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This DIY guide details constructing a 5-element Yagi antenna for VHF frequencies. Yagi antennas offer directional signal transmission/reception compared to omnidirectional ones. The guide covers material selection (aluminum, screws, etc.), design using software or formulas, and step-by-step assembly including cutting elements, drilling holes, and attaching the coaxial cable. While calculations are provided for a 146 MHz design, adjustments are necessary for different frequencies. Safety precautions and potential result variations are emphasized.

In a quest for reliable emergency power, the article discusses the necessity of accessible power solutions amidst blackouts and energy crises. It introduces the American-made Merlin Panther 100-watt solar briefcase and budget-friendly LiFePO4 batteries. The setup addresses the need for modular, renewable power solutions, balancing cost-effectiveness with functionality for various scenarios. The narrative emphasizes the importance of reliable power sources in unpredictable situations.

The article describes how to build a 12V emergency power supply for amateur radio stations. Starting with a basic jump-start system, the author upgraded it using a Group 27 deep-cycle battery and a 45W photovoltaic solar system, adding connectors and outputs for various devices. The system is portable, affordable (under $100), and capable of powering a station for 20 hours. The author emphasizes keeping batteries charged with a float charger and offers assistance to fellow club members interested in building their own power supply.

A home made project for a 7 element yagi antenna for the two meters band based on the DK7ZB original desing.

An **Arduino LC Meter** provides an accessible solution for precisely measuring inductance and capacitance values, crucial for RF circuit design, filter tuning, and troubleshooting in amateur radio applications. This project details the construction of a low-cost, accurate instrument using readily available components, making it an attractive alternative to commercial units for hams and electronics enthusiasts. The build process involves assembling a resonant circuit, integrating an Arduino microcontroller for frequency measurement, and displaying results on an LCD. Key components include an Arduino Uno, a 16x2 LCD, a 74HC14 Schmitt trigger inverter, and a few passive components. The design leverages the Arduino's processing power to calculate L and C values from resonant frequency shifts. Calibration procedures are outlined to ensure measurement accuracy, which is vital for critical RF work. The project includes schematics, a parts list, and the necessary Arduino code, enabling hams to construct a functional LC meter for their workbench.

This project details the design and construction of a Spider Quad antenna for HF bands (20m, 17m, 15m, 12m, and 10m). The boomless structure optimizes driver and reflector spacing, enhancing performance. Tuning and impedance matching were refined using antenna analyzers and a 1:2 balun. Final tests confirmed excellent SWR and gain, making this an efficient solution for top performance DXing.

This page provides construction details for a 4-element 10-meter Yagi antenna with 28 Ohm impedance. It includes information on the elements, positions, diagrams, and data related to frequency, gain, front-to-rear ratio, radiation resistance, SWR, and loss. The content is aimed at hams or radio operators interested in building and optimizing Yagi antennas for the 10-meter band.

This is a plan for an optimized element UHF Yagi Antenna for UHF Bands featuring a 9dBd forward gain, a 13 dB front-back ratio, and a bandwith of 10 MHz on the 430-440MHz range.

Method, Units of Measure, and the Dipole Standard of Reference. This article helps in understanding where does beam gain come from in directional aerials like in example Yagi antennas.

This page delves into the debate surrounding the End-Fed Half-Wave (EFHW) antenna, exploring whether it is truly a multiband antenna without the need for a tuner. The author investigates the claims and criticisms surrounding these popular antennas, discussing their resonance on various bands and their efficiency for DXCC achievements. The content is valuable for hams interested in understanding the capabilities of EFHW antennas and their performance across different HF bands, with a focus on practical usage and real-world results.

With increased ES propagation, this lightweight 5-element LFA antenna offers enhanced performance over the Bigwheel antenna's 5dBi gain, delivering approximately 11dBi and forward gain. Designed from G0KSC’s specifications, the 1.8m antenna was adapted for reduced weight using 6mm and 4mm rods instead of heavier tubes. 3D-printed PETG clamps ensure durability and precision, while the first tests showed excellent SWR and element coupling. Though built with a temporary Choke BalUn, the results were promising, with a Pawsey Stub BalUn planned next for further optimization.

Inspired by Heathkit, author aimed to enhance his Yaesu FT-817 with audio and RF processing. Design goals included a compact enclosure, PCB simplicity, matching jacks, a visual meter, and a built-in signal generator. Despite challenges in finding a suitable compressor IC for a 5V DC mic jack, he chose the Analog Devices SSM2165/2166 series. Prototyping with a solderless breadboard, author planned a PCB layout for its versatile performance in communication use.

An information paper by the International Amateur Radio Union. The amateur service seeks the return to an exclusive, worldwide allocation of no less than 300 kHz in the vicinity of 7 MHz.

Wavelog, a web-based amateur radio logbook application, launched in February 2024, represents a significant fork from the established Cloudlog platform, developed by a core team including DF2ET and DJ7NT. This open-source project focuses on delivering advancements in both stability and functionality, specifically tailored for the amateur radio community. The application allows users to manage their radio logs from diverse environments, including professional servers, standard web hosting, or even compact _Raspberry Pi_ setups. The platform distinguishes itself through its emphasis on simplicity, robust features, and versatile accessibility, enabling operators to log contacts from virtually any location. It supports various operating modes and data formats, providing a flexible solution for tracking QSOs and managing station activities. The project's development is driven by the collaborative spirit of the amateur radio community, prioritizing utility and user experience over commercial objectives. Key features include comprehensive logging capabilities, support for multiple bands and modes, and integration with common amateur radio data standards, ensuring broad utility for DXers and contesters.

Approximately 100 MeshCom nodes are visualized in real-time on a geographical map, providing a dynamic overview of the LoRa mesh network. This resource, hosted by _OE1KFR_, details node positions, telemetry data, and message traffic. Users can measure distances between two selected nodes, view text messages with callsign, destination, and gateway information, and access position data including latitude, longitude, and altitude. The platform supports filtering by regions such as Europe, USA, and Asia, allowing operators to focus on specific geographical areas. The detailed node list table presents comprehensive status information for each node, including gateway callsign, firmware version, hardware type, and environmental telemetry like temperature, pressure, humidity, and CO2 levels. This granular data enables operators to monitor network health and individual node performance, facilitating troubleshooting and optimization of MeshCom deployments. The map interface enhances situational awareness for those engaged in LoRa mesh networking.

Four _Headway 38120_ LiFePO4 cells form the core of an 8AH 12V battery pack, designed for reliable emergency and field power in amateur radio operations. These batteries offer significant advantages over traditional lead-acid types, including a lifespan up to **10x** longer in charge/discharge cycles, lower internal resistance for faster recharging, and a flatter discharge curve that maintains voltage stability during use. Their inherent safety, being a flame-retardant technology, makes them a preferred choice for portable applications. Proper configuration, including parallel/serial setups, and careful charging/discharging protocols are crucial for maximizing battery life. Each cell has a nominal voltage of 3.2 volts, with a maximum charge voltage of 3.65 volts. A Battery Management System (BMS) is highly recommended to prevent overcharging or deep discharging, safeguarding the cells. The project emphasizes safety, noting the batteries' high short-circuit capacity of **200 AMPS** and the critical importance of incorporating an inline fuse between the battery pack and the load. Components like the battery holder, buss bars, and a suitable case are also detailed.

This article provides a cost-effective and reliable method for fixing antenna elements in the traverse of HF/UHF Uda-Yaga antennas. It outlines a step-by-step process using soft galvanized steel wire, eliminating the need for special adapters or additional holes. The method described ensures a secure attachment without compromising the mechanical strength of the traverse, offering a durable solution for ham radio operators constructing antennas. The use of galvanized steel wire guarantees long-lasting stability, making it a practical and efficient technique for antenna assembly.

Inrad Roofing Filter installation instruction, The IC-775 Roofing Filter Mod consists of a 6 pole, 5 kHz wide filter followed by a high dynamic range, feedback amplifier.

Details the construction of a portable 6-meter 4-element quad antenna, specifically designed for VHF and Field Day operations. The design emphasizes portability and rapid field assembly, utilizing a 10-foot boom, #12 bare wire elements, and fiberglass electric fence post spreaders. It presents specific dimensions for reflector, driven element, and directors, including spreader lengths, circumferences, and corner marks, all derived from a G0KSC design and modeled in EZNEC. The resource outlines the fabrication of synthetic lumber hubs that allow post-assembly adjustments along the boom, and describes spreader clamps made from ¾” OD fiberglass rod, drilled and tapped for 8-32 nylon thumbscrews to secure element wires. It provides instructions for reducing spreader ends to 0.370” OD for proper fit and details the assembly of the boom from two 1½” OD x 6’ aluminum tubes. Performance data from EZNEC modeling indicates a gain of 10.25 dBi (8.1 dBd) and a 20 dB F/B ratio at 50.150 MHz, with SWR values of 1.08, 1.09, and 1.11 at 50, 50.15, and 50.5 MHz respectively. The document includes a field test report from Field Day 2010, where the antenna was deployed at 21 feet, showing an SWR resonance 200 KHz below EZNEC predictions. It notes successful 5-watt QSOs into New York and Canada from Tennessee, highlighting the antenna's excellent directivity and gain compared to a 4 dBd Moxon. The antenna breaks down into easily transportable components, including two 5’ boom sections, a 3’ boom connector, 16 spreaders, and four element/spreader clamp assemblies.

This page offers the latest version of SIMPLEX, a freeware program designed for hams to create and manage radio repeaters. Compatible with Windows XP and higher, in 32 & 64-bits, SIMPLEX supports English and French languages. Linux/Ubuntu/Android users can use WINE 1.0 or CROSSOVER to run the program. SIMPLEX allows the creation of simplex, duplex, transponder, and mixed repeaters, with features like survey functions and time/weather beacons. The package includes a DTMF encoder for testing codes. Suitable for ham radio operators looking to set up and manage their repeater systems.

This page discusses the construction and design of a shortened 2-element Yagi antenna for the 40-meter band, focusing on the driven element. The author shares insights on adding hats to the coil to reduce losses and improve performance. The article also mentions the use of EZNEC modeling software and an AIM4170 analyzer for tuning. Amateur radio operators interested in such antenna design and optimization for the 40-meter band can find useful information and practical tips on this page.

Paul McMahon details the design and construction of a four-element Yagi antenna for the 50-52.5 MHz range, published in Amateur Radio Magazine (Dec 2011). The antenna, featuring a raised driven element and a capacitive/DC connection using copper strips, maintains consistent VSWR and performance despite two years of weather exposure. The design utilizes inexpensive plumbing conduit for the boom and provides detailed construction guidelines, parts lists, and performance analysis through 4NEC2 simulations.

A detailed guide presents a simple 2-element quad antenna for 2m, offering ease of construction, portability, and efficient performance across the 144-148 MHz band. The design allows quick disassembly for storage and features adjustable polarization, making it ideal for various applications, including transmitter hunting and SSB operations.

This article discusses the design and implementation of a 2-element wire beam antenna for the 20 meter band, suitable for field day operations with 4 Switchable Directions. The antenna is configured with sloped wires in an inverted V shape, with a specific design to achieve directional properties. The author tested the antenna design using MMANA and NEC2 software, based on a solution published in QST. Detailed diagrams and instructions are provided for constructing the antenna on top of a 12 meter mast, with specific wire lengths and positioning to ensure optimal performance. This resource is valuable for hams looking to build a directional antenna for the 20m band and improve their field day setup.

The UV-K5 HF Fullband receive firmware version 0.3 introduces enhanced SSB capabilities using the SI4732-A10 chip. Released separately from UV-K5 CEC firmware, it offers improved HF reception, mode changes, frequency fine-tuning, and user modifications. New PCB designs and detailed usage instructions are included.

Demonstrates the capabilities of DXtreme Monitor Log 14, a specialized software application designed for radio spectrum monitoring and logging. The resource details its core functionality, which includes logging stations across various bands and supporting multiple transmission modes such as AM, CW, FM, LSB, USB, and RTTY. It highlights features like the ability to select country formats for new databases and the **Schedule Checker** tool, which assists users in identifying broadcast stations for monitoring. The software facilitates tracking **Maidenhead grid squares**, particularly useful for VHF and UHF monitoring activities. It also supports QSL management and offers tools for efficient contact logging, catering to both amateur radio operators and shortwave listeners. Specific information includes its version number, Monitor Log 14, and its utility for DXers and other radio enthusiasts in managing their monitoring experiences and logging contacts effectively.

The FT101ZD DDS VFO project replaces the original VFO in the Yaesu FT101Z/ZD rigs with an AD9850 DDS module, providing enhanced frequency control. It uses the original optical encoder and clarifier for compatibility, with a custom 6V power supply modification. The project includes selectable step sizes, a frequency save function, and works with both RX and TX modes. The design involves mechanical and electronic modifications, including SMD components and a custom PIC processor. Calibration ensures accurate frequency output, with further improvements under consideration.

The 2m 7 element Yagi antenna is a perfect beam antenna with 11dB gain and a front-to-back ratio of 20-25 dB. It has seven elements and requires a matching network built of 3/8" aluminum tubing and RG-8 cable. The gamma tube is adjusted to provide the best fit, and the gamma-driven element feeding clamp is tightened. If the beam is vertical, a non-conducting mast is utilized to prevent detuning and skewing of the radiation pattern. For optimal VHF operating, the antenna is installed at a height of 30 feet or higher.

SunCalc is a tool that displays the movement of the sun and sunlight phases for a specific day and location. Users can adjust the sun's positions for sunrise, selected time, and sunset. The visual representation includes a curve showing the sun's trajectory and variations throughout the year. The tool also provides information on sunlight distribution during the day. SunCalc is useful for hams wanting to plan outdoor activities based on sunlight availability and position. Users can support the website's maintenance with a donation via PayPal.

Testing of real antennas is fundamental to antenna theory. The most common and desired measurements are the antenna radiation pattern including antenna gain and efficiency, the impedance or VSWR, the bandwidth, and the polarization. The procedures and equipment used in antenna measurements are described in this page.

In this project by building a W2IMU feed horn, the author successfully optimized their 10GHz Small Dish EME project. To position and solder the components together, they used a jig and a conical section made of copper sheet. Stability was ensured by fitting the XLNA to the WG switch. The WG components were shod into a waterproof plastic container, and the feed horn and WG were surrounded by a collar and skirt that were 3D printed. With an average Moon noise of 0.5dB, the Sun and Moon noise readings were better than their previous configuration.

When installing a mobile antenna, optimal placement significantly impacts performance. Factors such as gain, antenna type, ground plane availability, mounting style, and environment must be considered. Antenna designs, such as 1/4 wave and 5/8 wave, have distinct radiation patterns ideal for specific settings—urban areas or flat terrains, respectively. Ground plane size requirements differ by frequency, impacting effectiveness. Among vehicle mounting options, the car roof center provides the best ground plane and minimal obstruction, ensuring peak performance, especially at higher frequencies like 800 MHz.

A small Yagi antenna for camper van. It is made of aluminum tubing, breaks down for storage, and works well for communicating with others. He built it in an afternoon and it gets good signal. The antenna is lightweight and can be packed up to fit inside his van while traveling

This article from the July 1976 issue of Radio REF discusses the trend of large antennas for ham radio operators on the low bands. It specifically focuses on a Yagi 2 element antenna for the 80m band, detailing its construction and functionality. The author explains how the antenna can be switched between directing signals towards the West or East using a switch at the station. The article also provides technical details on the lengths of the director and reflector elements, and how they impact the antenna's performance. A useful resource for hams looking to build or understand Yagi antennas for the 80m band.

Operating on the 60m band requires specialized antennas, and the 2 Element HB9CV, also known as the _ZL special_, excels in this domain. With a gain of **7.3 dBi** when phased at a 162-degree shift, it rivals traditional 3-element Yagi antennas, making it a solid option for enhancing 60m operations. The construction process is thoroughly detailed, providing insights into its performance and practical applications. Real-world comparisons demonstrate that the HB9CV antenna outperforms long Beverage antennas by an average of **5.5 dB** in reception, showcasing its effectiveness in various conditions. Insights from Mr. Cebik's analysis further validate its design, confirming its capability to maximize communication on the 60m band.

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.

Guide to constructing an effective antenna for 50MHz. Inspired by a design from Martin DK7ZB, the article emphasizes the importance of precise measurements and quality materials. With a 2.20m boom and careful assembly, the antenna promises excellent performance, resilience, and cost-effectiveness, making it ideal for six meter band operations.

Presents the design and construction of a folding 5-element Yagi antenna specifically engineered for 144 MHz portable operation, particularly for VHF contest Rover categories. It details element dimensions, boom construction using ¾-inch pine, and a folding mechanism that reduces the 52-inch boom to 26 inches for transport. The document provides a table with precise element distances and lengths, including a 2.4 mm length correction for solid parasitic elements, and specifies the use of 3/16-inch solid aluminum for parasitic elements and brass tubing for the driven element. It also covers the bent dipole driven element design for impedance matching, balun implementation with Type 31 ferrite beads for common mode current suppression, and weatherproofing for the feed point. The resource includes predicted performance data from 4NEC2 modeling, showing SWR and return loss characteristics, as well as gain and front-to-back ratios at various frequencies across the 2-meter band. It reports a measured SWR of 1.2:1 at 144.2 MHz and 1.5:1 at 147 MHz, corrected for 25 feet of RG-8/M coaxial cable loss. The design offers approximately 1.5 dB more gain than a previous 4-element design, maintaining a decent SWR up to 147 MHz, and was successfully deployed in a winning June 2016 ARRL VHF Contest Rover entry.

Examines the historical context of amateur radio, specifically focusing on Guglielmo Marconi's pioneering wireless transatlantic signal reception at Signal Hill, Newfoundland, in 1901. It describes the operation of a contemporary remote radio station at Signal Hill, utilizing the special event call sign _VD1M_ issued by Innovation, Science and Economic Development Canada. The content recounts a specific contact from Signal Hill, reporting a signal strength of 5 by 9 to a station in Sarnia, Ontario, which received the signal at 3 by 3. The narrative also introduces the concept of 'Marconi chasers' who endeavor to replicate historical transmission methods. Further, the resource discusses general amateur radio operating procedures, the evolution of the hobby, and its critical role in emergency communications, citing examples from hurricanes _Irma_ and _Maria_ in 2017 and the conflict in Ukraine in 2022.

This resource provides an in-depth look at Earth-Moon-Earth (EME) operating techniques specifically for the 432 MHz band and above. It outlines the differences in operational procedures between the 144 MHz and 432 MHz bands, emphasizing the importance of sequence lengths and scheduling. The initial calling period typically starts on the hour, with the eastern-most station calling first, which is crucial for effective communication. The document also discusses the challenges faced by operators, such as signal readability and the necessity of confirming exchanges. It highlights the significance of using a standardized procedure to enhance the likelihood of successful contacts. Additionally, it covers the use of signal reports and the importance of patience and clarity in communication, especially when dealing with weak signals. Overall, this guide serves as a valuable resource for amateur radio operators interested in improving their EME operations.

This guide by F4ANN (2014) explains replacing the backup battery in a YAESU FT-757 GX when stored frequencies reset on power-up. The original CR-1/3N lithium cell (3V, 160 mA) can be substituted with a CR2032 (170 mA), which is cheaper, widely available, and easier to replace. The process involves opening the transceiver, carefully desoldering the old battery from the PCB, and wiring in a holder for the CR2032. Extra care is required with screws, connectors, and soldering. The author also replaced backlights and serviced the cooling fan. Future battery replacements are simplified to four screws.

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.

Our Article about the ICOM IC-7760 announce done by ICOM at the annual Ham Fair in Tokyo

This project describes a high-performance EME antenna array consisting of two home-designed 9-element Yagis, each about 2.5 wavelengths long, combined into a 25-ohm system and matched to 100 ohms using 9/4λ sections of 50-ohm coax. The array supports rotatable polarity from 0° to 180°, allowing both horizontal and vertical polarization to optimize moonbounce performance under varying conditions. Despite operating for years without a balun—something another designer called “disastrous”—the system has delivered strong results, including copying very weak DX such as VK3KH at about -25 dB with only 120 W (around 2 kW ERP). The builder continues to refine the mechanics, having installed new gear motors and an upgraded follow-up control system in 2011.

Explore the pivotal role of artificial intelligence in advancing emerging radio technologies, facilitating ubiquitous connectivity essential for sustainable development, the digital economy, and the Internet of Things, guided by ITU's harmonized regulations and standards.

Constructing a 4:1 Guanella current balun involves cross-connecting two 1:1 current baluns. At the low-impedance end, transmission lines from each balun are connected in parallel, while at the high-impedance end, they are connected in series. This configuration allows the device to achieve a 1:4 impedance ratio, effectively transforming a 200-ohm load to 50 ohms. The balun described utilizes **FT240-43 toroids** wound with 2.5mm2 twisted pair cable for 8 turns, intended for use with a 20m **Deltaloop antenna**. Measurements performed with a 200-ohm resistor demonstrate satisfactory VSWR and impedance characteristics across the HF bands. The article compares the performance of 2.5mm2 cable versus 1mm enameled wire, recommending the former for superior efficiency. Emphasis is placed on maintaining short core-terminal connections to optimize performance. Additional considerations include the option of integrating a separate Common Mode Choke (CMC) for enhanced common mode current suppression, especially if the balun's inherent suppression is not prioritized.

This resource presents a non-rigorous evaluation of the front-to-back (F/B) ratio of short Beverage antennas, specifically designed for low-band operation on frequencies such as 160, 80, 40, and 30 meters. The author, VE1ZAC, details the methodology used to measure the F/B ratio, which involves using a Millen Grid Dip Oscillator as a portable signal source. Measurements were taken by switching the antenna direction and recording S Meter and preamp readings to derive gain numbers. The document discusses the challenges faced in achieving accurate measurements and the assumptions made during the process, such as the calibration of S Meter units at 6 dB. This evaluation is particularly relevant for amateur radio operators interested in antenna performance on low bands.

Demonstrates the construction of a portable 2-meter repeater system utilizing a **Yaesu DR-1X** transceiver, configured for both analog FM and C4FM digital voice operation. The design emphasizes portability, robustness, and effective thermal management, incorporating a "wind tunnel" airflow system with a fan to maintain transmit module temperatures at 38 degrees Celsius during continuous operation. The system integrates a diplexer, control head, and is housed in a compact, lightweight case weighing under 8kg, designed for single-person deployment. Covers practical considerations for field deployment, including power sources, antenna types, and the overall system architecture for public service events and emergency preparedness. The resource details the modular "wrap around" construction, showing how components like thermal switches for fan control and Anderson Powerpole connectors are integrated. It highlights the system's ability to provide reliable communications support for club activities and emergency communications.

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 WSJT Log Viewer, version 1.0.0.10 as of 2026-08-02, is a freeware Windows application developed by Carsten Groen (OZ9AAR) for analyzing signal strengths from WSJT digital mode contacts. It processes the ALL.TXT log file generated by WSJT-X, extracting and presenting data from decoded TX and RX messages. Initially designed for EME operations on 70cm and 23cm, the software has expanded to include all HF bands, 6m, 4m, 2m, 1.25m, 70cm, 23cm, 24GHz, and 47GHz. Key features include displaying total QSOs, unique callsigns, days with activity, and signals heard, with filtering options by band and completed QSOs. The application also monitors the ALL.TXT file for live updates every two seconds, reflecting new decodes in real-time. Users can view session logs, activity charts showing daily signal counts and decoded signals, and a "Top Partners" tab listing the 25 most frequent contacts. The software provides detailed QSO information, including best received SNR and sent reports, with graphical representations of SNR over time. It supports multiple "My Callsign" entries within a single ALL.TXT file and offers a function to generate a text list of initials worked per band. The program is distributed as a single executable file, requiring no installation, and stores its configuration in a LogViewer.cfg file, allowing for different setups via command-line arguments.