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Extremely reliable FET preamplifier can handle several watts directly into either the input or the output without failure

1500 watts PEP output from a Kenwood TL-922 amplifier requires careful attention to parasitic suppression and component selection to ensure stability and longevity. This resource critically examines common modifications, often based on anecdotal evidence rather than sound engineering principles, that can degrade performance or introduce new issues. It highlights how replacing aged components often gets misattributed to the efficacy of unnecessary modifications, leading to widespread misinformation within the amateur radio community regarding amplifier stability. The article details specific, effective modifications for the TL-922, such as shortening anode-to-chassis and anode-to-grid paths to improve VHF stability and efficiency. It addresses issues like incorrect capacitor types in the tank circuit, inadequate grid grounding, and poor RF sheet metal design, providing practical solutions like adding direct ground connections for the plate tune variable capacitor. The author also discusses proper parasitic suppressor design, emphasizing the importance of lead length and component selection for optimal performance and harmonic suppression, contrasting these with less effective or detrimental 'magical suppression kits'.

DL7JV Christian report his direct experience on magnetic antennas

Dish antenna and its theory and design for high performance applications such as satellite transmission and reception as well as microwave links. Parabolic Reflector Antenna: Dish Antenna The parabolic reflector antenna which is often called the dish antenna provides an antenna solution applicable for VHF and above where high gain and directivity are needed for all type of radio communications and radio reception.

To aid in learning and improving Morse code proficiency, this resource offers an extensive collection of downloadable MP3 audio files. The content includes character practice groups, common words, punctuation, and full-length novels, all rendered in CW. Speeds incrementally increase, catering to both beginners and those aiming to build speed, with options for _Farnsworth_ spacing at lower WPM and standard spacing for higher rates. The resource also provides a Perl script, `gus_morse.pl`, allowing users to generate custom audio files from UTF-8 text. Users can download archives of sequential MP3 files, with options for English, German, Spanish, Esperanto, and Italian content. The audiobooks progress from **5 WPM** to over **40 WPM**, with some archives offering _omnibus_ collections of multiple works. The site emphasizes the importance of consistent daily practice and patient aural observation to develop procedural memory, moving beyond conscious dit and dah counting to direct character recognition. It also details the transition from Farnsworth to normal spacing, aligning with FCC and ARRL recommendations.

VE3BDB's personal page serves as a dedicated resource for members of the Radio Amateurs of Canada (RAC) residing in the Ontario South Region. Bob Cooke, VE3BDB, previously held the position of Director for this region, offering localized support and information pertinent to the RAC's activities and initiatives within Ontario South. The page likely covered regional news, events, and specific guidance for local hams, reflecting his role in facilitating communication and engagement among the amateur radio community in that area. While the page is no longer active and Bob Cooke has transitioned from his regional director role to RAC Vice President for Field Services, its original purpose was to centralize information for Ontario South hams. The content would have been tailored to address regional concerns, promote local ham radio activities, and provide updates relevant to RAC members in that specific geographic area, directing users to the main RAC website for current information.

zLog for Windows is a freeware full-featured contest logging software that runs on Windows. It supports major international and domestic (JA) contests and is customizable to many other contests not directly supported by zLog. Features include CW keying via parallel/serial/USB interfaces, highly sophisticated TCP/IP network that allows instant synchronization of a log of an M/M station, rig control, PacketCluster connenction. By JJ1MED/AD6AJ

Quarter wave omni-directional spider antenna for 2.4GHz 802.11b

The RasHAWK team has used a Raspberry Pi as the basis for a networked RF sensor capable of supporting spectrum monitoring, signal intercept and direction finding (DF) operations.

Over 130 years after its inception, Morse Code remains a fundamental skill for many amateur radio operators, enabling efficient QRP operations, DXing, and contesting. This resource provides an in-depth look at the **Koch Method** of Morse training, a widely adopted technique that emphasizes high-speed character recognition from the outset. It details how this method can significantly accelerate proficiency, moving beyond traditional, slower learning approaches. The site also delves into the rich history of amateur radio, presenting articles such as "Radio on the Rio," which chronicles local ham activity in Socorro, New Mexico. Another piece, "The Russian Woodpecker," recounts the Cold War-era efforts of hams to counter Soviet over-the-horizon radar interference on the HF bands. Furthermore, the resource explores the fascinating intersection of ham radio and radio astronomy, highlighting the direct lineage between amateur experimentation and the development of modern radio telescopes like the **Very Large Array (VLA)**. It also includes an introduction to the 6-meter band, often called "The Magic Band," detailing its unique propagation characteristics and suitability for no-code licensees seeking long-distance contacts.

The antenna described here is a direct-connect dual-rectangle beam for use on 70 cm between 440 and 450 MHz

The electrical characteristics of an antenna that are of interest to obtain by direct measurement are the frequency at which the antenna is tuned, the gain and radiation pattern

Telecom Product Profiles is a manufacturers' rep firm specializing in factory direct Nello Towers, monopoles, antenna mounts, shelters, and more. Factory direct Cellular, PCS, and Wireless Broadband equipment such as antennas, radios, and more. Installation, financing, and leasing options available.

Protecting amateur radio equipment from transient overvoltages requires robust lightning and surge protection, which is the focus of Electronic Specialty Products. The company provides various devices, including coaxial lightning arrestors for antenna feedlines and surge protectors for AC power lines and data circuits. These devices are engineered to divert high-energy surges, such as those caused by direct or indirect lightning strikes, away from sensitive transceivers, amplifiers, and computer components, thereby preventing catastrophic damage. Key products include the _Coaxial Lightning Protector_ series, designed for various impedance levels and frequency ranges up to 3 GHz, and the _AC Line Surge Protector_ for shack power distribution. Effective deployment of these protection devices can significantly reduce the risk of equipment failure and ensure operational continuity during severe weather. For instance, a properly installed coaxial arrestor can handle peak currents of **20 kA**, while AC line protectors offer clamping voltages typically below 400V. Comparing different models reveals varying levels of insertion loss and return loss, with some coaxial units exhibiting less than 0.1 dB loss at 500 MHz, making them suitable for high-performance HF and VHF/UHF operations. Integrating these components into a comprehensive grounding system is crucial for achieving maximum protection against both common-mode and differential-mode surges.

The Cumberland Valley Amateur Radio Club (CVARC) has maintained a presence since **1956**, supporting amateur radio operations in South Central Pennsylvania. This resource, while serving as a redirect, indicates the club's long-standing commitment to the hobby within its local community. It points to an updated cyberhome, suggesting ongoing activity and a desire to keep members and interested parties informed about club functions and events. The club's continued online presence, despite a website migration, highlights its dedication to fostering amateur radio. The redirect mechanism ensures that visitors can locate the current _club website_ for information on meetings, activities, and local ham radio support. Such continuity is vital for community organizations, providing a stable point of contact for hams in the Cumberland Valley region.

Mobile and Fixed-Site Radio Direction Finders

Edwin H. Armstrong's foundational contributions to radio technology are presented, including the _Regenerative Circuit_ (1912), the _Superheterodyne Circuit_ (1918), the Superregenerative Circuit (1922), and the complete FM System (1933). This resource functions as a curated collection of historical documents and artifacts, many previously uncirculated, stemming largely from the _Houck Collection_. The site's purpose is to offer these primary source materials for study and enjoyment, rather than to retell Armstrong's life story, which is covered in works like Lawrence Lessing's "Man of High Fidelity" and Tom Lewis's "Empire of the Air." The collection emphasizes original documents, photographs, and equipment, all sourced from the Houck Collection unless explicitly noted otherwise. The site is structured for browsing chronologically, by selected year, or by highlight, allowing users to explore Armstrong's technical evolution. Document files are intentionally large to preserve readability and detail, while individual pages are kept concise to optimize loading times. The content provides direct insight into the technical development of radio communications.

Examining the _Angle of Radiation_ and its impact on amateur radio operations, the resource provides insights into optimizing antenna performance for DX and local contacts. It features a design for SPOTTO, a direct conversion high-performance universal DSB transceiver, detailing its construction and operational characteristics for homebrew enthusiasts. Additionally, the site presents a 7-element VHF high-gain antenna design, offering practical schematics and expected performance metrics for those seeking enhanced gain on VHF bands. The resource also covers the development and popularity of the _FT8_ digital mode, highlighting its effectiveness in weak-signal conditions and its role in special event operations like the FT8DMC anniversary. It includes information on Hamfest India 2023 and the Lamakaan Amateur Radio Convention, providing dates and organizational details for significant Indian amateur radio gatherings. Technical articles on Direct Digital Synthesizers (DDS) VFOs and low-cost multifunctional frequency counters offer practical project ideas for radio amateurs.

A live map of current KiWiSDR receivers available on the network. It allows users to explore a directory of web-controlled receivers for listening to HF and VHF stations worldwide. The site provides access to remote ham radio stations online, making it a valuable resource for amateur radio operators.

Shows which beacon is currently transmitting on the selected radio band Displays information about transmitting beacon Informs about direction and bearing from users position towards transmitting beacon

An omnidirectional and horizontally polarized VHF antenna by EA4EOZ

Amateur radio direction finding, transmitter hunting web site from San Francisco. Triangulating a radio signal direction and plotting its bearing on a map. Hunters use doppler systems for tracking hidden transmitters anywhere in the san francisco bay area, fremont california

Over 100 amateur radio beacon audio files are presented, offering a direct auditory experience of propagation conditions across a wide spectrum of frequencies, from 1.8 MHz to 47 GHz. These recordings, primarily captured by IW3FZQ and IK3NWX, document signals from beacons such as DK0WCY, IY4M, GB3RAL, and S55ZRS, providing a valuable resource for **propagation study** and **beacon monitoring**. Each entry in the list specifies the beacon's callsign, its operating frequency in kHz, and the recording operator. This compilation includes signals from beacons located in various grid squares like JN55VF, JO44VQ, and IO91IN, illustrating diverse geographical origins. The frequencies covered span the 160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, 6m, 4m, 2m, 70cm, 23cm, 6cm, 3cm, 1.2cm, and 6mm amateur bands. Users can listen to these recordings to identify characteristic beacon tones and observe signal strength variations. The resource also invites other radio amateurs to contribute their own beacon audio files, fostering a collaborative archive of propagation data. The last update to this collection was on March 24, 2009, indicating a historical snapshot of beacon activity. Accessing the files requires the Real Player software.

About the basics of what is a discone antenna for wide band or bandwidth omnidirectional applications

Benelec Pty Ltd specializes in the design and manufacturing of **antennas** and RF components, covering a broad frequency range from 0.002 GHz to 8 GHz. Their product line includes Land Mobile Radio Antennas, such as HF 2-30MHz, VHF 40-180MHz, and UHF 200-520MHz models, alongside specialized Military Antennas for dismounted, UxS, C2, and EW applications. The company also produces Cellular Antennas, including 4G/5G and GPS/GNSS types, and Marine Antennas for both vessel-mounted and fixed-site installations. Additionally, Benelec offers a comprehensive range of coaxial cables, connectors like N-Type and SMA, and various radio accessories. The company's offerings extend to RF components such as duplexers, diplexers, and 50 Ohm loads, as well as DAS components like directional couplers and hybrid combiners. Benelec provides EMP and lightning protection solutions, including 1/4 Wave Stub protectors and replaceable GAS capsules. Their product catalog also features P25, DMR, and FM Analog radios, along with portable and mobile radio accessories like batteries, chargers, and cabled headsets. The company supports various sectors with robust communication solutions.

The North East Weak Signal Group (N.E.W.S.) website serves as the digital hub for an ARRL-affiliated regional club dedicated to _weak signal_ work across the VHF, UHF, and SHF spectrum, from 50 MHz up to light. It provides essential information for members and prospective enthusiasts, including the club's constitution and by-laws, details on officers and the board of directors, and a calendar of meetings and events. The site also features an application for membership, information on dues, and a membership roster, fostering a sense of community among its over 100 members. A significant feature of the site is its extensive archive of conference papers, including proceedings from the _Eastern VHF/UHF/Microwave Conference_ dating back to 2009. These papers cover a wide array of technical topics relevant to weak signal operations. The site also lists _50 MHz Beacons_ and _144 MHz and up Beacons_, along with links to other VHF and above resources, providing practical tools and knowledge for operators interested in pushing the boundaries of amateur radio communication.

This resource, originally intended to detail the technical specifications of the **Clover** digital communications mode, currently presents a "Page not found" error. The _Clover_ mode was designed for conveying 8-bit digital data over narrow-band high-frequency radio channels, offering robust performance under challenging propagation conditions. Its design focused on efficient data transfer and error correction, making it suitable for amateur radio operators seeking reliable digital links. The absence of the page prevents analysis of specific technical parameters, such as modulation schemes, data rates, or error correction codes that would have been presented. Historically, Clover offered significant advantages in throughput and reliability compared to earlier digital modes over HF, often achieving higher effective data rates than modes like PACTOR or AMTOR under similar signal-to-noise ratios. Without the content, a direct comparison of its performance metrics or practical application scenarios is not possible.

The NG7M Web Cluster, maintained by W7CT and NG7M, offers real-time DX spotting information crucial for amateur radio operators engaged in DXing and contesting activities. This service aggregates DX spots from various sources, presenting them in a user-friendly format accessible via both web interface and traditional telnet protocols. Operators can monitor band conditions, identify rare DX entities, and track propagation paths across multiple amateur radio bands. This cluster supports a wide range of operating modes and bands, facilitating efficient station operation for both casual DX chasers and serious contesters. The system integrates data from the Reverse Beacon Network (RBN) and PSK Reporter, enhancing its utility by providing automated CW and digital mode spots alongside manually entered voice spots. Access methods include a direct web interface for graphical display and a telnet connection for command-line interaction, catering to different operational preferences. The cluster's data stream is continuously updated, ensuring timely information for making critical operating decisions.

Aspiring radio amateurs in the United Kingdom preparing for their licensing examinations can utilize this resource, which offers mock exam questions covering the Foundation, Intermediate, and Advanced license levels. The site provides access to question pools, including associated images, designed for use with _Moodle_ learning management systems requiring PHP and MySQL. These question sets are available for non-commercial deployment by UK amateur radio clubs and organizations, facilitating local training initiatives. The original online mock test service ceased operations in August 2018 due to maintenance overhead. The current iteration serves as a repository, allowing other organizations to download the question databases. This approach enables broader access to the exam preparation material, supporting the UK amateur radio community in achieving licensing qualifications. The resource does not offer direct online testing but directs users to other sites, such as _Radio Tutor_, that implement these question banks.

Magnetic Loop Antennas for The Radio Operator with Limited Space, a two part series of articles on how to construct a magnetic loop antenna, including directions on selecting high voltage tuning capacitor

One hundred and fifty words per minute (WPM) is a configurable speed setting in this online Morse code translator, which facilitates bidirectional conversion between plain text and **Continuous Wave (CW)**. Users can input text to generate corresponding Morse code, or enter Morse code using dots and dashes to receive a text translation. The tool supports various alphabets, including Latin, Cyrillic, Ukrainian, Hebrew, and Arabic, broadening its utility for international communication. The platform offers multiple output methods for the generated Morse code, including audible playback, visual flashing, and device vibration. Advanced configuration options allow for precise control over the sound's pitch (frequency), volume, and overall speed, including a **Farnsworth speed** setting. This flexibility enables users to customize the learning or communication experience to their specific needs. Additional features include the ability to save the generated Morse code audio as a WAV file and to create shareable links for messages, which can be sent with or without the accompanying text. The interface is entirely web-based, built with HTML5 and JavaScript, ensuring broad compatibility across modern browsers.

Radio Direction Finding products

You can now build and run your own ADS-B ground station that can be installed anywhere and receive real-time data directly from airplanes on your computer

Linear Amp UK specializes in the design and production of high-quality linear amplifiers, offering models for HF, VHF, and UHF amateur and commercial applications. The company emphasizes nearly 30 years of experience in crafting each unit, ensuring robust performance and longevity. Their product line includes amplifiers engineered for a 100% duty cycle, promoting continuous and reliable operation across various modes. The amplifiers feature solid, dependable designs, ensuring quiet and effortless performance during transmission. Each unit is hand-built to stringent standards, reflecting a commitment to durability and operational stability. All products are CE approved, confirming compliance with European safety and environmental directives, and come with a standard two-year warranty, providing assurance to operators. Key specifications often include coverage for 1.8-30MHz (WARC bands), 50MHz, 70MHz, and 144MHz, utilizing tubes such as 811, 572, 811A, 572B, GS35, GS35B, 8877, 3CX1500, and _3CX1500A7_ in their designs.

Direct Conversion Receiver for Software Radio Soft66AD

An antenna for shortwave radio broadcasting consisting of rows and columns of dipoles, is a high gain directional antenna, designed for medium and long range communications.

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.

TNC-Pi is a special version of TNC-X designed to interface directly with the Raspberry Pi computer. It can connect to the Pi either via the Pi serial port, or via the I2C protocol.

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.

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.

Design for a dual-band CW transceiver using the AD9834 Direct Digital Synthesizer

Description and simulation of two types of rhombic antennas, using the software 4Nec2: the simple bi-directional and the terminated directional rhombic antenna

ITELITE manufactures omnidirectional, sector and directional antennas 900 MHz 2.4 GHz 3.5 GHz 5 GHz 5.8 GHz antennas.

This article is about a simple vertical end-fed-half-wave wire antenna for 10 meters that can be used in case of restricted space.

This resource presents a domain name for sale, Grandicelli.com, which was previously associated with an HF-VHF-UHF-SHF digital monitoring site, Wavecom Decoder tools, Winradio and DRM decoders, a WD3000 Direction Finding System, Radioraft software, and a PFSL3000 Integrated HF-VHF-UHF signal monitoring system. The current page functions as a sales portal, providing information on the domain's price of $695, with an option for a 24-month payment plan at $28.96 per month with 0% interest. The page outlines the purchasing process, including quick delivery of the domain within one to two hours, and details the transfer procedure to registrars like GoDaddy. It also highlights customer testimonials regarding the ease and speed of domain acquisition through HugeDomains, emphasizing the 30-day money-back guarantee and secure shopping experience. The resource clarifies that only the domain name is included, with hosting and web design services needing to be sourced separately.

Demonstrates the capabilities of CW_Shark, a dedicated 32-bit Windows application for Morse code operations. This software facilitates the analysis, decoding, and encoding of CW signals, providing hams with a versatile tool for various aspects of amateur radio communication. It supports four distinct modes: Decode Only, Keyboard QSO, Straight or Paddle Key QSO, and Straight or Paddle Key Practice, catering to different user needs from passive listening to active keying. Operators can utilize the Decode Only mode for signal analysis, while the Keyboard QSO mode allows for text-based interaction. The Straight or Paddle Key QSO mode offers a direct interface for traditional keying, enabling real-time communication. For skill development, the Straight or Paddle Key Practice mode provides a structured environment to hone Morse code proficiency. CW_Shark integrates essential functions for CW enthusiasts, supporting both learning and active participation in Morse code exchanges. Its focused design aims to assist operators in mastering and enjoying the art of _CW communication_.

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.

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.

The **136kHz Vertical Antenna** at G3YMC employs a Butternut HF2V structure, standing 10m tall. It integrates a 6.5mH loading coil to achieve resonance, with a matching transformer for impedance adjustment. The antenna's configuration includes top loading via a 12m horizontal wire, enhancing capacitive impedance. Initial measurements indicated a high impedance of around 300 ohms, necessitating a transformer for a 50-ohm match. Despite challenges with ground losses, the vertical antenna has shown improved performance in specific directions, filling nulls present in the previous loop antenna setup. The tuning remains broad, with variations due to environmental factors affecting the matching. Ongoing adjustments and comparisons with the loop antenna will continue to refine its effectiveness.