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Makers of QRP HF General Coverage Transceivers you can build. The Home of BITX transceivers, uBITX General Coverage Receiver-Transmitter. A general coverage, 10 watts HF SSB/CW transceiver kit with features you NEED for operating ease, convenience and versatility. It works from 3 MHz to 30 MHz, with up to 10 watts on SSB and CW, with a very sensitive receiver.

How to build and connect the M710 Remote Cable

Building a LEO satellite ground station, and eggbeater antenna for the 70cm band

Building an omnidirectionnal antenna for the 23 cm band

1500 watts PEP SSB is the power handling capability of the MFJ-989C HF Antenna Tuner, a popular choice among amateur radio operators. Users have shared a wide range of experiences, with some praising its durability and performance over decades of use, while others criticize its build quality and accuracy. The tuner features a built-in dummy load, SWR-wattmeter, and a balun for balanced line feeders, making it versatile for various antenna setups. However, discrepancies in RF power readings and SWR measurements have been noted, with some users finding the dual scale meter to be off by about 20% compared to a Bird wattmeter. Long-term users report that the MFJ-989C performs well with proper antenna setups, but caution against tuning at high power without initial adjustments at lower power levels. Some have experienced issues such as arcing when exceeding 400 watts, while others have had no problems even at higher power levels. The roller inductor and capacitors are functional, though some users have had to perform maintenance like tightening screws or cleaning components to ensure reliable operation. Despite mixed reviews, the MFJ-989C remains in production, suggesting continued demand. It's a tuner that requires careful handling and possibly some DIY fixes to achieve optimal performance.

APRS4R Digipeater configuration notes by K6DBG

13cms and 23cms ATV my projects and builds. Also using wifi amps on 13cms, 13cms dish feeds using a Sky dish. GB3CZ

Examines Radio Frequency Systems (RFS), a manufacturer specializing in high-performance cable solutions for diverse communication infrastructures. The company, with over 120 years of heritage, focuses on designing and producing robust, long-life connectivity systems, including _low loss foam dielectric RF cable_ and _premium radiating cable_. RFS's product range supports critical applications in cellular networks, microwave antenna systems, and specialized installations within buildings and tunnels. The resource highlights RFS's commitment to innovation, addressing emerging industry standards like _FRMCS_ for railway communication and advanced fiber solutions for data centers. It also details the company's manufacturing capabilities in Hannover, Germany, emphasizing the quality and reliability associated with _Made in Germany_ products. The content covers various connectivity landscapes, from urban solutions for connected cities to private 5G credentials and future plans. Specific product categories include _fiber, power & hybrid cable_, and _low loss high power air dielectric RF cable_, showcasing their broad portfolio for complex RF environments.

If you like building good antennas, this one is for you. The J-pole is a slim, omnidirectional, half-wave antenna fed at the end through a quarter-wave shorted transmission line. Its predecessor is the famous Zepp antenna developed for the Zeppelin airship.

Selecting appropriate coaxial cable and wire for demanding amateur radio applications, particularly those involving high power or harsh environmental conditions, is crucial for maintaining signal integrity and operational safety. This resource details Harbour Industries' specialized offerings, which include Mil-Spec and commercial designs such as NEMA HP3/HP4 and SAE AS22759, suitable for aerospace, military, and industrial sectors. Their product line addresses the need for robust conductors capable of withstanding extreme temperatures and mechanical stress, often encountered in antenna systems or amplifier interconnections. The company highlights its AeroPOWER® Firezone M25038/3 cable, specifically engineered for high-temperature environments like aircraft engines. This particular product exemplifies their focus on solutions for critical infrastructure where reliability under adverse conditions is paramount. Such cables are relevant for hams building or maintaining stations in challenging climates or those operating high-power amplifiers where internal wiring must endure significant thermal loads. Harbour Industries also provides a range of high-performance cables designed to meet stringent specifications. Their expertise in high-temperature and high-performance cable manufacturing positions them as a supplier for specialized wiring needs beyond standard off-the-shelf options, ensuring durability and performance for advanced amateur radio setups.

Full article on how to build a home-made wire dipole antenna for 40 and 80 meters band. Article is fully in italian, as it was published on ARI RadioRivista, but is plenty of self explaining pictures that will guide you on homebrewing this trapped dipole antenna for the lower amateur radio bands.

Ham Cockpit is a program of a new type. All of its functions are implemented in the plugins, the main program simply loads the plugins and helps them work together. Ham Cockpit is an integrated environment for a Radio Amateur that every user can build according to his needs. It can work as SDR client, a logger, a cluster monitor, a propagation prediction tool, or have any combination of these working together.

9M6MU Alfons details his family's efforts to establish an independent, self-sufficient home at Eagle Plateau in Borneo, a 50-acre highland property. The resource highlights their integration of **solar photovoltaic panels** for power generation, alongside managing water supplies, organic gardens, and fruit trees. It covers the practical challenges and rewards of living off-grid, including maintaining power generators and addressing infrastructure needs, all while pursuing the hobby of amateur radio. The narrative emphasizes a holistic approach to healthy living and nature conservation, reflecting the family's aspirations for an ideal ham world. Alfons and his XYL Doris share their experiences in building shelter and antenna farms, showcasing their dedication to independence and sustainable practices away from the conventional grid. The site also references the Hillview Gardens Amateur Radio Club, suggesting community involvement.

AMSAT is a worldwide group of Amateur Radio Operators who share a common interest in building, launching and communicating with each other through non-commercial Amateur Radio satellites.

Build a 7 Element 4M (70MHz) Beam By Paul M1CCZ

Pictures of the restructuring of the ham shack starting from an existing garage. Changes includes isolation of walls and roof and rebuilding of the radio table.

The N1HFX thermal cooling fan controller project details a practical circuit designed to manage cooling fan operation based on temperature, a common requirement for high-power amateur radio equipment. This build utilizes a **LM34** temperature sensor, providing a linear voltage output directly proportional to Fahrenheit degrees, simplifying the control logic. The circuit's core functionality involves a comparator that activates the fan when a preset temperature threshold is exceeded, ensuring efficient cooling and reducing unnecessary fan noise. This controller is particularly useful for amplifiers, power supplies, or transceivers that generate significant heat during operation. The design incorporates a _TIP120 Darlington transistor_ to drive the fan, capable of handling up to 5 amps, making it suitable for a range of fan sizes and current requirements. Field results indicate stable temperature regulation, preventing thermal runaway in enclosed environments. Construction involves readily available components, making it an accessible project for hams looking to optimize their station's thermal management.

Experimenting a 20 40 meter short coil loaded dipole antenna with the goal to keep the total length under 40 feet so that the dipole can be mounted on two 20 foot fiberglass pole to make a 20/40 meter rotatable dipole.

Details the Big Thunder Amateur Radio Club (BTARC), a long-standing amateur radio organization based in Boone County, Illinois, established in 1962. It covers the club's mission to enhance the skills of local hams, promote radio knowledge, and foster social interaction among operators. The resource outlines BTARC's commitment to community service, including emergency communications support through RACES, and its active participation in events like Field Day, fox hunts, and public service communications for local races. Explains the club's history, including the establishment of its first repeater in the 1970s by members WD9JGH, Mike George, K9ORU, and Claude Horsman, WB9PMM, using a VHF Engineering kit and a Sinclair duplexer. It provides specifications for two club-maintained FM repeaters: a 2-meter repeater on 147.375 MHz (+600 KHz shift, 100.0 Hz PL tone) and a 70-cm repeater on 442.825 MHz (+5 MHz shift, 114.8 Hz PL tone). The club hosts a weekly 2-meter net on Sundays at 7:00 PM local time and holds monthly meetings on the second Thursday at the Spring Township Building in Belvidere, IL.

Utility-Driven Tradeoff Analysis, if you want to geto on the microwave bands , you will have to choose the proper antenna for your operating conditions. How to decide is not always easy, and you may also decide to build your own antenna.

Building the W3NQN bandpass filters

A light and sturdy Quad for 10 and 15 meters. Basic Quad antenna design considerations. Building and assembling a dual band HF QUAD antenna, designing and joining cross-arms and boom, assembling spreader and element wire installation notes. QST article.

A very well done presentation about End-Fed Half-Wave antennas. This PDF document contains a summary of experiences in how to build custom EFHW antennas. Includes an interesting comparison table of UnUn configurations with recommended toroids, Wire size, turns and capacitors. An useful recap on common errors in building homebrew EFHW Ununs completes the document.

Building an amateur station for competitive radiosport involves a number of critical steps, regardless of the band or bands you focus on. These include, but are certainly not limited to: Station layout, Equipment interconnection and switching, Inter-station interference, Antenna selection. Radio interface with the logging program, CW and voice keyer integration, Rotator control

Building equipment for AMSAT P4A geostationary Es'hail-2 Quatar OSCAR 100 Satellite

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.

The standard J-Pole antenna is a end fed 1/2 wavelength antenna, in this article is explained also how to build an expanded Super J Pole that provides about 4.5 dbd gain. These antennas can be built from EMT electric conduit pipe

DIY speakers, resources for custom speaker hombrewing

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.

An experimental prototype of an asymmetrical hatted vertical dipole antenna that can work on HF bands 20 to 10 meters band. The AHVD Vertical dipole is an upside-down T design

Constructing a multi-band fan dipole for HF operation presents unique challenges, as VE2XIP demonstrates through his 2012 project to replace an existing commercial antenna. He details the process of calculating wire lengths using the 468/frequency formula, emphasizing the critical importance of equal leg lengths for each dipole element. The author shares practical insights gained from building at ground level, noting how elevation impacts resonant frequency and SWR, particularly for lower and higher bands. VE2XIP's experience highlights the iterative nature of antenna tuning, starting with the lowest frequency band (80m) and working upwards. He provides a specific example of trimming calculations and offers a clever tip for accurate wire removal. The article also touches on the mechanical aspects, such as dowel spacing for wire support and the benefits of a pulley system for repeated raising and lowering during the tuning process. Field results showed significant performance gains over the previous Alpha-Delta DX LB Plus, with **20 dB over 9** signal reports on 80m compared to 57. The project cost around **$100** for hardware, proving a cost-effective alternative. The author also discovered a bonus 6m capability and achieved an inverted-V _obtuse angle_ of approximately 115 degrees, contributing to a surprisingly stealthy installation.

How to build a low-pass filter to remove alternator whine from your car

Amateur radio kits dealer, online shop for ham radio transceiver kits.

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.

This circuit stores a morse code message as bits in an EPROM chip, the message controls a relay that keys a CW morse code transmitter. An Arduino processor can also be used in place of this circuit, that eliminates the need to build the circuit and program an EPROM.

A description and build-log of a cheap telescoping mast made from PVC pipe, string, and some misc mounting hardware. It is useful if you are going somewhere that doesn't have any trees nearby to hang something on.

Build a SPDT coaxial relay that can be used as a main Transmit/Receive relay or an A-B switch to select between two different 6m antennas

RSGB article for beginners. How to build a dipole antenna, construction tips and correct setup of inverted-ve dipole antennas

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.

A practical guide on hombrewing Yagi antennas, including notes on Driven Element, Transformation & Symmetrising Coax Lines, Full Boom length vs. electrical length, Elements & Insulators on Boom and additional tips and tricks, in English and German

Ham radio information for new CW and QRP operators. Includes operating advice, reviews and articles on kit building/rig repair,

Building the Three-Element Hex Beam. A project and construction phase of an HF hex-Beam antenna using trees to hang the antenna and a Channel Master antenna rotator.

Thoughts build a solid state legal-limit amplifier for amateur radio use.

Build a digital AC voltmeter to measure the output range from 0 to 150VAC with reasonable accuracy

When a broadcast antenna is to be placed on top of a building, there are special problems of feeding and grounding. The radiator is usually electrically short, that is, much less than one-quarter wavelength high.

Useful tips on building cobweb antennas. Since I've done so many posts on the Cobweb antennas I thought it best to separate them on a different page so that potential Cobweb builders can see all the posts together. Hopefully this will make planning and building easier.

The Cambridge University Wireless Society (CUWS) serves as the amateur radio society for students and staff at Cambridge and Anglia Ruskin Universities, fostering interest and activity in two-way radio communication. It provides a platform for members to engage with various aspects of amateur radio, including operating, technical experimentation, and community building within the university environment. The society's activities typically encompass station operation, antenna construction, and participation in contests and DXing. As a university-affiliated club, CUWS offers practical experience in radio theory and application, often utilizing the club callsign _G6UW_. Members learn about different modes of operation, such as CW, SSB, and digital modes, and gain hands-on experience with transceivers and associated equipment. The society's focus includes preparing members for amateur radio licensing exams and promoting ethical operating practices. Participation in CUWS provides a foundation for future involvement in the broader amateur radio community.

The N0QBH QRSS project page, a couple of projects using available kits for improved frequency and timing stability. A configurable DDS VFO 100mW transmitter with LCD display and a modified Hans Sommers 40m 100mW transmitter

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.

A 15-pin data switch, typically a rotary-knob type designed for DB-25 connectors, forms the basis for this microphone selector project. The resource details the conversion process, which involves replacing the original DB-25 connectors with **RJ-45** or **RJ-12** jacks to accommodate modern amateur radio microphones. It specifically addresses wiring for radios like the Icom IC-706 series (including the IC-7000 and IC-703) and Yaesu transceivers such as the FT-857, FT-897, FT-817, FT-7800, FT-7900, FT-8800, FT-8900, FTM-100, and FTM-400. The design ensures all microphone lines are switched straight through, with separate contacts for external speaker/headphone jacks, allowing simultaneous switching. The project emphasizes the practical application of switching between a headset for net control and a hand mic for rag-chewing without repeatedly plugging and unplugging cables. It highlights modifications to the original concept, such as eliminating a separate PTT jack by integrating PTT into headset cables and building the external speaker cable directly into the selector. The article provides guidance on managing the non-color-coded wiring often found in these data switches by soldering wires one by one from old to new connectors, ensuring correct pin alignment. This approach simplifies the conversion, making it accessible for hams seeking a functional and cost-effective mic switching solution.