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Examines Teledyne Cable Solutions' offerings, focusing on their engineered solutions for demanding cable applications. The resource details their capabilities in designing and manufacturing _multi-core cable_ and ruggedized assemblies, emphasizing their integrated approach within Teledyne Marine. It covers the technical aspects of their products, which are tailored to specific operational environments and performance requirements, ensuring reliability in challenging situations. The content highlights the practical application of their cable solutions across various industries, including those requiring robust interconnectivity for remote sensing or communication systems. It implicitly suggests how these specialized cables, designed for high performance and durability, could benefit amateur radio operators seeking reliable feedlines or control cables in extreme weather or portable operations, potentially offering superior signal integrity and mechanical strength compared to standard offerings. The company's focus on custom solutions distinguishes its approach.

Formed in 2010 by a group of hams whose core hobby interest is DXing and Contesting. The 599 DX Association members are unapologetic about their love and enthusiasm for this aspect of our hobby.

A Lightweight 2m Yagi for SOTA. The boom is 20mm PVC electrical conduit and the elements are 2.4mm aluminium TIG welding rod. The antenna is carried as a single length of conduit with the elements stowed inside the boom, sealing them in with a bung. The driven element is connected directly to 50 Ohm coax with a BN-43-202 balun core to decouple the coax shield.

Utilizing snap-on ferrite cores and practical insights, the author enhances their shack's cleanliness against electromagnetic interference. With meticulous experimentation and installation, they improve noise levels across HF bands, reflecting on the effectiveness of their filter in minimizing common-mode disturbances. Updates underscore ongoing refinement and cautionary advice for optimal filtering and radio reception amid changing RF environments.

Ferrite-shop is an on-line shop for ferrite toroids, cable cores and cable clamps based in The Netherlands

Explains the fundamental purpose of a repeater, detailing how these automated relay stations overcome distance and terrain limitations for VHF/UHF communications. It traces the historical development from early Bell Telephone Labs "relay" stations in 1922 to Art Gentry, W6MEP's, pioneering K6MYK amateur radio repeater in the mid-1950s, which remains active today. The resource clarifies the distinction between simplex and duplex operation, including the unique function of a "parrot repeater" for single-frequency recording and playback. Delving into the internal workings, the guide breaks down a repeater into its core components: the antenna system, feedline (often _Heliax_ or hardline for minimal loss), duplexer, receiver, transmitter, and controller. It emphasizes the critical role of the duplexer in preventing receiver desensitization by isolating transmit and receive signals, even with distinct frequencies. The discussion highlights the importance of high-performance, durable antennas and low-loss feedlines, citing examples of equipment installed in the 1960s and 1970s that are still in perfect working order. Operating a repeater is also covered, with an explanation of frequency offset (e.g., the 600 kHz standard for 2 meters) and the function of _CTCSS_ (PL tone) for access. It outlines standard input/output offsets for various bands, from 6 meters to 23 centimeters, while noting regional variations. The guide also touches on features like autopatch and Digital Voice Recorders (DVRs), providing a solid foundation for understanding repeater technology and usage.

HamAward is a cloud based amateur radio logbook allowing multi operators multi station activities, featuring real time cloud logging with live score counters. This online tool is addressed to support multi station award operations and management.

This blog post details the construction and usage of a 4:1 current balun, using two FT240-31 ferrite cores and 12 bifilar turns. It clarifies common misconceptions about using 4:1 baluns with G5RV antennas and ladder-line to coaxial cable connections. M0PZT emphasizes the importance of proper measurements and the limitations of internal baluns in manual antenna tuners. Detailed instructions and considerations for winding and deploying the balun are provided, along with advice on choosing suitable cores and wire for various power levels and frequency ranges.

Operating within the low-frequency spectrum, transformers serve critical roles in antenna systems, particularly for 160m applications. The resource details the construction and performance of 1:1 transformers built on BN-73-202 cores, emphasizing their use as hybrid combiners or phase inverters for RX antenna arrays. Measurements reveal that these transformers exhibit minimal losses, around 0.12 dB at 1.8 MHz, with variations based on wire type and number of turns. The analysis includes comparative data on transformer performance, highlighting the impact of different winding techniques on frequency response. Notably, the use of coaxial cable for winding improves bandwidth while maintaining low-frequency efficiency. The resource also discusses braid breaker transformers, which minimize inter-winding capacitance, achieving low losses around 0.21 dB at 1.8 MHz. These insights are crucial for optimizing low-band antenna systems, allowing operators to make informed decisions regarding transformer design and implementation.

This air-core solenoid style RF inductor calculator calculates the inductance, wire size, number of turns, and other parameters for an air-core solenoid inductor used in radio frequency (RF) circuits, based on user input of frequency, desired inductance value, and physical dimensions.

There are quite a few recipes for building a suitable transformer for an end fed half wave antenna (EFHW), but I was never sure I really understood the main principles. So, I wound a bunch of transformers, made measurements on them using my NanoVNA, learned how to get what I really wanted out of the VNA measurements, and in the process discovered how to build better transformers and be able to predict what they will do

This project uses an inexpensive Teensy microcontroller as the core of a flexible interface that provides a high-fidelity sound card and VOX functions for controlling the radio.The interface firmware supports variable VOX delay, CW and RTTY keying via audio (such as is available from Fldigi), and RTS and DTR control of any keying function, all via a single USB connection to the PC.

Professional Lithium-ion battery packs factory in Shenzhen China with more than 11 years experience in Battery business. Manufactured of Lithium ion and lithium polymer battery and Lithium battery packs.

Visualizes real-time amateur radio propagation spots using data from the PSK Reporter MQTT stream, providing immediate situational awareness for radio operators. The platform displays spots from various modes, including CW, WSPR, and JT65, in addition to the dominant FT8 digital protocol. FT8 Live focuses exclusively on live data streams, prioritizing current signal activity over historical archiving, which differentiates it from the official PSK Reporter map. A key feature is its integration with the Summits on the Air (SOTA) API, facilitating SOTA chasing by cross-referencing transmitting callsigns with SOTA alerts; a station is identified as an activator if the spot correlates with a scheduled alert within an eight-hour window. The user interface was developed by Arron (ZL1AN), with core data from Philip Gladstone (N1DQ), and stream delivery managed by Tom Stanton (M0LTE).

WSJTX-Controller-v2, or Otto, functions as an assistant for the WSJT-X amateur radio program, specifically designed to enhance operational efficiency for weak signal digital modes. The software automates several key tasks, including call management, prioritizing DX stations based on user-defined criteria, and optimizing frequency selection within the WSJT-X interface. It requires a modified version of WSJT-X to function correctly, integrating directly with its core processes to provide augmented control. Otto supports various digital modes, facilitating auto-logging of contacts and generating specific alerts for desired stations or conditions. It is engineered to streamline the workflow for operators engaged in DXing and general weak signal communication, offering features like automatic CQ responses and intelligent band monitoring. The utility is not compatible with certain other amateur radio software and is explicitly noted as unsuitable for contest operations or the WSJT-X Hound mode, indicating its specialized focus on non-contest DX and casual operating. The project's GitHub repository provides the source code and documentation, allowing users to review its implementation and contribute to its development. The software's design emphasizes automation to reduce operator intervention during routine digital mode operations.

The U01 emergency communications antenna is a versatile, multiband antenna designed for 80/60/40/20/17/15/10m bands, known for its reliability and compact size. It features a broadband transformer wound on various core options like FT82-43, FT114-43, or FT140-43, with the latter capable of handling up to 100W. The antenna incorporates a PCB with options for SMA and BNC connectors, and a weather-proofed design for durability. The lightweight construction, using materials like DX Wire UL and Polyester rope, makes it highly portable. The antenna's design has been tested and proven within the DARC Chapter U01, with multiple build options and detailed documentation available for DIY enthusiasts.

The UniBalun is a PCB for building a lightweight antenna transformer (Balun) or impedance converter (UnUn) for low power radios. By soldering jumpers and a toroid core, you can create a 1:1, 1:4 Balun or 1:49, 1:9 UnUn. The latest revision (1.2) includes improved pads and supports both BNC and SMA connectors. Build instructions are available for German speakers.

1-watt 17-meter cw transmitter that was originally done about 10 years ago as a club project for RAMS, the Radio Amateur Megacycle Society. It uses a VXO, rather novel at the time. It also uses a bandpass filter at the output rather than the usual lowpass

KlaTrack is a Windows-based software application designed to assist amateur radio operators with satellite communication by predicting spacecraft visibility. It provides a simple interface to determine when specific satellites will be above the local horizon, a critical factor for successful two-way contacts via amateur radio satellites. The program processes _Two-Line Element_ (TLE) data to calculate orbital mechanics, offering a practical tool for satellite operators to plan their operating windows. It supports real-time tracking and displays essential pass information. This utility simplifies the complex task of satellite tracking, allowing operators to focus on making contacts rather than manual orbital calculations. While specific gain figures or distances are not quantified, the software's core function directly supports achieving successful satellite QSOs by providing precise pass predictions. It is particularly useful for operators engaging in activities like working the International Space Station (ISS) or other low-Earth orbit (LEO) satellites, where short pass times and precise timing are crucial for maximizing contact opportunities.

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.

Signal Stuff operates as an online retail outlet specializing in amateur radio antennas and related accessories, with a core mission to financially support educational platforms like HamStudy.org and ExamTools.org. The product line prominently features their Super-Elastic Signal Stick™ antennas, available with SMA-F, SMA-M, and BNC connectors, designed for various handheld transceivers including Baofeng, Icom, Yaesu, and Kenwood models. The site details product specifications, pricing, and a lifetime warranty for the Signal Stick™ antennas, emphasizing their role in funding free ham radio licensing study guides and exam administration software. Proceeds from antenna sales directly contribute to the development and maintenance of HamStudy.org, a free online resource for amateur radio license preparation, and ExamTools.org, software utilized by Volunteer Examiner (VE) teams for efficient exam administration. The site also promotes HamBook.org, a free series of comprehensive study guides, which integrates with the HamStudy app and website through links and QR codes for an adaptive learning experience. This business model links product sales to community support, providing essential tools for aspiring and upgrading amateur radio operators.

Manufactures Flyback, Switching, Audio, Toroidal, Current Sense & Custom Trasformer, Drumcore & PFC Inductor, Common Mode Chokes.

ARTIC is a specialized software tool designed for amateur radio operators participating in VHF contests, offering log checking functionalities. It specifically caters to Italian and Swiss VHF contests, such as the IAC (Italy) and SWAC (Switzerland), ensuring adherence to contest rules and accurate score calculation. The software is developed by IK2FTB and provides a dedicated platform for post-contest log analysis. This resource includes download links for various versions of the ARTIC software, with updates noted for different contest years and rule sets. For instance, versions like ARTIC 2022 and ARTIC 2023 are available, reflecting ongoing development and adaptation to evolving contest parameters. The page also features links to related contest resources and information, providing a centralized hub for VHF contesters to manage their logs and verify their entries.

A reproduction test of a a binocular ferrite core and winds a total of 7 turns is a patented rf choke with an unusual winding, although this winding scheme reduces the inductance, it might result in a much larger bandwidth over which the choke has a sufficiently large impedance. The Author test this model by reproducing the choke.

This PDF article introduces a series of dual-tuned bandpass filters designed for input tuning in amateur band receivers. Developed by Stefen Niewiadomski, these filters feature 50-ohm input/output impedance and can be cascaded for improved roll-off outside the passband. The designs use readily available TOKO coils, with taps on the tuned winding for matching input circuits with impedances around 1k ohm. The inductors are core-tuned, with average inductance values provided for easier matching to other inductors.

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.

The article describes the construction of a 1:49 impedance transformer designed to match the high impedance (around 2500Ω) of an end-fed half-wave (EFHW) dipole antenna to the 50Ω impedance of a typical transceiver. The EFHW is a popular portable antenna due to its simple construction, but feeding it can be challenging compared to a center-fed dipole. The transformer was built using an FT240-43 ferrite toroid core, with 2 primary and 14 secondary windings for a 1:49 impedance ratio. A capacitor was added in series with the primary winding to improve performance at higher frequencies. The author compared versions with one and two cores, and found that 100pF worked best for the single core design while 200pF was optimal for the dual core transformer.

Pro Audio Engineering (PAE) supplies products for broadcast and amateur radio applications. The company manufactures heatsinks for _Elecraft_ **KX2** and **KX3** transceivers. PAE also produces AC power supplies for HF transceivers, remote power relays, and Ethernet relays. Machined products from PAE are manufactured in the **USA**. PAE distributes _Fair-Rite_ Mix 31 ferrite snap-it cores and toroid cores in various internal diameters. The product inventory includes commercial monitoring antennas, UQUI transformers, ULP AC power filters, and 3M conductive adhesive copper tape. Offerings also include the AM1 Portable Antenna Mount System. Pro Audio Group, LLC holds the copyright for the company as of 2024 DXZone Focus: _Elecraft_ | _Fair-Rite_ | Heatsinks | Ferrite Cores

The Lakeway Amateur Radio Club, identified by its callsign _W2IQ_, serves as a significant hub for amateur radio operations within the Lakeway Area. This organization demonstrates a strong commitment to regulatory compliance and amateur radio accessibility through its robust Volunteer Examination (VE) Team. As an ARRL-accredited entity, W2IQ facilitates online FCC amateur radio licensing examinations, providing a critical service for new licensees to enter the hobby. This infrastructure supports the growth of the amateur radio community by streamlining the licensing process, making it highly accessible to prospective operators. The club's technical contributions extend to fostering diverse operational interests, though specific repeater or APRS infrastructure details are not explicitly detailed. Their emphasis on licensing and education, particularly through remote testing protocols, highlights a modern approach to amateur radio entry. This focus on **VEC protocol coordination** ensures a consistent pathway for individuals seeking to obtain or upgrade their amateur radio licenses. The club also promotes engagement with various aspects of the hobby, indicating a broad interest in amateur radio activities and technical development within its geographic sphere of influence. Their dedication to supporting new radio amateurs underscores a foundational role in regional frequency management and community building.

A tiny board, which allows a smartphone or similiar device to connect to the Baofeng UV5R radio via a TRRS audio connector. It allows for connecting the radio to a software TNC app such as APRSDroid or PocketPacket. Solder on the components, solder on the cables, then provide some stress relief, (I use solid-core wire and heat shrink tubing), and you can use your UV5R with your smartphone for APRS on the cheap.

Presents a detailed construction guide for a 9 dB, 70cm collinear antenna, utilizing readily available _RG58/U_ coaxial cable and PVC pipe for housing. The resource outlines the critical calculations for ½ wavelength sections at 444 MHz, incorporating the coaxial cable's velocity factor of 0.66, which yields a section length of 223 millimeters. It specifies the preparation and soldering of eight such half-wavelength sections, each cut to 231mm to allow for trimming, forming the core of the array. Further instructions detail the integration of a ¼ wave element (169mm #16 solid wire) at the top and a ¼ wave aluminum tube (160mm, 5/16 inch) at the bottom, crimped to the feed point's braid. The guide also addresses RF common mode current suppression by suggesting the use of _FT50-43_ toroids on the feedline. Final assembly steps cover mounting the antenna within ¾" PVC pipe using a wooden dowel, waterproofing connections, and initial SWR checks. The article also discusses scaling the design for different element counts and other VHF/UHF bands.

This comprehensive three-part guide examines baluns (balanced-to-unbalanced devices) and their critical role in ham radio antenna systems. The author explains how baluns prevent common-mode currents on feedlines, which can distort radiation patterns and cause unwanted RF in the shack. Various balun types are analyzed, including coiled coax chokes, ferrite-core designs (W2DU), and toroidal-wound versions (Guanella/Ruthroff). Construction techniques for 1:1, 4:1, 6:1, and 9:1 current baluns are provided with practical guidance on wire selection, winding methods, and ferrite core properties. The article emphasizes that proper balun implementation is essential for optimal antenna performance, especially with directional arrays.

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 document provides a detailed modification guide for the Zetagi HP201 SWR Wattmeter, converting it for HF amateur band usage. It replaces the original circuit with a Tandem Coupler based on the Sontheimer and Frederick directional coupler patent, enhancing accuracy and sensitivity. Key components include Murata toroid cores, scaling resistors, and a new calibration process. Challenges and solutions during the modification process are discussed, ensuring linear results across 160-10m bands. This guide also includes calibration instructions and theoretical insights into the coupler's operation.

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 page provides information about building a Beverage antenna for hams. The article discusses using a 60m wire on the ground to create an effective antenna for amateur radio operators. Learn how to set up and optimize this type of antenna for better reception and communication. This describes a low-noise receiving Beverage antenna setup for low bands, using a N30 cup core transformer for 1:4 impedance matching (likely 50:200 Ohm), RG-58 feedline with heavy common-mode choking, and conduit for wire burial.

Chokes and isolation transformers are essential for receiving antennas to mitigate common mode current, which induces noise and interferes with signal quality. Common mode chokes, formed by winding feedline through ferrite cores, block unwanted current effectively. Proper selection of core material and winding turns ensures resonance near the operating frequency, reducing interference. Isolation transformers further minimize interference, crucial for multi-transmitter stations.

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.

The Portable EFHW antenna for the 40, 20, 15, and 10-meter bands utilizes a broadband transformer with a 1:49 ratio, designed on a PCB by either Jan or DL2MAN. The design incorporates an **FT114 core**, offering an alternative to the FT82 core. The antenna requires precisely 20.5 meters of DX Wire Ultralight for optimal performance. Additional components include DX Wires "Dyneema" 1mm rope and 1mm bricklayers string for structural support. The SWR plot indicates performance at two elevation heights: 5.5 meters (blue line) and 4 meters (yellow line), demonstrating optimization for low-elevation portable use without poles. The antenna's components, including spool and rope tensioners, are available for 3D printing, with spool dimensions scaled to 130% for a length of approximately 110mm. The design emphasizes simplicity and portability, suitable for field deployment.

Analyzes the operational dynamics of the _IARU R1 VHF contest_, the world's largest 2-meter contest, focusing on factors enabling top performers to maintain consistent results amidst declining overall activity. The resource investigates the physical constraints that limit higher point totals, examining how technical capabilities, increased interference, and evolving station setups contribute to contest outcomes. It provides insights into the strategic and technical aspects of achieving high scores, such as the **1,000,000+ point** totals observed from leading stations. Compares the performance of various stations over time, highlighting the sustained success of top contenders and speculating on future trends in VHF contesting. The analysis delves into specific operational strategies and equipment choices that differentiate high-scoring stations, offering a detailed look at the competitive landscape. It also considers the impact of propagation conditions and operator skill on final scores, providing a comprehensive overview of the contest's intricate mechanics and the pursuit of maximum QSO points.

The new beginner tutorials for GNU Radio guide users through essential concepts, from installation to creating custom blocks. Topics include flowgraph fundamentals, DSP blocks, and SDR hardware integration. Intermediate and advanced sections cover core mechanics, modulation techniques, and developing out-of-tree modules, fostering a comprehensive understanding of signal processing.

Demonstrates the _Widget DX HB9HBY_ software, a compact desktop application for amateur radio operators, providing essential real-time information. The widget displays UTC time, current HF propagation conditions, local weather, and thunderstorm risk. It also integrates radio-related links and offers advanced PRO functions, such as a DX map, HF noise radar, IBP beacon synchronization, contest heatmap, aurora radar, and a rare DX radar. The software is available for Windows 10/11 and Linux, with a macOS version planned for future release, and supports both French and English interfaces. Author HB9HBY highlights the widget's simple installation process and automatic update capabilities, which can be silent for minor fixes or include notifications for significant changes. The free version provides core functionalities, while a 15-day free trial unlocks the PRO features. A lifetime PRO license is available for a one-time payment of CHF 10, activating advanced tools that help operators make quicker decisions at the station by correlating propagation, UTC, DX activity, and local conditions, though results remain indicative and require confirmation via listening or tools like _RBN_ or _PSKReporter_.

The article by Guy Olinger, K2AV, published in the May/June 2012 National Contest Journal, introduces the Folded Counterpoise (FCP), a compact 516-foot single-wire counterpoise elevated at 8 feet, designed for 160-meter operations on small lots like 100x150-foot backyards. Originating from efforts to revive Top Band for W0UCE on a postage-stamp property, the FCP uses strategic folds to cancel ground fields within 33 feet of center, minimizing losses to 0.13-0.53 dB—outperforming sparse or on-ground radials by up to 15 dB in poor soil—while mimicking opposed radials for efficient feedpoint impedance. Paired with a critical 1:1 or 4:1 isolation transformer (e.g., trifilar on T300-2 toroid) to block common-mode currents on coax feeds, it delivers proven results: K2AV's #8 North America low-power contest score, 7+ dB gains at W4KAZ and K5AF, and over 10,000 global web hits for DIY instructions using bare 12 AWG wire and weatherproof enclosures. Ideal for acreage-challenged hams, the FCP also excels on 80 meters with scaled dimensions, offering a low-loss alternative where full radials are impractical

Online impedance calculators grouped by types like Wire inductances, Toroid incuctances, Plane, PAD, Strap inductances, but even Core and Coax Inductances. Air core inductances and mutual inductance groups are also availbale. All these calculators let you input specific paramenters based on the inductor selected and will calculate specific incutance and related dimensions.

W1JR-style common mode chokes are versatile tools for antenna experimentation. Three variants were constructed using RK4 ferrite cores and RG303 Teflon coax, differing only in output terminals: banana connectors for dipoles, N-connectors for antennas with existing terminals, and bolts with washers for vertical antennas. Materials included junction boxes, terminals, and small hardware. Assembly involves maximizing windings on the core, securing with ties, and gluing components. Improvements included switching to multi-stranded wire for durability. These chokes provide efficient, customizable solutions for various antenna setups.

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.

Demonstrates a **Progressive Web App** (PWA) approach to amateur radio logging, providing a platform-agnostic solution for hams. The resource details its core functionality, including offline callsign and reference lookups, auto-formatting for data entry, and integration with **POTA spots** and saved re-spots. It highlights support for various logging templates such as General, Contest, POTA, and Field Day, indicating its adaptability for different operating activities. The application emphasizes seamless log synchronization across multiple devices, eliminating the need for manual file transfers. It operates effectively both online and offline, with installation options available for full offline functionality on Windows, Android, iOS, macOS, and Linux, or direct use within any web browser. The documentation further outlines features like rig control and the continuous development of additional templates, positioning Smart Logger as a flexible and efficient tool for managing amateur radio contacts.

This project involved designing a 7-pole Chebychev broadcast band filter to address severe interference issues caused by a new horizontal loop antenna on the KN-Q7A transceiver. The interference overwhelmed the transceiver’s front end, so a custom filter with a 3.5 MHz cutoff was built using silver mica capacitors and type 6 T130 toroidal cores. Encased in a diecast box with SO239 sockets, the filter blocks strong signals from the broadcast band, achieving over 100 dB attenuation. Tested up to 100W, it reduces interference effectively while maintaining low insertion loss across HF bands.

Demonstrates practical **rules of thumb** for selecting and utilizing ferrites and coils in amateur radio projects, particularly for RF applications up to 30 MHz. It addresses common challenges like determining appropriate ferrite grades and estimating L/C values without precise specifications. The resource details the author's experience with readily available grey ferrites, noting their suitability for HF work, and provides guidance on constructing **baluns** and RF chokes, balancing inductance for lower frequencies against inter-wire capacitance for higher frequencies. It also outlines a method for estimating power handling based on ferrite weight, suggesting a 1-gram ferrite can manage over 2 Watts, and offers a technique for evaluating unknown ferrites by winding 10 turns and measuring resonance with a 1 nF capacitor. This approach emphasizes a hands-on, iterative method for balun winding and adjustment, allowing operators to quickly approximate component values. The article compares the characteristics of ferrite-cored coils with air-cored coils, highlighting the reduced pickup and radiation of ferrite designs. It refines the air-coil estimation method for frequencies between 2.5 MHz and 10 MHz and provides a scaling factor for frequencies outside this range, aiming to get operators into the correct general area for their designs. The author's standardized ferrite choice (RND Components 165-00182) is presented as a practical example for reproducible projects.

This article investigates SSB signal quality during the CQ WW 2015 SSB contest. It highlights the importance of adhering to the ideal SSB signal profile, the impacts of intermodulation distortion, and the consequences of poor-quality signals. The analysis underscores the need for well-tuned equipment to ensure cleaner, more efficient signals and, consequently, a more enjoyable and spacious experience for contest participants and amateur radio operators.