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OpenHamClock is a modern, open-source dashboard for amateur radio operators, designed as a web-based successor to the original HamClock. Deployable locally on a Raspberry Pi or via the cloud, it centralizes essential DX operations into a single, intuitive interface. At its core is an interactive world map that visualizes real-time DX spots, signal paths, satellite tracking, and POTA activators. The software seamlessly integrates critical tools like WSJT-X, DX Cluster, and PSKReporter for monitoring digital traffic. Additionally, it provides vital environmental data, including real-time space weather indices, solar activity, and personalized HF propagation predictions. With customizable themes and a modular architecture, OpenHamClock offers modern operators comprehensive, at-a-glance situational awareness of global radio conditions

When assembling a robust shack, the quality of interconnects often determines overall system integrity and signal fidelity. Neutrik, with over 50 years in the connectivity sector, specializes in professional-grade connectors that withstand rigorous use in entertainment and industrial applications. Their product range includes XLR, speakON, powerCON, and opticalCON series, which are frequently adapted by hams for critical station infrastructure, particularly in contesting or DXpedition environments where reliability is paramount. Amateur radio operators often repurpose these durable connectors for antenna switching matrices, audio interfaces for digital modes, or power distribution systems. The robust locking mechanisms and high-quality contact materials found in Neutrik products ensure stable connections, minimizing intermittent faults that can plague field operations or even fixed station setups. This attention to mechanical and electrical integrity aligns well with the demands of high-power RF environments and sensitive receive chains. While primarily serving the pro-audio and video markets, the engineering principles behind Neutrik's designs translate directly to the needs of radio amateurs seeking superior performance and longevity from their cabling and connection points. Their commitment to innovation, as highlighted by their 50-year journey, suggests a continuous evolution of products that could benefit future amateur radio applications.

Constructing a high-performance RF spectrum analyzer up to 1000 MHz requires careful attention to component selection, shielding, and circuit isolation. This resource details a project that improves upon the _Spectrum Analyzer for the Radio Amateur_ design by Wes Hayward (W7ZOI) and Terry White (K7TAU), incorporating ideas from Scotty Sprowls' project, particularly his 1013.3 MHz IF bandpass cavity filter. The analyzer utilizes a Mini-Circuits SRA-11 mixer with a sweeping local oscillator from 1013 to 2013 MHz, feeding into a 4-pole copper pipe cavity filter. The design employs a second SRA-11 mixer with a fixed 1024 MHz LO to produce a 10.7 MHz final IF. This signal then passes through narrowband resolution filters and is processed by Analog Devices AD603 and AD8307 ICs for IF amplification and logarithmic detection, driving an oscilloscope in X/Y mode. The project emphasizes modular construction, using salvaged components and double-sided FR4 material for PCBs, with critical notes on minimizing spurious images through effective shielding and proper voltage regulation for each module. Key components include a Z-Communications V585ME48 VCO for the first LO and a Z-Comm V583ME01 VCO controlled by a Motorola MC145151 PLL for the second LO. An optional Hittite HMC307 step attenuator and K&L 5L121-1000/T5000-O/O low-pass filter manage RF input. Tuning procedures for the 10.7 MHz IF resolution filter are also detailed, showing before-and-after spectrum views.

Provides custom battery pack assembly services, focusing on portable power solutions for two-way radio applications. The company distributes batteries from numerous manufacturers, ensuring a broad selection for various radio models. This includes replacement packs for popular brands such as _Kenwood_, _Icom_, and Yaesu handheld transceivers, as well as batteries for CB radios and scanners. The core business function involves designing and building specific battery configurations to meet unique customer requirements, extending the operational life of portable radio equipment. Their offerings support a wide range of amateur radio activities requiring reliable, field-deployable power sources. Advanced Battery Systems also supplies individual cells and components, enabling radio operators to repair or rebuild existing battery packs, potentially saving costs compared to purchasing new OEM units. They emphasize durability and performance in their custom builds, aiming for **extended cycle life** and **consistent power output**.

Showcasing a diverse portfolio, RF Industries specializes in interconnect solutions crucial for modern communication infrastructure. Their product line encompasses a wide array of RF connectors, precision-engineered coaxial cables, and robust data cables, all designed to meet the rigorous demands of wireless and wireline telecom, data communications, and industrial applications. The company emphasizes its role in "Connecting the Next Generation" by providing foundational components for evolving network technologies. Their offerings extend beyond basic components to include comprehensive installation and test kits, alongside various adapters and wire harnesses. This focus ensures that their products not only perform reliably in the field but also integrate seamlessly into complex systems, supporting critical infrastructure. RF Industries' commitment to quality and innovation positions them as a key supplier for those building and maintaining advanced communication networks, from _5G deployments_ to industrial control systems, ensuring signal integrity and robust connectivity.

CATSync V1.30 integrates OpenWebRX support, expanding its capability to synchronize a local amateur radio transceiver's CAT control with a broader range of public WebSDR receivers. The software facilitates real-time frequency tracking, allowing the operator to adjust their physical rig's VFO and observe the connected WebSDR instantly follow the tuned frequency. This functionality is crucial for remote listening, signal comparison, and verifying propagation conditions across different geographic locations using a familiar hardware interface. The application supports both the classical WebSDR interface and KiwiSDR platforms, providing a consistent control experience across various online SDR deployments. It bridges the gap between local station operation and the vast network of globally distributed software-defined radios, offering a practical tool for DXers and contesters. CATSync is designed for Windows and Linux environments, with Android compatibility noted, making it accessible to a wide user base seeking to leverage WebSDR resources with their existing station setup.

RF amplifier products from NP Technologies, Inc. encompass a wide array of specialized designs, including highly linear Class A broadband amplifiers, crucial for maintaining signal integrity across various frequencies. Their portfolio also features cell band amplifiers, specifically engineered for cellular communication infrastructure, and pulse amplifiers, which are vital in applications requiring high-power, short-duration signal bursts. The company's manufacturing capabilities extend to AM and FM broadcast amplifiers, supporting radio transmission systems, and military VHF amplifiers, designed to meet rigorous defense specifications for robust and reliable communications. NP Technologies, Inc. emphasizes comprehensive development, design, manufacturing, and testing processes for all its RF amplifier offerings. This integrated approach ensures that each product, from initial concept to final deployment, adheres to stringent performance and reliability standards. The company's expertise in these areas allows for the creation of custom solutions tailored to specific client requirements, addressing complex RF challenges in diverse operational environments. Their product range demonstrates a commitment to serving multiple sectors, including commercial broadcasting, telecommunications, and defense. The focus on specialized amplifier types underscores their technical depth in RF engineering.

Comprod Communications specializes in the design and manufacturing of RF communication solutions, including a comprehensive range of antennas, duplexers, multicouplers, and combiners. The resource details their product categories, which encompass base station antennas, mobile antennas, transit antennas, and disguised antennas, alongside mounting solutions and in-building systems. It highlights the company's 40-year history in adapting offerings to client needs and anticipating industry trends, emphasizing product durability and low maintenance for harsh environments. The company's offerings are presented as high-quality, designed to withstand extreme conditions from Arctic cold to equatorial heat and humidity. The site mentions solutions and technical sales support, training, and site analysis and system design as part of their service portfolio. It also references being a market leader trusted by over 1,000 customers worldwide, positioning itself as a partner for RF communication needs.

Cmpter Electronics specializes in the design and manufacturing of RF coaxial connectors, RF adapters, and RF cable assemblies, serving diverse applications across datacom/telecom, automotive, instrumentation, aerospace, and defense sectors. Their product line includes RF coaxial terminations, attenuators, and waveguide to coax adapters, catering to specific needs in radio frequency systems. The company also offers precision adapters and connectors, alongside glass beads and test cable assemblies, indicating a focus on high-quality components for demanding RF environments. Their resource center provides valuable information, including an "RF Made Simple" section and a product catalog for download, which assists engineers and technicians in selecting appropriate components. The product named system helps in identifying specific parts, streamlining the procurement process for complex RF solutions. With a comprehensive range of RF coaxial cables and related tools, Cmpter Electronics positions itself as a key supplier for critical infrastructure requiring reliable signal integrity. Their offerings support a broad spectrum of RF applications, from basic connectivity to advanced test setups.

GoGreenSolar provides comprehensive solutions for **DIY solar panel systems**, catering to both homeowners and professionals seeking energy independence or reduced utility costs. Their offerings include a variety of solar kits such as Grid-Tie, Off-Grid, and Battery Backup configurations, designed to integrate seamlessly with existing utility infrastructure or provide complete autonomy in remote locations. Customers can select from Microinverter or String Inverter kits, along with essential components like **solar panels**, inverters, batteries, and racking systems, all curated from reputable brands known for efficiency and durability. The company emphasizes end-to-end support, from initial consultation and custom system design to providing easy-to-follow installation manuals. They offer financing options, including quick-approval loans with zero down payment, and a money-back guarantee if a solar permit is not approved. The platform also features a solar calculator and a questionnaire to help users determine the most suitable system for their specific energy requirements and property characteristics. GoGreenSolar aims to simplify the solar adoption process, enabling significant savings on energy bills and labor costs. Their approach focuses on empowering users to install their own systems with expert guidance, ensuring optimal performance and a secure energy future for homes and businesses.

Martek Power designs and manufactures a wide of high performance power supplies for various industries. Power supplies AC-DC, DC-AC inverters, DC-DC, EMI Filters

The _Nemos Photography_ blog presents a curated visual gallery focusing on _Morse keys_, offering a detailed photographic exploration of various telegraphy instruments. Each entry typically features high-resolution images of specific keys, highlighting their design, construction, and historical context. The content serves as a visual reference for collectors and enthusiasts interested in the aesthetics and mechanics of CW sending devices, often including close-ups of key components and unique features. This resource allows for comparative study of different key types, from vintage straight keys to modern paddles, without delving into technical specifications or operational performance. The emphasis is purely on the visual documentation of these artifacts, providing a unique perspective on the evolution and diversity of Morse key designs. It is a specialized collection for those who appreciate the craftsmanship and historical significance of telegraphy hardware.

Demonstrates the construction of a high-power 6-meter (50 MHz) amplifier, specifically designed for demanding modes like EME, TEP, and multiskip Es. It details the use of a _GU-43B_ tetrode in a grounded-cathode configuration, emphasizing the need for stabilized grid voltage and input capacitance compensation. The resource provides a comprehensive schematic, power supply design, and practical considerations for component sourcing, particularly for high-voltage and high-current sections. The builder achieved an output power of **1250 watts** with an anode current of 0.65 amperes and 3200 volts anode voltage. The article also covers the physical construction within a modified P6-31 enclosure, outlining the internal layout for RF and power supply sections, and includes photos of the completed unit. It highlights critical safety precautions for working with high voltages and reactive currents up to **20 Amperes** in the P-network.

An online multiple calculator of 16 impedance matching networks

Details Amphenol's extensive product line, encompassing electrical, electronic, and fiber optic connectors, alongside coaxial and flat-ribbon cable solutions. The company designs, manufactures, and markets these interconnect systems globally, serving various communication network requirements. Their offerings support end-to-end connectivity, crucial for modern broadband infrastructure. Emphasizes the company's role as a major provider of components vital for reliable signal transmission in diverse applications. Products like _LMR(R) coaxial cables_ and various _RF connectors_ are essential for amateur radio installations, ensuring low loss and robust connections for antennas and transceivers. The focus on high-performance interconnects directly benefits hams constructing or upgrading their stations. Amphenol's broad portfolio includes specialized connectors and cable assemblies, meeting rigorous technical specifications for both commercial and amateur radio use.

Operating in the **microwave** spectrum, Response Microwave, Inc. specializes in the design and manufacturing of RF and microwave signal processing components and subsystems. The company's product line encompasses a wide array of offerings, including Connectivity Series components, rotary joints, phase shifters, cable assemblies, surge protectors, terminations, Hybridline/Couperline products, circulators/isolators, directional couplers, quadrature hybrids, attenuators, custom assemblies, filters/diplexers, DC blocks & bias tees, power dividers/combiners, laser diodes & drivers, high-frequency connectors, and precision test accessories. This extensive catalog supports various applications requiring precise signal manipulation and transmission at elevated frequencies. The resource provides access to a comprehensive product catalog and a dedicated connector catalog, detailing specifications for components like **high-frequency connectors** and test cables. While specific performance data or comparative analyses are not directly presented on the main page, the breadth of products indicates a focus on providing foundational building blocks for microwave systems. The company emphasizes customer service and aims to be a reliable source for RF/Microwave/Optics product requirements, serving a growing customer base with its specialized component offerings.

Microprocessor based interface designed receives a signal from a Morse key, processes it, and re-transmits it to the radio. A microprocessor in the circuit is pre-programmed with a proprietary algorithm which makes a number of measurements and adjustments to the less percise human generated code.

The prototype for this amplifier was originally designed for 70cm and was used on the 2004 3B9C Dx-pedition to Rodriguez Island for satellite and EME. It had a noise figure of 0.49dB with an associated gain of 20dB.

Design, develop, test and manufacture a wide range of Amplifier products including highly linear class A Broad Band, Cell Band, Pulse, AM & FM broadcast and Military VHF

Accurate meteorological data is crucial for optimizing antenna performance, predicting propagation, and ensuring safe tower work. This resource provides a curated inventory of weather stations, including models like the _AcuRite Atlas_ with lightning detection and the _Ambient Weather WS-2902_ WiFi Smart Weather Station, which offer real-time data on environmental factors. The product listings detail specific features such as direct-to-Wi-Fi connectivity, rainfall tracking, and temperature insights, enabling informed decision-making for various amateur radio operations. The platform categorizes products by application, featuring weather stations tailored for home and backyard use, as well as more robust systems for farm and agriculture, which can be critical for field day operations or remote station monitoring. It also highlights _Made in USA_ options, emphasizing local manufacturing and support. Beyond weather instruments, the site also presents related surveillance technology, such as the _Waggle solar CCTV camera_, designed for outdoor reliability with an IP65 weatherproof rating. This integration allows for comprehensive monitoring of remote ham radio shacks or antenna sites, combining environmental data with visual oversight.

Showcasing innovative RF solutions, Hofi Hochfrequenztechnik manufactures high-quality _antennas_ and RF switches. Their products, including the **versatower** and **fritzel** brands, cater to both casual operators and serious DXers. With a commitment to performance, Hofi's offerings enable operators to achieve optimal signal gain and reliability in various conditions. The company's expertise in antenna design ensures that users can effectively communicate across _HF_ bands, enhancing their overall operating experience. Whether setting up a new station or upgrading existing equipment, Hofi provides essential tools for successful ham radio operations.

Monitoring extremely weak signals in the QRSS (Very Slow Morse) mode requires specialized receiving and processing capabilities to extract information below the typical noise floor. This project provides a software solution, _QrssPiG_, designed to run on a Raspberry Pi, enabling it to function as a dedicated QRSS grabber. It interfaces with various Software Defined Radio (SDR) devices, including the popular _rtl-sdr_ dongles and _HackRF_ units, to acquire raw I/Q data streams. The software then performs the necessary signal processing to visualize and decode these faint, long-duration CW transmissions, often operating with milliwatts of power. The system leverages the computational power of the Raspberry Pi for real-time signal analysis, allowing hams to participate in QRSS experiments and monitor distant beacons. It supports different SDR hardware, offering flexibility in setup and deployment for home stations or remote monitoring sites. The project includes detailed instructions for installation and configuration, making it accessible for those familiar with Linux environments. This grabber is particularly useful for tracking propagation on the LF and HF bands where QRSS activity is common, providing a visual representation of signal presence over extended periods.

The calculator designs the Yagi-Uda antenna based on the DL6WU model with boom correction, following the G3SEK-DL6WU method. It optimizes the antenna for maximum gain and allows adjustment of passive elements without affecting SWR. DL6WU antennas are known for their high gain, minimal sensitivity to nearby objects, and stable performance in various weather conditions.

The Kenwood TM-D710 is designed as a nearly fully self-contained APRS station, with the ability to perform most of the common APRS functions built right in.

XieGu Tech manufactures quality amateur radio transceivers and amplifiers designed by BG8HT. Xiegu focus is portable and self contained transceivers perfect for your next SOTA, hiking trip or travel experience.

SDR++ is a cross-platform, open-source SDR software designed for minimal bloat and ease of use, supporting Windows, Linux, macOS, and BSD operating systems. It incorporates multi-VFO capabilities and offers extensive hardware compatibility through both _SoapySDR_ and dedicated modules. The software features SIMD accelerated DSP for efficient signal processing and provides full waterfall updates when possible, which enhances signal browsing. Its modular design facilitates the development of custom plugins, allowing users to extend its functionality. The application's focus on a bloat-free architecture and user-friendly interface aims to simplify the experience of working with Software Defined Radios. The full waterfall update mechanism is particularly beneficial for visualizing and identifying signals across a wide frequency spectrum, improving operational efficiency for radio amateurs. The modular plugin system enables community contributions and specialized enhancements, making _SDR++_ adaptable for various amateur radio applications, from general listening to specific digital mode decoding.

Designing and constructing a two-element receiving loop antenna array for HF operation involves specific considerations for achieving high directivity and noise reduction. This resource details a homebrew system comprising two 30-inch diamond-shaped loops, spaced 20 feet apart, which are fed through mast-mounted preamplifiers and passive signal combiners. The operational principle relies on adjusting phase delays between elements via precise _Belden 8241_ coaxial cable lengths, optimized for specific bands from 160m to 20m. Performance data, derived from _EZ-NEC_ modeling, illustrates consistent 90° azimuth-plane beamwidth and low take-off angles across the target bands, with _Receiving Directivity Factor_ (RDF) values comparable to a 300-foot Beverage antenna. The article presents detailed elevation and azimuth plots for 20m, 30m, 40m, 80m, and 160m, demonstrating the array's ability to provide strong response at low DX angles while also supporting _NVIS_ signals. Key components like the _DX Engineering RPA-1_ preamplifier and _DXE RSC-2_ signal combiner are discussed, alongside the importance of impedance matching to preserve antenna patterns. The construction emphasizes self-contained elements that do not require ground radials, offering a compact solution suitable for suburban environments and stealth installations, with a focus on optimizing receive performance independently from transmit antennas.

A microprocessor based interface designed to go between a standard Morse code key and a radio transmitter. The circuit receives a signal from the key, processes it, and re-transmits it to the radio.

Operating a modern amateur radio station, particularly for advanced digital modes or microwave experiments, often requires precise test and measurement equipment. This resource from NI (National Instruments), now part of Emerson, showcases a wide array of hardware and software solutions designed for demanding test objectives. Their portfolio includes modular instruments and configurable software interfaces, such as _LabVIEW_ and _TestStand_, which integrate AI assistance via _NI Nigel™ AI_ for code completion and sequence building. For those involved in RF and microwave work, the offerings extend to vector signal transceivers, RF signal generators, software-defined radios, and spectrum analyzers. These tools are crucial for characterizing antenna performance, optimizing transceiver circuits, or developing custom radio systems. The company emphasizes its 50 years of innovation, with 40 years dedicated to _LabVIEW_, highlighting a long-standing commitment to engineering solutions. The site also details products for data acquisition, electronic test, and wireless design, covering components like CompactDAQ modules for precise sensor measurements and various communication bus interfaces. Their events and perspectives sections offer insights into topics such as 5G technology and strategies for breaking out of testing silos, providing a broader context for their measurement solutions.

Designer and manufacturer of RF amplifiers used in a variety of custom applications in many diverse industries - from Scientific, Medical, Industrial, and Communications and Broadcast.

Over 100 distinct RF connector types are available from AIR802, including popular UHF series PL-259 plugs and SO-239 sockets, designed for a wide array of coaxial cable dimensions. The company specializes in producing connectors compatible with common amateur radio cables like RG-8, RG-213, and RG-58, ensuring reliable signal integrity for antenna systems and shack interconnections. Their product line extends to various coaxial cable types and pre-made antenna cable assemblies, offering ready-to-deploy solutions for hams. AIR802 also provides custom cable assemblies and pigtails, catering to specific installation requirements for transceivers, tuners, and amplifiers. These pre-fabricated options simplify station setup, reducing the need for field termination of connectors. Michael Bryant is the contact for inquiries regarding their range of RF components, which are essential for building robust and efficient amateur radio stations.

_AT Auto_ is an automatic antenna tuner designed for amateur radio enthusiasts seeking efficient and reliable tuning solutions. This device automates the tuning process, allowing operators to focus on communication rather than manual adjustments. The tuner is compatible with a range of transceivers, enhancing its versatility in different shack setups. Its design incorporates advanced circuitry to ensure optimal performance across various bands. The _AT Auto_ tuner is particularly useful for those operating in HF bands, providing seamless transitions between frequencies. Its integration capabilities with other shack automation products make it a valuable component for modern amateur radio stations. The tuner supports multiple modes, including _SSB_ and _CW_, catering to diverse operating preferences. Its robust construction and user-friendly interface contribute to its appeal among both seasoned operators and those new to the hobby. Kessler Engineering's focus on innovation and quality is evident in the _AT Auto_'s design. The tuner is part of a broader product line that includes shack automation solutions, reflecting the company's commitment to enhancing amateur radio operations. Despite the website redesign, the tuner remains a key offering in their product portfolio.

The OCFD Off-Center-Fed Dipole Antenna is an excellent multiband antenna that is relatively simple to construct, yet gets quite decent performance.

Constructing an End-Fed Half-Wave (EFHW) antenna offers a practical solution for HF operators seeking a multiband wire antenna without the need for extensive radial systems. This design typically employs a high-impedance transformer at the feed point, matching the antenna's inherent high impedance to a 50-ohm coaxial feedline. The article specifically details a 2012 approach, focusing on a transformer with a 49:1 turns ratio, which is a common configuration for EFHW antennas. The resource outlines the construction of a wire element cut for a half-wavelength on the lowest desired band, with specific coil arrangements enabling operation on harmonically related bands such as 40m, 20m, and 10m. It discusses the physical dimensions and winding details for the matching transformer, often utilizing a ferrite toroid core to achieve the necessary impedance transformation. The content provides insights into the operational principles and practical considerations for deploying such an antenna, including methods for tuning and optimizing performance across multiple amateur radio bands. While acknowledging that the presented information from 2012 may be superseded by newer insights, it serves as a foundational reference for understanding EFHW antenna theory and construction.

A 0-30 MHz step attenuator, constructed from switchable Pi attenuation pads, provides a practical tool for evaluating receiver sensitivity and calibrating S-meters. The design utilizes readily available 5% tolerance resistors, with values derived from paralleled components to achieve specific attenuation steps. A schematic (Fig 1) illustrates the circuit, including PCB pad shielding, while a table details required and actual resistor values, along with percentage differences. Measurements of voltage input versus output at various frequencies are used to calculate dB attenuation, presented in a graph (Fig 4). The resource includes formulas for determining output voltage from a known input and a comprehensive 0-40 dB voltage multiplier table, which is crucial for precise signal level management. The project also references external attenuator calculators and equations for further study. Photos (1-3) provide visual guidance for the assembled unit, showing bottom, top, and front views. The project emphasizes the use of **Pi attenuation pads** and **receiver sensitivity** evaluation, offering a hands-on approach to RF signal management.

The San Bernardino Microwave Society, operating under the callsign _W6IFE_, serves as a significant technical hub for amateur radio operators specializing in frequencies above 1 GHz. This organization's influence extends across Southern California, providing a centralized resource for advanced RF experimentation and **regional frequency management** within the microwave spectrum. Its permanent value lies in its extensive archive of technical papers and project documentation, which are critical for operators engaged in high-frequency design and deployment. The society's infrastructure is primarily intellectual, focusing on the dissemination of specialized knowledge rather than a conventional repeater network. It offers a robust collection of technical papers from prominent members like K6PIP, K6BLG, and WA6EXV, covering topics such as Rubidium oscillator data, logging software, and filter design. This resource facilitates advanced amateur radio operations, including participation in microwave contests and the development of custom transverters for bands like 24 GHz. The site also details various member projects, such as the Owens Valley Radio Observatory Project, showcasing practical applications of **RF propagation analysis** and system integration. DXZone Focus: Microwave | Technical Papers | RF Propagation | Contest Results

Demonstrates MegaPhase's extensive product line of RF and microwave coaxial cable assemblies and components, engineered for demanding applications up to 110 GHz. Key offerings include _Test & Measurement Cables_ with superior phase and amplitude stability, _RF & Microwave Cables_ utilizing _GrooveTube®_ technology for high power systems, and a range of RF components like directional couplers and power dividers. The site details specific cable types such as _Alumibend™_ for space-qualified, ultra-light applications through 90 GHz, and armored cables designed for rigorous environments up to 50 GHz, emphasizing their robust mechanical strength and measurement repeatability. The resource highlights applications across diverse sectors, including space programs like the _Hayabusa_ mission, global security (C5ISR), military airborne systems (MIL-T-81490), telecom, and automated testing. It also provides technical insights through "How To" guides on measuring amplitude/phase stability vs. flexure and proper connector cleaning. The company's commitment to quality is underscored by its rigorous testing protocols and a strong warranty, ensuring reliable operation in critical systems.

Station QRP presents various **circuit diagrams** for constructing low-power AM vacuum tube shortwave transmitters, catering to enthusiasts interested in vintage radio technology. The resource details schematics ranging from simple to more complex designs, enabling hams to build their own QRP AM transmitters for operation on frequencies like 6.925 kHz AM. It emphasizes the use of vacuum tubes, providing a technical foundation for understanding and replicating classic shortwave broadcasting methods. The content is geared towards those who enjoy the hands-on aspect of electronics and the unique characteristics of tube-based RF circuits. Building these transmitters allows operators to experience the nostalgia of early shortwave radio, with the site specifically mentioning a pioneer station on 6.925 kHz AM. The designs facilitate experimentation with low-power AM transmission, offering practical application for homebrew projects. The focus on QRP (low power) operation aligns with a segment of the amateur radio community that values efficiency and minimalist setups, providing a distinct alternative to modern solid-state transceivers.

Designs, engineers and markets a unique line of mobile and fixed station RF communications antennas with a key focus on maximizing antenna value.

an overview, introduction or tutorial about the basics of electronics filters including the types of filter and the various filter design considerations and parameters

Delivering confidence to confront the most challenging microwave and RF designs. Spectrum Analyzers by Tektronix

DataBridge wireless RF modem modules facilitate point-to-point data transmission, supporting analog, digital, and serial RS232 UART signals. These modules are engineered for robust wireless communication, offering a reliable solution for various industrial and amateur radio applications requiring secure data links. The product line includes specific models designed for different frequency ranges and power outputs, ensuring compatibility with diverse operational requirements. Each module integrates advanced RF technology to maintain signal integrity over distance, crucial for remote monitoring and control systems. The design emphasizes ease of integration, allowing users to quickly deploy wireless data links without extensive configuration. Key features encompass low power consumption and a compact form factor, making them suitable for embedded systems and portable devices.

The AA4F Key Contact Cleaner is designed for maintaining key contacts, ensuring reliable operation in 2-way radio communications. **Regular use** of this cleaner can significantly improve contact performance, reducing the risk of intermittent signals. It is particularly effective for cleaning contacts on various key types, including _straight keys_ and _paddles_. Proper maintenance extends the lifespan of your equipment, ensuring consistent operation during contests and DXing activities. Users report improved key responsiveness and reduced key chatter, which is crucial during high-pressure operating conditions. Regular cleaning can prevent oxidation and buildup, which can lead to erratic key performance. This product is essential for serious operators who rely on their equipment for successful communication.

A multi tool Windows program that has been designed to offer the EMC RF and Radio Engineer a large variety of tools for Attenuation calculation, VSWR analysis, FIR Filter calculations, EMC system configuration, Radar testing , RF Filter calculation and much more without the need of a live internet connection.

The Tri-pole antenna, a clever modification of a standard dipole, allows for dual-band operation by integrating a third element. This design effectively shortens the overall dipole length by 10 to 20 percent, simplifying antenna rotation and offering a compact footprint. KK4OBI's article delves into the operational principles, using a 6 and 10-meter Tri-pole as a primary example, and provides comprehensive instructions for constructing any Tri-pole antenna within the 6 to 15-meter range. Key to the Tri-pole's performance is its off-center feed, necessitating a common mode choke at the feed point for optimal tuning and reduced noise. The author outlines a methodical approach to determining element dimensions, starting with a vertical element frequency calculated as 0.47 times the sum of the desired upper and lower band frequencies. This calculation, along with K-values derived from trend lines, guides the initial lengths for the horizontal arms, demonstrating how a 10m-6m Tri-pole can achieve a total horizontal length 78% shorter than a conventional 10-meter dipole. Tuning and balancing are critical, with the article detailing adjustments to arm lengths and the vertical element to achieve balanced SWR values, as validated through 4NEC2 simulations. Radiation patterns are analyzed at various elevations, showing gains around 5.7 dBi and favorable take-off angles for DX contacts. Construction details specify aluminum tubing dimensions, U-bolts, and an SO-239 connector, emphasizing the importance of a ferrite-based choke for wideband operation.

Valon Technology designs and manufacturers low cost, reliable radio frequency products such as RF Synthesizer modules, RF Frequency Dividers and Phase Gain Detectors. Main markets are military/defense, test engineering, radio astronomy, research centers and universities

The online Morse code translator and decoder provides functionality for converting plain text into Morse code and decoding Morse code back into text. Users can input text directly into a designated box for translation to Morse, with the tool ignoring characters that lack a Morse equivalent. Conversely, Morse code can be entered using periods for dots and minus signs for dashes, requiring a single space to separate letters and a forward slash to delineate words. The interface also supports direct Morse input via a button, where a half-second pause separates letters and a 1.5-second pause separates words. The resource details the historical context of Morse code, noting its invention by _Samuel F.B. Morse_ in the 1830s for telegraphy, and its continued use by amateur radio operators for recreational purposes and emergency signaling, such as the **SOS distress signal**. Guidance on learning Morse code suggests using online translators for practice and listening to amateur radio transmissions. The tool offers an audio playback feature for translated Morse, allowing users to hear the code at various words per minute (WPM) settings. It also includes a visual chart to aid in memorizing the dot and dash sequences for the alphabet.

Northern Connectors offers over 30 years of experience distributing specialized electro-mechanical connectors and related components, primarily serving industrial environments. The company partners with manufacturers such as _Binder_, _Hummel_, and _Mencom_, providing access to a broad range of connectivity solutions including circular connectors, heavy-duty connectors, and sensor cables. Their product lines are designed to address demanding technical requirements in various sectors, ensuring robust and reliable connections for critical systems. The resource details specific product categories like M5, M8, M12, M16, M23, and M40 connectors, alongside power and data transmission solutions. It emphasizes the availability of custom cable assemblies and overmolded solutions, tailored to unique client specifications. The site also highlights their technical support capabilities, assisting customers in selecting appropriate components for complex applications. Northern Connectors maintains a significant stockholding in the UK, facilitating prompt delivery of essential components. They focus on providing solutions that meet stringent industry standards for performance and durability.

Offers a range of high-performance RF interconnect solutions, addressing the critical need for reliable signal integrity across diverse radio frequency applications. Their product line includes custom cable assemblies, various **RF connectors** (such as SMA), adapters, and terminators, designed to meet stringent specifications from DC up to 40 GHz. These components are essential for maintaining low insertion loss and excellent VSWR in demanding environments, from test benches to operational communication systems. The company specializes in providing tailored solutions for both commercial and government sectors, emphasizing precision manufacturing in Warner Robins, Georgia. Their offerings are crucial for engineers and operators requiring specific lengths, connector types, and performance characteristics for their radio equipment and test setups. Ensuring robust connections and protection against transient voltage events, their **surge protectors** are integrated into systems to safeguard sensitive electronics from damage, a common concern in outdoor or high-power installations.

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