standards, with PHP, JavaScript, HTML, and CSS cleanly partitioned, runs on both ASL and HamVOIP, and is very easy to install, configure, and update.

Detecting stray RF voltages on station grounds, chassis, and interconnecting cables is crucial for preventing program and hardware failures in the shack. This article details the construction and application of an LED RF V-probe, which offers significantly higher sensitivity compared to conventional neon lamp indicators. The probe leverages two specific properties of modern red LEDs: their ability to glow at microampere currents and their rectification capability at frequencies up to tens of megahertz. The design features a simple circuit with two LEDs, allowing for indication of both positive and negative RF voltage half-waves. The minimum detectable RF voltage is approximately 2 V, a substantial improvement over the 40-60 V threshold of neon bulbs. The resource illustrates the probe's physical construction on a PCB and provides a direct comparison demonstrating its superior sensitivity in detecting RF fields near a coil. Two operational modes are described: a non-contact mode for high RF voltages (above 15-20 V) and a direct-contact mode for measuring lower RF voltages, with a safety caution for the latter. Practical examples show the probe's use in analyzing RF voltage distribution across a radio station setup at 1.84 MHz and 24.9 MHz, revealing insights into common-mode current issues and the effectiveness of mitigation strategies like adding radials.

DF6QV's 4-Square antenna analysis begins with a two-element array simulation, demonstrating azimuth and elevation plots for various phase differences, including a 75-135 degree range. The document then delves into the core components of a 4-Square system, such as radiators, couplers, phasing lines, and ground systems, referencing W1HKK's 1965 QST article on an 80m phased array. It explores the influence of ground conditions and element spacing on antenna performance, presenting EZNEC analysis for an 80m 4-Square with an elevated radial, showing how gain and beamwidth vary with spacing. Various 90-degree couplers, including the 3 dB hybrid coupler and the Reed Fisher coupler, are analyzed using LTSpice, detailing power splitting, phasing, and bandwidth characteristics. The resource quantifies power, voltage, current, and losses within a 4-Square system, addressing relays, capacitors, inductors, radiator radial systems, and cable losses. System impedance, bandwidth, SWR, isolation, and mutual coupling are discussed with practical construction aspects covering common mode chokes, phasing boxes, and remote control systems. Field test observations for 40m 4-Square antennas are included, with specific examples from DXpedition operations like 5A7A and VP6DX, providing real-world context to the theoretical and simulated results.

The Zeppelin antenna, a J-type design, is presented as a two-band HF dipole, offering independent operation on harmonically related frequencies. This resource details its electrical configuration, comprising a half-wave radiator end-fed by a quarter-wave matching section, and explores its historical evolution from early Zeppelin airship applications to modern amateur radio use. The article specifically examines how a Zepp antenna tuned to 28.4 MHz (10 meters) exhibits a harmonic relationship with 15.4 MHz (20 meters), noting a frequency ratio of approximately 1.84:1, which deviates from a perfect 2:1 due to factors like elevation, wire separation, velocity factor, and end-effect. Antenna modeling results, including SWR sweeps at 28.4 MHz (1.1 SWR) and 15.4 MHz (1.6 SWR), are provided through Graph 1 and Graph 2, illustrating the antenna's performance across these bands. Current distribution patterns for both the 28.4 MHz (second harmonic) and 15.4 MHz (first harmonic) operations are visually represented in Figure 2 and Figure 3, respectively. The author also includes a 4NEC2 model's "Symbol Conversion file" definitions and calculated #14 wire dimensions for achieving resonance at 28.4 MHz, with the antenna positioned at a height of 33 feet. The discussion further highlights the antenna's versatility, suggesting its potential as a single-band, center-fed, 15.4 MHz half-wave folded end dipole when fed at a specific low current point. This analysis provides practical insights into constructing and optimizing a multi-band Zepp antenna for HF operations, emphasizing its unique harmonic characteristics and physical compactness.

The **5-Port 12 Volt DC Power Strip Kit (Rev 4)** offers a practical solution for managing shack power distribution, providing one input and five fused outputs. All connections utilize the ubiquitous Anderson PowerPole connectors, a standard for many amateur radio operators, ensuring a clean, organized, and safe way to power multiple 12 VDC transceivers and accessories from a single source. This design mitigates the common issue of tangled wires and overloaded connections in a typical ham shack. Rated for a maximum current of 20 Amps at 12 VDC, the strip incorporates an integrated LED to indicate when external power is applied. Each output is individually fused, a critical safety feature that protects connected equipment from overcurrent conditions without affecting other devices on the strip. This level of protection is essential for preserving sensitive radio gear during operation. Assembly requires basic soldering skills and hand tools, with a high-power soldering iron and wide chisel tip specifically recommended for best results. The kit's compact dimensions of 4.13" x 1.78" allow for flexible mounting via screw holes, making it suitable for various shack configurations and portable operations.

Callook provides a **USA amateur radio callsign lookup service** with data current as of March 25, 2026. The platform allows users to search for valid callsigns and retrieve detailed information, including geographic coordinates sourced from the Bing Maps API. A mathematically calculated **grid square** is derived from these coordinates, though accuracy is not guaranteed due to reliance on external services. The service supports multiple access methods, including a browser search plugin, direct API access with a reference, and plain text output for integration into other applications or scripts. This tool facilitates rapid identification of US amateur radio operators, offering an alternative to other callbook services. Its API access enables developers to integrate callsign lookup functionality into custom applications, streamlining data retrieval for logging software or contest management. The direct presentation of FCC data, combined with grid square calculation, assists DXers and contesters in verifying contact information and location details during on-air operations.

Demonstrates the design and modeling of a **160m** vertical antenna, dubbed the "WindoVert," specifically for urban amateur radio operators with limited space. The resource covers the theoretical underpinnings of antenna height and radiation patterns, using EZNEC software to analyze current distribution and 3D radiation patterns for various configurations, including a Marconi-style "T" antenna. It details the integration of existing antenna components, such as a Carolina Windom balun and line isolator, into the new vertical setup, and the practical measurement of feedpoint impedance using an antenna analyzer. The article further explores the challenges of achieving low-angle radiation on Top Band, emphasizing the critical role of radial systems and mitigating ground loss. Author VE1ZAC presents EZNEC models illustrating the impact of lumped components and discusses the practical considerations of resonant frequency adjustment and impedance matching for **QRP** operation. The text details the calculation of required loading coil inductance and capacitance, and shares field results, including successful DX contacts on 160m and unexpected excellent performance on 30m.

Accessing the official Estonian amateur radio call sign database is facilitated through this resource, which offers a direct search utility for **ERAU** registered licensees. Users can input a call sign to retrieve associated public information, ensuring accurate identification of Estonian stations. The system directly queries the national amateur radio society's records, providing real-time data on active **ES-prefix** operators. This utility is distinct from global callbook services, focusing exclusively on Estonian amateur radio operators. It serves as a primary source for verifying call sign authenticity and operator details within the country's regulatory framework. The interface is streamlined for quick lookups, making it efficient for DXers and contesters targeting Estonian entities. The resource's direct integration with the Estonian Radio Amateurs Union (ERAU) database ensures the presented information is current and authoritative, reflecting the latest licensing status and operator details for the amateur radio community.

Understanding how radio frequency interference (RFI) is coupled into equipment and subsequently detected is crucial for amateur radio operators. This guide delves into the fundamental mechanisms of RFI, particularly focusing on detection at semiconductor junctions and the unintended antenna action of system wiring. It explains that most RFI detection follows a square law, meaning a 6 dB reduction in RF signal can result in a 12 dB drop in detected audio, offering a practical approach to mitigation. The resource also clarifies the concept of common mode versus differential mode signals, detailing how cable imperfections can convert common mode antenna current into differential signals. It addresses the critical "Pin 1 Problem" in audio interfacing, a common design flaw where cable shields connect to the circuit board instead of the shielding enclosure, leading to significant RFI issues. Practical solutions, such as proper shielding, using twisted-pair cables, and strategic bonding of equipment, are discussed to effectively reduce or eliminate RFI. The guide emphasizes the importance of proper filtering and the often-misunderstood concept of "ground" in electrical systems, distinguishing between earth ground, equipment ground, and circuit common. It provides insights into minimizing loop area in wiring to reduce inductively coupled noise and antenna action, drawing on the author's extensive engineering background and ham radio experience.

A common mode choke/balun, essential for mitigating common mode current on antenna feedlines, is detailed in this construction and measurement guide. It utilizes eight Fair-Rite #2643167851 Mix 43 ferrites housed within a Hammond 1598JSGYPBK plastic case, with RG-8X coax cable forming the windings. The document references design principles from Ian White, GM3SEK's article on cost-effective ferrite chokes. Specific construction details include the layout of three coils to minimize inter-coil coupling and methods for securing the ferrites with foam tape. The resource presents comprehensive measured data, including isolation impedance (magnitude, real, and imaginary components), Q factor, inductance, and phase angle across various frequencies. It also covers the choke/balun's coax frequency response and return loss characteristics. Techniques for measuring choking impedance are thoroughly explained, focusing on S21 transmission measurements with a Vector Network Analyzer (VNA) and testing ferrite beads in both S11 and S21 modes. The guide describes a practical setup using an aluminum sheet or baking foil for measurements and outlines the calculation of series impedance from attenuation in a 50-ohm system. Additionally, it details a method for determining the balun's equivalent L and C around resonance by adding a parallel capacitor.

The Alfa Alfa (AA) DX Group, established on March 1, 1974, in the Netherlands, is presented as the pioneering Dutch 27mc DX group. It details the group's historical significance, particularly its revolutionary use of the '000' club callsign (19AA000) which influenced international 11-meter group callsign structures. The resource outlines the group's re-establishment in 2024, inviting new active CB operators and _Short Wave Listeners_ (SWL) to join its ranks, emphasizing a free worldwide membership model. Membership requirements are specified, focusing on active participation with an assigned AA callsign. The group provides QSL card management services, with options for direct QSL requests requiring **3 USD** and a Self-Addressed Envelope, or **4 USD** via PayPal for expenses. It also mentions upcoming initiatives like an _AA DX Contest_ and an award program, with sections for certificates and plaques currently under construction. The site also lists useful CB resources, including an 11M DX Cluster and an 11M Callsign Database, and provides contact information for the founder, 19AA001 Mr. Theo, and the Worldwide QSL Manager, 178AA001 Mr. Emil, based in Bulgaria.