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Design your VHF UHF Yagi antenna online, a JavaScript enhanced web page that implements the design of an antenna for 2m and 70cm bands. This page offers a streamlined experience for Yagi antenna design enthusiasts. It assumes prior knowledge of Yagi design principles, minimizing distractions with a user-friendly interface. Equipped with essential equations, it provides instant design feedback. Red font warnings indicate design limitations, ensuring practical results. Constraints include Gain (11.8-21.6 dBd) and Boom Length (2.2-39 wavelengths), with additional frequency-dependent restrictions noted in input fields.

The project details a DIY SWR/Wattmeter designed around an _Arduino Uno_ shield, providing capabilities to measure RF power from 2 to **200 watts** and Standing Wave Ratio (SWR) for HF amateur radio bands. This construction features a compact design, integrating the measurement circuitry directly onto a custom PCB that interfaces with the Arduino Uno microcontroller. Key components include a directional coupler for sensing forward and reflected power, precision rectifiers, and analog-to-digital conversion for processing RF signals. The Arduino firmware handles calibration, calculations, and displays the results on an integrated LCD, offering real-time feedback on antenna system performance. The design prioritizes simplicity for homebrewers. Performance specifications indicate accurate readings within the **2-200W** power range, suitable for typical QRP to medium-power HF operations. The project provides schematics and a basic overview of the software logic.

Over 30 distinct shortwave (SW) receiver models are reviewed, offering insights into their performance, features, and user experiences. These evaluations, contributed by readers of the Usenet newsgroup **Rec.radio.shortwave**, cover a wide array of portable and tabletop radios, including popular units like the Grundig YB-400, Sony ICF-SW77, and various Realistic DX series models. Each review details aspects such as frequency range, tuning steps, SSB functionality, antenna performance, and construction quality, often comparing them to other receivers or ham transceivers like the Icom 725. For instance, the Grundig YB-400 review highlights its 144-30000 kHz AM/SSB coverage, direct keypad entry, and 40 station memories, noting its useful narrow bandwidth and tone switch for adjacent signal separation. It also discusses the **SSB mode** stability and the limitations of its 1 kHz frequency resolution for precise zero-beating. The review further details antenna performance, including the effectiveness of the built-in whip, the provided 7m reel antenna, and the potential for overload with larger outdoor antennas. Other reviews delve into specific issues, such as the Sony ICF-SW77's frequency display inaccuracies and timer malfunctions, or the Realistic DX-342's compact size and surprisingly good MW DXing capabilities despite its analog tuning. The collection provides practical, user-generated feedback on sensitivity, selectivity, audio quality, and ergonomic features, helping shortwave listeners understand the real-world performance and quirks of these receivers.

Dchematics and photos of a secure power supply (short-cut, Rf feedback, high voltage etc.) by iz7ath

Demonstrates an online **CW** audio decoder tool, currently under active development, designed for analyzing and decoding Morse code. Users can upload audio files containing Morse code or record live audio input via a microphone, with processing handled entirely in JavaScript using the Web Audio API. The software analyzes the audio, attempting to determine the pitch and speed, and then decodes the message, providing options to compare the decoded output against a predefined message or a perfectly timed version. The interface allows for setting optional comparison messages, character speed in WPM, and Farnsworth speed. It also features interactive charts for visualizing the audio analysis, where users can zoom with the mouse wheel and pan by dragging. Specific buttons highlight different element types such as intra-character space, inter-character space, extra elements, missing elements, and replaced elements, aiding in detailed signal analysis. Built-in test files are available for immediate analysis, allowing users to quickly evaluate the decoder's performance. The tool is noted to work with specific browsers and is presented as a testing platform for user feedback, indicating ongoing refinement of its decoding algorithms and user interface.

HotPaw MorseDecoder, an iOS application, provides real-time translation of Morse Code audio signals into plain text, leveraging the device's microphone or headset input. It incorporates a DSP narrow-band audio filter, adjustable from 300 to 2400 Hz, to mitigate background noise and QRM, enhancing signal clarity for decoding. The application offers both an automatic decoding mode and manual controls for fine-tuning parameters such as audio filter frequency, WPM dot/dash speed, noise threshold, and Farnsworth timing. The WPM detection automatically adapts from 8 to 40 WPM, with a QRQ High Speed mode extending this range to 30-80 WPM for faster code. A built-in spectrogram aids in identifying the precise audio frequency of the CW tones. User feedback indicates effective performance with various transceivers like the Yaesu FT-857 and Icom IC-R8600, particularly when manual settings are optimized. The app's ability to visually tune stations within the passband and decode speeds beyond an operator's manual capability has proven beneficial during contests and general QRP operation.

For amateur radio operators running Microsoft Windows XP or later, Lux-Log provides a robust logging and contest software solution, designed by Norbert Oberweis, LX1NO. It is capable of managing over 30,000 logbooks within a single database and image copy, offering comprehensive data handling features. The software facilitates data import and export via **ASCII** and **ADIF** formats, ensuring compatibility with other logging applications, and includes an integrated tool for converting data from other programs into ADIF. It provides instant feedback on previous contacts and country information during data entry, alongside static or serial value generation for contesters. Lux-Log integrates a versatile award module, currently supporting 123 definitions for popular awards such as DXCC, WAZ, WAS, US Counties, IOTA, and more. Operators can generate pre-defined and user-definable data queries, visualize statistics through bar/pie charts, and print QSL labels. The software also interfaces with the RAC Callbook and HamQTH, supports LoTW, and offers radio control for Icom and Yaesu FT-857 transceivers. Additionally, it supports telnet connections to internet clusters and integrates with K1EL's WinKey for CW generation, making it a comprehensive tool for both general logging and contesting activities.

In this article K3DAV show a very simple way to make an RF choke coil that will remove your RF feedback troubles

Call Book Log 3.0 is a web-based logging solution for amateur radio operators, designed for self-hosting on a web server with MySQL/MariaDB and PHP 7+ support. It provides a mobile-friendly interface for viewing, adding, editing, deleting, backing up, and restoring QSO logs. The software features a streamlined setup process, allowing users to quickly deploy a personal logging system accessible via any web browser. Key functionalities include displaying the last **5** contact dates for previously worked stations, enhancing log management by providing immediate historical context during QSO entry. The system also includes a central administrative section for authenticated users to manage log entries. The 3.0 version represents a significant code overhaul, focusing on improved performance and a more *visually appealing* user experience compared to earlier iterations. Enhancements include better pagination, a redesigned menu with icons, and color-changing rows for improved readability. The add log page now incorporates a one-click time update feature, addressing user feedback regarding time synchronization during rapid QSO entry. This iteration builds upon previous versions like 2.1, which corrected an automatic _UTC date_ bug, and 2.0, which featured a full rewrite to resolve browser quirks and optimize search functions. The software's evolution demonstrates a commitment to functional stability and user interface refinement.

Demonstrating the construction of a short dipole antenna tailored for the 60 meter band, this resource provides detailed instructions for radio enthusiasts with limited space. The design incorporates inductive loading using two inductors (L1/L2) made from PVC tubes, allowing for effective operation on 5 MHz. The antenna consists of 12 meters of wire, divided into four sections, with specific dimensions and materials outlined for optimal performance. Results from users indicate that this antenna can significantly enhance DXing capabilities on the 60 meter band. Feedback from operators suggests that while the design is effective, adjustments may be necessary based on individual setups, such as coil diameter and wire gauge. Many users report successful construction and operation, with some experimenting with variations to improve resonance. The practical application of this antenna design has led to successful contacts and improved signal quality, making it a popular choice among 60 meter band operators.

Operating a ham station often involves encountering radio frequency interference (RFI), RF feedback, or RF burns, which are frequently misattributed to poor equipment grounding. This resource meticulously dissects these assumptions, asserting that RF grounds on the operating desk often merely mask more significant system flaws. It identifies five primary causes for RF problems, including antenna system design flaws, proximity of the antenna to the operating position, DC power supply ground loops, equipment design defects, and poorly installed connectors or defective cables. The content emphasizes that issues like "hot cabinets" or changes in SWR when connecting a ground indicate substantial RF flowing over wiring or cabinets, a phenomenon known as common-mode current. The article provides detailed explanations of common-mode current generation, particularly from single-wire fed antennas like longwires, random wires, and OCF dipoles, which inherently present high levels of RF in the shack. It also illustrates how vertical antennas, lacking a perfect ground system, can excite feed lines with significant common-mode current. Through simulations, the author demonstrates how a dipole without a proper _balun_ can cause RF problems at the operating desk, showing current patterns and voltage distributions on feed line shields. The discussion extends to the proper application of _RF isolators_ and _ferrite beads_, clarifying their role in modifying common-mode impedance on cable shields and cautioning against their use as a band-aid for fundamental system defects. The resource advocates for correcting the actual source of RF problems, such as antenna system issues or poor connector mounting, rather than relying on internal shack grounding or isolators. It highlights that properly functioning two-conductor feed lines, like coaxial or open-wire lines, should result in minimal RF levels at the operating position, even without a desk RF ground. The author shares personal experience, noting that his stations since the late 1970s have operated without RF grounds at the desks, relying instead on proper antenna system design and feed line integrity.

Constructing a digital interface for the Elecraft K2 transceiver, this resource details the "Fat Wire" design by WG4S. It demonstrates how to integrate a sound card for digital modes, outlining specific connections to the K2's microphone jack and internal audio path. The author shares practical insights from his build, including the use of _RG-62_ coax for its flexible braid and the strategic placement of components like the 2.2K resistor and _2N2222_ transistor. The guide provides a breakdown of the interface's internal wiring, specifying connections for AF In (pin 1), AF Out (pin 5), PTT (pin 2), and Ground (pin 7) on the K2's microphone connector. It also covers the external connections to a laptop's headphone and line-in jacks, along with a DB-9 connector for PTT control via _DTR_ or RTS lines. The author notes that his laptop's headphone output level was sufficient for the K2, negating the need for an attenuator. Reflecting on the design, the author, Dan WG4S, acknowledges a later suggestion to house the components directly within the DB-9 shell for a more compact build. This iterative feedback highlights the ongoing evolution of DIY ham radio projects and the community's collaborative spirit in refining designs.

The Kenwood MC60A with preamp, suffers from RF feedback, a search on the web reveals the extent of the problem. This document explain how to fix this problem.

The RBN S-Meter visualizes real-time HF propagation data from the Reverse Beacon Network (RBN). It processes thousands of automated spots per hour, providing a real-time picture of active RF paths on HF bands. Users can set their vantage point using _Region Mode_ or _Grid Square Mode_. Region Mode allows selection from broad geographic areas like E. North America or Europe, while Grid Square Mode uses a Maidenhead grid square and radius for more precise data. The app displays eight region panels, each with horizontal bars for bands 160m through 6m, indicating signal strength with a color ramp from green to red. A dimmer trail shows peak hold values, and an S-unit readout provides additional detail. The app is a free web application accessible on any device, offering a practical tool for ham radio operators interested in CW, RTTY, and FT8 signals. It features a Progressive Web App installation option for enhanced usability on mobile and desktop platforms. Users can install it on Android, iOS, and Windows devices, providing a native app-like experience. The app replaces the previous Windows standalone executable, incorporating user feedback to improve features like grid square mode and automatic location detection.

256 memories enable the _AT-AUTO_ to recall settings across multiple bands, making it efficient for operators who frequently change frequencies. The tuner is compatible with various antennas and amplifiers, such as the Mercury LUX, and integrates seamlessly with radios like the FLEX 6400 using an RS232-USB connection. This integration allows the tuner to follow frequency changes without additional input, enhancing operational efficiency. Despite being out of production, the _AT-AUTO_ remains supported by Kessler Engineering, which offers firmware updates and repair services. The tuner features a cross-needle SWR meter, providing quick visual feedback during tuning. It also includes a QRO keyline circuit to protect amplifiers during tuning. Users appreciate the tuner's ability to track radios via CAT control, avoiding automatic tuning during QSOs, a common issue with other models. The _AT-AUTO_ is praised for its durability and performance, with many users noting its reliability over years of use. Its ability to handle legal limit power and its balanced line output make it a versatile choice for serious operators. Although it lacks some features like multiple coax outputs found in other models, its robust build and continued support make it a valuable tool for HF enthusiasts.

Learn how to build a simple 12vdc azimuth and elevation motor unit for the Arrow Satellite Antenna to improve your FM satellite communication experience. This DIY project involves using a camera tripod and basic materials like aluminum tube and standoffs. Get detailed instructions, including the gearhead motor product number for optimal performance. Discover where to purchase the necessary components and stay updated on alternative motor options. Enhance your ham radio operations with this homemade rotator setup, designed for easy satellite tracking and communication. Share feedback and connect with other radio enthusiasts for more tips and ideas.

The **Nilex Morse Tutor** is an HTML5 web application designed to teach Morse code reception, adapting to user proficiency by adding new characters as readiness is detected. It prioritizes practice on less familiar letters, numbers, symbols, words, and phrases, while minimizing repetition of already mastered elements. The program offers multiple learning orders, including "Q7ZG..." (Ward/Jim's), "KMRS..." (PU5EPX/Koch), "KMUR..." (lcwo.net), "AENT..." (CWops CW Academy), "TEAN..." (Stephen C Phillips), "ANET..." (Vic VE3YT), and "ETI5..." (Ham Whisperer), alongside an alphabetical option. Users can customize the learning experience by enabling or disabling automatic progression, and selecting specific content categories such as numbers, symbols, words, phrases, QSO bits, Ham Radio Bands, X+Y=Z math, and units. Audio settings are adjustable for volume, speed (WPM), tone frequency, and keyshape/keying envelope, allowing for a personalized auditory environment. The interface provides visual feedback with blue bars indicating practice emphasis and gray bars for reserved characters, with clickable bars for manual character selection. Developed by "Nosey" Nick Waterman, VA3NNW, this tutor is based on earlier versions by Jim Wilson and a 1977 QST article. A significant October 2019 rewrite incorporated a new WebAudio sound library by AwesomeAidenW, improving offline functionality and mobile support. The content library was expanded to include 3000 top Google words, 2284+ General Service List words, ISO country codes, capital cities, US states, Canadian provinces, UK counties, common names, periodic table elements, quotes, Q-codes, electronic components, ham abbreviations, and example call signs. The software is distributed under the GNU GPL V2 license.

The Score Distributor facilitates real-time score forwarding for amateur radio contests, automatically transmitting data from various logging software to multiple online scoreboards. By configuring logging applications to send score data to the Distributor, operators ensure their current score is simultaneously represented on platforms like the _Contest Online ScoreBoard_ (COSB) and the Live Contest Score Server by R4WW. This system eliminates the need to choose a single scoreboard, providing broader visibility for participants. This utility enhances the competitive experience by allowing contesters to monitor their performance against other stations throughout an event. Observing real-time standings can provide significant motivation, particularly during periods of challenging propagation or when striving to maintain pace with club members or peers. The platform supports almost all major contest logging software, simplifying integration for a wide range of operators. Developed by WA7BNM, the Score Distributor was last revised on June 14, 2023. It aggregates score data, offering a unified point of submission that then disseminates the information, ensuring a **single point of entry** for broad scoreboard coverage and improving the dynamic feedback loop for participants.

This online tool is a specialized web-based utility for orchestrating multi-operator HF contest and DXpedition activities. This tool, _Rig2Cast_, assists station managers in meticulously planning operator shifts, ensuring adequate rest periods, and crucially, preventing operational conflicts such as assigning a single operator to multiple radios concurrently. It integrates support for SO2R operations and offers real-time simulation of operator requirements, a feature I've found invaluable in pre-event planning. The scheduling engine incorporates five distinct algorithms: greedy fairness balancing, round robin, maximum coverage, simulated annealing, and a fatigue-aware model. These algorithms enforce critical constraints like minimum/maximum shift durations and mandatory rest times across all radios, which directly impacts operator performance over long events. My field experience confirms that such robust constraint management is essential for maintaining peak efficiency during intense operations. Key features include distributed multi-station support, printable per-operator cards, flexible band activity windows, and real-time editable operator slots. The drag-and-drop shift management, coupled with full cross-radio swap support and smart constraint feedback (valid targets in green, invalid in red), streamlines complex scheduling tasks. The system's design ensures user data privacy, as no information is stored on the server; schedules are saved and reloaded locally.

The ICOM IC-R75, introduced in 1999, operates on 13.6 Volts DC and measures 241 by 94 by 229 mm. Its coverage spans from 30 kHz to 60 MHz, making it a versatile receiver for various bands. The review details available accessories, including optional filters and the **UT-106 DSP module**, which significantly enhances signal processing capabilities. Performance comparisons are drawn against other notable receivers such as the Drake R8B and earlier ICOM models, providing context for its audio quality and overall functionality. User feedback is integrated, offering practical insights into its daily operation and reception characteristics across the spectrum. This analysis offers an in-depth look at the IC-R75's technical capabilities and features, serving as a valuable reference for operators interested in this **legacy receiver**.

AA9PW offers free practice exams for all three US license classes plus international licenses like Canadian and Australian. The site generates random tests from the current question pools, simulating the actual exam experience. You can choose between online exams or printable PDF versions for offline study. The site maintains a simple, no-frills interface that loads quickly even on slow connections. Practice tests provide immediate feedback with score reports highlighting areas needing improvement.

This page provides a detailed comparison between the Zero Five and Gap Titan ham radio antennas. The author shares their personal experience with both antennas, highlighting pros and cons for each. They discuss aspects such as ease of assembly, customer service, tuning capabilities, performance on different bands, and the need for grounding and tuning. The comparison aims to help readers make an informed decision on choosing the best antenna for their needs, based on real-world usage scenarios and feedback.

Demonstrates the construction of an active loop converter specifically designed for the Low Frequency (LF) bands, addressing common localized noise interference in LF reception. The design integrates a sharply tuned circuit and a tuned loop antenna, utilizing the loop as the sole tuned inductive element. By applying positive feedback, the converter significantly increases the loop's effective Q, achieving factors between 1000 and 2000, which sharpens tuning and reduces noise. The circuit employs an _NE602_ mixer stage, feeding its output to an HF receiver, with a crystal-locked local oscillator at 4 MHz. A 20-turn, 0.8-meter square loop antenna with 500 uH inductance is detailed, connected via 2 meters of figure 8 flex cable. The converter offers three selectable frequency bands: 195-490 kHz, 150-220 kHz (including the New Zealand amateur band), and 128-160 kHz (covering the European amateur band). Performance measurements indicate an effective 3dB bandwidth of approximately 100 to 200 hertz at 200 kHz. The article provides insights into component selection, including an _LF353_ op-amp and a trifilar wound transformer on a ferrite core. Sensitivity figures are presented, showing 7.5 uV of converted output per 1 uV/meter signal strength into a 50-ohm load, or 37.5 uV into an _FRG7_ receiver, highlighting its capability to extract weak signals from noise.