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Accurate frequency measurement is crucial for amateur radio operators, particularly when building or troubleshooting transceivers and test equipment. This resource details the construction of a _PIC microcontroller_-based frequency counter, providing a practical solution for precise frequency display. The design incorporates an LCD readout, offering clear visual feedback of measured frequencies. The counter can operate as a standalone unit, useful for general bench testing, or be integrated directly into a receiver. Its built-in offset functionality allows for seamless integration, enabling the display of the received signal frequency rather than the intermediate frequency. The project focuses on accessible components and construction techniques, making it suitable for homebrew enthusiasts. Key features include a measurement range up to **50 MHz** and a compact form factor.

Mitigating RF noise in a mobile operating environment, particularly within a _Jeep TJ_ vehicle, presents unique challenges due to the vehicle's electrical system and chassis characteristics. This resource details practical methods for identifying and suppressing various forms of radio frequency interference (RFI) that can degrade receiver performance for both CB and amateur radio transceivers. It covers common noise sources such as ignition systems, alternators, fuel pumps, and computer modules, explaining how these components generate broadband or specific frequency noise that impacts radio communications. The guide offers actionable solutions, including proper grounding techniques, the strategic use of ferrite beads and toroids on power and data lines, and the installation of bypass capacitors. It discusses the effectiveness of different filtering strategies for DC power lines and antenna feedlines, illustrating how a clean power supply and shielded cabling can significantly reduce conducted and radiated noise. The information presented helps operators achieve a lower noise floor, improving signal-to-noise ratio and enabling clearer reception of weak signals, which is crucial for effective mobile DXing or local ragchewing.

The resource details the construction of a multiband trap-style Inverted-V antenna designed for operation on 3.5 MHz, 7 MHz, 14 MHz, 21 MHz, and 28 MHz. It presents specific winding data for the traps, including the number of turns, wire gauge, and coil former dimensions, crucial for achieving resonance on the target bands. The document provides a parts list and a diagram illustrating the antenna's physical layout and trap placement. It outlines the process for building the traps using PVC pipe formers and specifies the required capacitor values for each trap. The design emphasizes a practical approach to achieving multiband operation with a single feedline, a common goal for HF operators with limited space. The document includes a table with antenna segment lengths for each band, allowing for precise replication of the design. It also offers insights into tuning and adjustment, ensuring the antenna performs optimally across the designated amateur radio bands.

Hi-Z Antennas offers specialized high-impedance receiving systems, primarily focusing on phased vertical arrays for HF reception. Their product line includes preamplifiers designed for shortened vertical antennas, featuring optimized 15dB gain and array-matched characteristics. These components are engineered to enhance weak signal reception and improve signal-to-noise ratio across the HF spectrum. The company provides controllers for managing multiple vertical elements in a phased array configuration, enabling directional reception patterns. These systems are particularly effective for mitigating local noise and interference, a common challenge in urban and suburban operating environments. Specific offerings include solutions for 160-meter and 80-meter bands, addressing the unique requirements of low-band DXing. Technical details often reference components like the 2N3866 transistor in preamp designs and discuss concepts such as out-of-band attenuation. The focus remains on optimizing receiving antenna performance through impedance matching and active amplification, rather than transmit capabilities.

Over 45 years of dedicated work by Robert Sherwood, NC0B, culminated in a wealth of technical insights, particularly concerning **receiver performance** and the intricacies of transceiver design. The site provides access to numerous presentations from events like Dayton Contest University and W4DXCC, covering topics such as optimizing rig performance, the evolution of lab testing, and the impact of roofing filters on transmitted IMD and receiver characteristics. These resources offer detailed analyses and practical advice for serious operators and contesters. While product manufacturing, including the SE-3 MK IV synchronous detector and various Drake R-4C accessories like roofing filters and cooling kits, has ceased, the legacy of technical documentation remains. The site details specific products like the Icom IC-781 and R-9000, and offers insights into 455 kHz mechanical and crystal filters, along with DSP protection strategies. Crucially, the site features extensive receiver test data, allowing radio amateurs to compare the performance of various transceivers. This data, often presented in white papers and slide shows, includes detailed measurements and explanations of key performance metrics, serving as a valuable reference for understanding and selecting high-performance HF gear.

For radio amateurs seeking to identify or verify callsigns from Bosnia and Herzegovina, an online callbook service offers a direct search utility. This resource focuses exclusively on the _T9_ prefix, allowing users to input a specific callsign and query a dedicated database. It serves as a historical reference for contacts made prior to its last update. The utility provides a straightforward interface for callsign lookups, presenting results based on data compiled up to _July 31, 2000_. While the information is static and not current, it remains useful for confirming older contacts or for historical research within the amateur radio community. The service is maintained by _Boris Knezovic, T93Y_, offering a focused resource for this specific geographic region.

Digital radio mondiale DRM products, measuring tools, Magnetic field probes, RF power meters, Broadband loop antennas, DRM devices and services

A magnetic loop antenna for the VHF band, featuring a high gain that can be compared to a quarter wave vertical antenna

A 38-foot Tristao Tower, similar to the U.S. Tower HDX538, was installed twice by the author, first in 1980 and then reinstalled in 1989. The resource details the challenges of self-performing heavy construction tasks like breaking concrete and digging a 3' x 3' x 6' deep footing, contrasting it with hiring professionals for the second installation. It highlights the financial and physical costs associated with DIY tower foundation work, noting a rebar cage cost of $65 in 1980 versus $150-$175 today, and the expense of tools for bending rebar. The content emphasizes the critical importance of obtaining building permits, recounting how a permit in Buena Park, California, nullified a neighbor's complaint about TVI. It also discusses the necessity of adhering to local building codes, such as the 1975 UBC and the subsequent 1985 UBC recertification requirement, which reduced the allowed antenna wind loading from 30 square feet to 20 square feet for the author's _KT34A_ Yagi. The footing depth also increased from 6 feet to 6.5 feet under the newer code. Practical advice includes hiring licensed contractors for specialized work, delaying antenna installation for a month after raising the tower, and verifying buried utilities before any excavation. The author provides specific examples of utility location services like _DigAlert_ in California, underscoring the legal and safety implications of neglecting this step. The narrative is grounded in personal experience, offering a realistic perspective on tower projects.

The FieldComm Association, based in Central Virginia, operates as a specialized amateur radio club with a primary interest in emergency communications. Members engage in various technical aspects of radio, including digital modes, QRP operations, and DXing. The association provides a platform for hams to develop skills in field deployment and reliable communication under challenging conditions, often leveraging modern digital protocols. This organization's activities support the practical application of amateur radio for public service, emphasizing readiness and operational proficiency. Members collaborate on projects and share knowledge, fostering expertise in areas like portable station setup and efficient data transmission. The focus on emergency communications distinguishes its operational priorities from general interest clubs, aligning its efforts with community preparedness.

The ÖVSV website provides extensive resources for Austrian radio amateurs, including details on its nine **Landesverbände** (regional sections) and the Austrian Military Radio Society (AMRS). It features information on licensing, legal frameworks, and **band plans** for both HF and VHF/UHF operations. The site also covers various amateur radio activities such as contests (HF, VHF/Microwave, Alpe-Adria, SOTA, ARDF), technical projects like WRAN, and educational content explaining what amateur radio is and how to become a licensed operator. Recent news items highlight events like the "Laa Funk '26" exhibition, the "OE5XLM" club station's participation in the CQ WW Contest, and the "International Marconi Day 2026" activation by "OE26M" from Küniglberg. The site lists upcoming events, including a 160m OE-Aktivitätsrunde, a seminar on Baluns/Ununs, and various club meetings and flea markets. Membership is facilitated through regional sections, and the site emphasizes amateur radio's role in independent communication during crises.

An interesting article on guanella baluns that cover several aspects of homebrewing 1:1 and 4:1 current baluns by KN9B

**LDG Z100** automatic tuner repair focuses on toroid replacement and troubleshooting. The guide provides detailed steps for diagnosing and fixing common issues with the toroid, which is crucial for the tuner's performance. It includes specific instructions on disassembling the unit, identifying faulty components, and sourcing replacements. The document is technical, requiring familiarity with electronic components and soldering techniques. It emphasizes the importance of using the correct toroid specifications to ensure optimal functionality. Successful repair of the **LDG Z100** ATU restores its ability to match a wide range of antennas, enhancing transmission efficiency. The guide compares the performance before and after the repair, highlighting improvements in SWR readings and overall reliability. Practical application of this repair extends the life of the tuner, making it a cost-effective solution for amateur radio operators. The document serves as a reference for similar repairs on other models, providing insights into common issues and solutions. It is a valuable resource for those looking to maintain their equipment without resorting to professional services.

The practice of converting computer server power supplies to make a very high quality high power supply at low cost is attractive. It doesn't normally require any modification to the supply but the hard part is figuring out how to trick them into turning on.

Interesting article on how and when sleep during a contest

The **KC0KJF** personal amateur radio page provides a collection of resources for fellow hams, particularly those interested in operations within southwest Missouri. It offers detailed listings for **Missouri repeaters** on both 2 meters and 70 centimeters, serving as a practical reference for local VHF/UHF communication. The site also includes information about the operator's station setup and antenna projects, such as a dipole and a bazooka antenna, which can offer insights into basic antenna construction and deployment. Beyond local repeater data, the page features links to the FCC Part 97 rules, essential for understanding amateur radio regulations. The operator, licensed as a Technician Class since April 16, 2001, shares his journey from Citizen's Band Radio to amateur radio, driven by a lifelong fascination with shortwave listening. This narrative provides context for the resource's focus on practical operating information and foundational regulatory knowledge. Additional content covers specific equipment like the 2-meter/70-centimeter Arrow Antenna, useful for hams considering portable or fixed station VHF/UHF setups.

PZTLog is a freeware amateur radio logging application designed for Windows operating systems, facilitating rapid **QSO entry** and management. It integrates features such as DXCC statistics tracking, a built-in DX Cluster client, and support for various digital modes including PSK31, PSK63, PSK125, and RTTY. The software provides a straightforward interface for inputting essential contact details and supports real-time interaction with DX spotting networks, enhancing the operator's situational awareness during operating sessions. The application's utility extends to contest logging, offering a streamlined approach for competitive operating. PZTLog's capability to manage **DXCC awards** and integrate with digital mode operations positions it as a versatile tool for general logging and specific contest scenarios. Its design prioritizes ease of use for quick data entry, making it suitable for operators who require efficient logging without extensive configuration.

The QRPSPOTS.com domain, once a dedicated resource for QRP operators to share real-time DX spots, has undergone a significant transformation. Previously, it served the amateur radio community by providing a platform for DX spotting, including features like a telnet cluster, web cluster, JOTA cluster, and integration with RBN and PSK Reporter data. This functionality was specifically tailored to the QRP operating mode, allowing hams running low power to find and share contacts effectively across various bands. However, the current iteration of the website, as observed, no longer presents any amateur radio content. Instead, it displays information related to a Chinese educational institution, featuring sections like "About Us," "Talent Training," "Teaching and Research," and "International Exchange." The site also lists academic notices, enrollment information for international professional qualifications, and details about CPA and ACCA project classes. This shift indicates that the domain has been repurposed, moving away from its original ham radio utility. The Four State QRP Group, which previously sponsored the QRP Spots service, is no longer associated with the content presented on this URL.

For radio amateurs and electronics enthusiasts requiring specialized wiring solutions, Multi/Cable Corporation provides custom multi-conductor cable manufacturing services. They focus on made-to-order constructions, offering a broad range of specialty cable products including composite, instrumentation, electronic, flexible cord, thermocouple, high-temperature, and Mil-Spec wire and cable. Their capabilities extend to extensive customization of all cable components, ensuring precise adaptation to specific application requirements, which can be critical for bespoke shack setups or antenna control lines. With over 50 years in business, Multi/Cable emphasizes low minimum orders, quick turnarounds, and competitive pricing, making custom cable solutions accessible even for smaller projects. A case study highlights their role in helping an emergency vehicle lighting company expand offerings by providing versatile and cost-effective wire bundles, demonstrating their ability to support diverse technical needs beyond typical off-the-shelf options. They also provide reference data and guides on choosing conductors, insulation, and jacketing materials.

Presents the construction of a 2-meter **Skeleton Slot Yagi** stack, detailing the design process and practical considerations for VHF operation. The author shares insights from building and testing this antenna, emphasizing its performance characteristics for local and extended range contacts. The project outlines the specific dimensions and materials used, providing a clear path for other radio amateurs to replicate or adapt the design for their own stations. The resource covers the unique aspects of the Skeleton Slot radiator, explaining how its geometry contributes to gain and pattern control. It includes discussions on impedance matching and feedline considerations crucial for optimizing power transfer and minimizing SWR. The article draws on real-world testing, offering practical results that validate the theoretical design. This project serves as a valuable reference for those interested in custom VHF antenna solutions.

Presents a detailed resource for DXers interested in Non-Directional Radiobeacons (NDBs), MF, HF, and VHF propagation beacons, and various other radiobeacon types. The site offers access to downloadable information files, including an Abbreviations List, NDB List Country List, and NDB Publications List, which serve as foundational materials for newcomers to the hobby of beacon monitoring and DXing. It covers specialized topics such as DGPS beacons, GMDSS DSC mode, and NAVTEX mode, with dedicated sections providing in-depth explanations. A Beacon Photo Gallery showcases diverse radiobeacon types from around the globe, offering visual context for different systems encountered in the field. The platform also facilitates participation in unique monthly Coordinated Listening Events (CLEs), providing guidelines and schedules for these activities. The resource outlines various associated Groups.io lists, including the primary NDB List for radiobeacons (NDBs, Propagation Beacons, VOR systems), the DGPS List for DGPS DXing, Time Signals, LORAN, and WeFAX modes, and specialist groups like NavtexDX and DSC List for GMDSS-DSC. It details how to join these communities for further engagement and information exchange.

Operating a modern amateur radio station often involves integrating various software tools, and LogHX aims to provide a unified environment for Windows users. The software facilitates comprehensive QSO accounting, allowing operators to track contacts and manage both e-QSL and traditional paper QSL exchanges, including via QSL managers or direct methods. It also offers real-time QSO preview and integrates with popular callbook data for quick lookups. LogHX supports various logbook database searches and maintains statistics for numerous awards, a critical feature for serious DXers and contesters. The program handles logbook import and export in widely used formats such as _ADIF_ and _Cabrillo_, ensuring compatibility with other logging applications. Furthermore, it interoperates with Telnet clusters and third-party ham radio software, enhancing its utility in a networked shack environment. Key functionalities include antenna rotator control, editable macros for PSK, RTTY, CW, and SSB operations, and CAT control via _OmniRig_ or direct interfaces. Embedded modules like MMVari, MMTTY, and CWServer streamline digital mode operations, while its multi-window structure allows users to customize their screen layout, preserving valuable monitor space.

Pictures and description of a SteppIr vertical antenna setup in a small backyard using DX Engineering radial plates.

This resource provides a unique historical audio archive of 50 MHz DX contacts, documenting significant F2 and Es propagation events experienced by PA2S (formerly PA2HJS) since 1978. The collection includes recordings of beacons and two-way QSOs with stations across North America, South America, Asia, Australia, Europe, and Africa. Specific entries detail contacts with rare DX entities such as ZS6PW, VE1AVX, C5AEH, J52US, TR8CA, LU8MBL, VK8ZLX, and various Japanese stations, often noting the mode (SSB or CW) and propagation type. The archive also highlights challenging pile-up situations and frustrating near-misses during major openings. The recordings, initially in RealAudio format for solar cycles 21 and 22 and later in MP3 for cycle 23, offer a practical illustration of 6-meter band conditions over several solar cycles. The content allows hams to listen to actual signals from different continents, observing signal characteristics like typical TEP fading from 5H3RA or strong F2 backscatter from OZ1BVW. It provides a comparative perspective on propagation effectiveness between solar cycles, noting that cycle 23, while not as robust as previous cycles, still yielded interesting openings. The archive serves as a valuable educational tool for understanding real-world 50 MHz DXing and propagation phenomena.

TSC International produces soft magnetic sheet steel, custom-stamped and heat-treated to achieve optimal electrical characteristics for applications such as motors, generators, linear power supplies, and ballasts. The company's manufacturing process focuses on precise material engineering to meet specific performance requirements in various electrical systems. They also specialize in soft magnetic core materials essential for transformers, chokes, and inductors. These core materials are utilized in power supplies, lighting ballasts, signal conditioning circuits, inverters, and battery chargers, providing critical magnetic properties for efficient energy conversion and signal integrity. Located at 39105 Magnetics Blvd, Wadsworth, IL 60083-0399, TSC International provides contact via sales@tscinternational.com or phone at +1 (0) 847 249 4900, facilitating direct inquiries regarding their magnetic component offerings.

An comprehensive article on 40 meters antenna comparing vertical height to the resulting gain

An interesting article on choosing the right battery when operating in portable mode, considering charging time and modes, weight and size.

Manually programming D-Star handheld transceivers like the _Icom ID-51A_ and _ID-31A_ can be a straightforward process, enabling operators to configure repeaters, simplex frequencies, and D-Star specific settings without relying on computer software. This method is particularly useful for field operations or when quick adjustments are needed, allowing hams to set up callsign routing, DR mode, and reflector links directly from the radio's interface. Understanding the menu structure and key sequences is crucial for efficient on-the-fly programming. Operators often find manual programming invaluable for activating new D-Star repeaters encountered during travel or for participating in local nets where specific G2 or G3 gateway configurations are required. While software like _CS-51_ offers convenience for bulk programming, the ability to manually input frequencies and D-Star parameters ensures operational flexibility. This approach also helps hams troubleshoot connectivity issues by verifying individual settings directly on the transceiver, ensuring proper D-Star registration and gateway access.

Demonstrates a range of specialized radio frequency equipment and consulting services for amateur and professional applications. The offerings include _Vector-Finder_ direction finding antennas, various test equipment such as _gate dip meters_ and RF sniffers, and communications receiving adjuncts. Additionally, the company produces satellite antennas for weather satellite reception, voice amplification devices like the _Flex-Mike_, and custom prototype circuit boards. The company's product line addresses needs for precise RF measurement, signal detection, and specialized antenna systems, particularly for direction finding and satellite communications. Their historical association with National Radio (HRO) suggests a legacy in radio technology. The site also highlights a subsidiary, Sierra Mountain Products, which offers outdoor recreational gear, indicating a diversification beyond core RF manufacturing.

Approximately 190–209 words of content are available, including previously unreleased **radio intercepts** from the Russian army during the Battle for Kyiv, with confirmed authenticity. The platform provides extensive news coverage, video reports, and analytical content focusing on Ukraine and international affairs, frequently publishing exclusive materials. Recent articles cover topics such as emergency power outages in Kyiv, discussions on Iran's nuclear program, and Belgium's policy regarding temporary protection for children born after Russia's full-scale invasion. The site also features in-depth investigations into Russian military losses, the political isolation of Hungary within the EU, and mental health advice for coping with wartime stress. Timely updates are provided throughout the day, detailing events such as drone incidents in Lithuania and proposed restrictions on military personnel's access to gambling in Ukraine. The platform offers a variety of multimedia content, including video and photo reports on events like the double explosion in Bucha and search operations for victims of the Volyn tragedy. Editorial selections delve into topics such as parliamentary elections in Slovenia, internal political conflicts in Ukraine, and the export of Ukrainian drones to the Middle East, alongside historical analyses and opinion pieces from various contributors, often featuring expert commentary and reader engagement. The content is primarily focused on current events and geopolitical analysis, with a strong emphasis on the **Ukrainian conflict**.

A vertical antenna project for the 7MHz made with some spare parts. Based on a broken 20 foot fishing pole, it is based on a good ground system made with radials and a capacitive hat done to increase the global radiation resistance of the antenna. A custom loading coil is also included in this project to perfectly tune the antenna to the CW portion of the 40 meters band.

The **Solarcon A99** vertical antenna, a half-wave over a quarter-wave variable mutual inductance design, primarily serves the 11-meter CB band but also finds use on 10 and 12 meters for amateur radio operators. Its simple construction, consisting of three fiberglass sections and a 16 AWG radiating element, makes it an accessible option for new operators or those seeking an easy-to-install base station antenna without complex mounting requirements. Despite claims of 9.9 dBi gain being widely considered exaggerated, and a manufacturer rating of 2000 watts power handling often viewed with skepticism (with 300 watts suggested as a practical limit), the A99 maintains popularity due to its low cost and ease of deployment. It typically tunes to a 1.2-1.3 SWR out of the box, requiring minimal adjustment via its two tuning rings. Its high angle of radiation allows for effective local communication even when mounted at low heights, such as 8-10 feet off the ground. However, the A99 is known for significant RF bleed-over issues, particularly when operated with higher power or mounted close to residential electronics. While its internal design is often described as cheap, the antenna exhibits remarkable durability, frequently lasting a decade or more in various weather conditions. Its affordability and straightforward setup continue to make it a go-to choice for many radio enthusiasts.

The function of the XPhase is based on the fact that the interfering signal, received by an auxiliary antenna, is added phase-shifted to the signal received from the main antenna. When the phase-shift is more or less 180°, the interfering signal is canceled out.

During a club's "Filetto Day" event, a comparative field test was conducted between a **Buddipole** antenna and a homemade 20/40-meter wire dipole. The author, IW5EDI, performed this personal evaluation from a mountain top at 1500 meters above sea level, utilizing a Yaesu FT-857D transceiver to switch between antennas. The observations on the 20-meter band indicated that the wire dipole consistently delivered significantly stronger signals compared to the Buddipole. Additionally, the Buddipole exhibited higher levels of **QRM** during the listening tests. The commercial Buddipole, known for its multiband capability and compact size with a self-supporting tripod, was contrasted with the simpler, larger wire dipole, which required a fiberglass fish pole for support. This direct comparison highlights practical differences in performance and deployment between a popular portable commercial antenna and a basic wire antenna in a real-world operating environment.

Demonstrates a specialized **DX cluster** designed to support the annual Jamboree On The Air (JOTA) event, facilitating real-time spotting for participating Scout stations. While its web interface has been discontinued due to security concerns, the cluster remains fully operational and accessible through standard cluster software. Operators can connect to the JOTA cluster by pointing their client to www.pi4raz.nl on port 7300. This setup allows for the exchange of **DX spots** and other operational information relevant to JOTA participants, ensuring that Scouts and their amateur radio mentors can continue to make contacts and log stations during the event.

Key facts about how to solder, how to solder wire, how to solder pcb's, and including general soldering techniques and the best ways of making good solder joints for electronic circuits and construction. Includes video

Batterytech supplies NiMH, NiCd, and Li-ion battery packs, chargers, and analyzers, catering to a range of portable electronic devices including Ham Radio handheld transceivers. The product line supports popular amateur radio brands such as _Kenwood_, _Icom_, and _Yaesu_, providing power solutions for their portable models. Offerings extend to batteries for CB radios, scanners, and other two-way communication equipment, ensuring operators can maintain field operations. The inventory includes specific battery eliminators and replacement packs designed to meet the power requirements of various handheld radios. Customers can find suitable power accessories for digital cameras, PDAs, and cellular phones, alongside specialized batteries for Nextel radios. The focus is on providing reliable power sources for critical portable electronics.

The 9W2VVH blog documents the amateur radio journey of Hussairy, focusing on his station setup and operational experiences from Malaysia. Content includes details about his _Yaesu FT-857D_ transceiver, which serves as the primary rig for HF, VHF, and UHF operations, often paired with a _G5RV_ antenna for HF bands. The site also features discussions on various aspects of ham radio, such as antenna experimentation and QSL card exchanges, reflecting a hands-on approach to the hobby. Operational updates frequently cover DX contacts and local ragchews, providing insights into propagation conditions and operating techniques from Southeast Asia. The blog serves as a personal log and sharing platform, showcasing the practical application of amateur radio equipment and fostering connections within the global ham community.

The Icom AH-4 autotuner operates efficiently across multiple HF bands, providing seamless automatic tuning for antennas from 3.5 MHz to 54 MHz. Its robust design allows for outdoor installation, making it suitable for field operations and fixed stations. The unit interfaces with Icom transceivers via a control cable, enabling automatic band switching and tuning. The AH-4 is capable of handling up to 120 watts of RF power, ensuring compatibility with most amateur radio setups. Its weather-resistant casing and compact form factor make it a versatile choice for operators requiring reliable performance in diverse environments. Field tests demonstrate the AH-4's ability to maintain low SWR across its operational range, enhancing signal quality and transmission efficiency. Compared to manual tuners, the AH-4 offers significant time savings and ease of use, particularly in rapidly changing band conditions. Its integration with Icom radios simplifies operation, eliminating the need for manual adjustments. The autotuner's performance is consistent with other high-end models, providing a cost-effective solution for amateur operators seeking dependable tuning capabilities without sacrificing performance.

Constructing a high-power 70cm solid-state amplifier presents unique challenges, particularly when aiming for 500 watts output using modern LDMOS devices. This resource details the author's experience building a 70cm amplifier based on a _Freescale MRFE6VP5600H_ transistor, initially from an RFHAM kit. It meticulously outlines the necessary modifications to achieve advertised performance, including optimizing input and output matching, correcting bias circuitry, and ensuring proper output balun connections for stability. The author shares specific adjustments, such as trimming the prototyping board for better transistor fit, drilling additional mounting holes for improved heat sinking, and replacing original matching capacitors with a single _20pf MIN02 metal mica_ for superior output. A critical fix involved jumpering gate decoupling pads to balance the push-pull transistor halves, which increased output to 580W and improved IMD. The resource also highlights a crucial correction to the output balun connection, initially reversed in the _Dubus_ article schematic, which resolved intermittent stability issues. Test results are provided, showing input power, output power, and drain current at 50V, demonstrating the amplifier's performance after modifications. This practical account offers valuable insights for hams undertaking similar high-power UHF amplifier projects, especially those working with LDMOS devices and kit-based constructions.

A DIY Automatic Band Decoder (ABD) project, designed for dual-radio operation, addresses the common challenge of integrating band data with older transceivers lacking dedicated outputs. This particular build utilizes an AVR AT90S8515 microcontroller and a 16x2 Liquid Crystal Display (LCD) to provide band information, specifically targeting Kenwood rigs via a computer's LPT port. The design aims for cost-effectiveness while maintaining functionality, offering a solution for hams seeking to add automatic band switching capabilities to their station without significant expense. The project outlines the core components required, including the microcontroller, LCD, and an enclosure, noting that the Printed Circuit Board (PCB) fabrication and AVR programming might present challenges for some builders. It details the input requirements, such as a four-pin input and PTT for each radio, along with a 13.8V DC power supply. The decoder provides 2x6 outputs capable of sinking 500mA, suitable for controlling external devices like antenna switches or filters. Despite the original unit being damaged by a lightning strike in 2004, the author confirms its successful operation prior to the incident and mentions plans for a revised version. The resource includes a schematic in PDF format and images of the finished PCB and assembled unit, demonstrating the practical implementation of the design.

Examines JPS Communications' product offerings, focusing on their contributions to Radio over IP (RoIP) and Push-to-Talk over Cellular (PoC) technologies. The resource details how JPS solutions enhance Land Mobile Radio (LMR) capabilities by providing secure and cost-effective methods for communication expansion and interoperability. It highlights the company's 30-year history in developing infrastructure to make communication systems more versatile, secure, and robust, addressing critical needs in various operational environments. The content specifically outlines JPS gateways that bridge traditional radio systems with PoC solutions, facilitating seamless communication across disparate technologies. It also describes multiple approaches for expanding LMR coverage beyond conventional system limitations. The information presented underscores the practical application of these technologies in achieving communications interoperability, irrespective of the underlying systems or protocols, aiming to improve operational efficiency and safety.

Is a group who enjoy gathering together to practice the hobby of Amateur Radio.

Details the construction of an **HF converter** designed by M1GEO, George Smart, specifically to extend the frequency range of the FunCube Dongle Pro (FCD) for amateur radio reception. The FCD natively covers 64 to 1,700 MHz, but this project enables reception from 0 Hz to 64 MHz by up-converting signals to the FCD's operational range. It employs a **double-balanced mixer** with a 100 MHz local oscillator (LO) to translate incoming HF signals; for instance, a 1 MHz signal appears at 101 MHz within the FCD's passband. The design incorporates a 7th-order Chebyshev low-pass filter with a 62 MHz cutoff frequency at the input to mitigate image frequencies, ensuring cleaner spectral presentation. George provides the schematic, PCB masks, and Gerber files for replication, noting that Far Circuits also offers PCBs. The resource includes test results for the low-pass filter and measurements of LO leakage, identifying -36.8 dBm at 100 MHz as a potential sensitivity concern. M1GEO discusses potential improvements, such as adjusting the mixer's LO drive, adding a balance pot, or incorporating a post-mixer high-pass filter to reduce LO breakthrough. Audio recordings from 40m and 17m demonstrate the converter's performance with WRplus SDR software.

Presents Eagle Stainless Tube & Fabrication as a certified distributor specializing in various tubing products essential for antenna construction and other amateur radio projects. It details their offerings, which include aluminum tubes in fractional, metric, and heavy wall specifications, alongside stainless steel bar stock in round, square, and flat profiles. The resource highlights the availability of a diameter sizing chart and direct contact options for specialists, indicating a focus on providing specific material dimensions and expert support for custom fabrication needs. The company emphasizes its role as a supplier of raw materials, crucial for hams engaged in DIY antenna builds or structural components for their shacks. Their inventory supports the precise mechanical requirements often encountered in radio frequency engineering, where material strength, weight, and corrosion resistance are critical design factors for outdoor installations. The site primarily serves as a product catalog and contact point for sourcing specialized metal tubing and bar stock, providing technical specifications and material grades relevant to robust amateur radio infrastructure.

There are many designs for building preamps each with their own advantages and disvantages. In this PDF Article author reviews several different types.

Approximately 2.8% annual decline in Australian amateur radio licenses was observed over the five years leading up to 2002, a trend that prompted further analysis of the country's amateur population. This resource examines licensing statistics and demographic shifts within the Australian amateur radio community between 1998 and 2007, utilizing available data to identify patterns in license issuance and renewal. The study focuses on **population trends** and the underlying factors contributing to changes in the number of active **amateur radio operators**. It provides insights into the health and growth trajectory of the hobby in Australia during this specific period. Understanding these demographic shifts is crucial for clubs, regulatory bodies, and equipment manufacturers to adapt strategies and foster engagement.

Presents the **BayCom** packet radio system, detailing both its hardware and software components specifically designed for amateur radio use. The resource offers insights into the technical specifications and operational aspects of the BayCom modem, which has been a staple for many German packet radio enthusiasts. It covers the integration of these components within a typical amateur radio station setup, enabling reliable digital communication. Further, the site provides a broader context by including general information about the German packet radio network. This encompasses network topology, operational protocols, and historical developments relevant to packet radio in the region. Users can find details on how to connect to and utilize the existing infrastructure, fostering participation in the local digital amateur radio community.

Established around 1968, the Wichita Amateur Radio Society (W.A.R.S.) N5WF provides a central hub for amateur radio operators in the Wichita Falls, Texas area. The society actively supports local ham radio interests, fostering community engagement and technical development among its members. W.A.R.S. is known for its commitment to public service communications and promoting the amateur radio hobby through various activities and educational initiatives. The society's activities often include field operations, technical presentations, and participation in emergency communications drills, which align with its mission to support the amateur radio community. Members frequently engage in _DXing_ and _contesting_, sharing their experiences and knowledge to help others improve their operating skills. The club also maintains local repeaters, providing essential infrastructure for regional communications.

Presents a construction project for a 1:1 current balun, specifically detailing the _Sorbie Balun and Bottle Choke_ design. The resource outlines the winding technique, employing 4+4 turns of mini coaxial cable on a large ferrite core, and provides insights into the physical assembly. It includes specific material recommendations, such as the type of ferrite and coaxial cable, crucial for achieving the desired impedance transformation and common-mode current suppression. The content covers the practical steps involved in building the balun, from preparing the coaxial cable to securing the windings on the ferrite toroid. It also discusses the integration of the balun into an antenna system, emphasizing its role in maintaining pattern integrity and reducing RF interference in the shack. The resource offers a clear, step-by-step approach, making the project accessible for homebrewers. Illustrations and photographs accompany the text, visually guiding the builder through each stage of construction. The article concludes with performance expectations and considerations for deployment, ensuring the constructed balun functions effectively across the intended frequency range.