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N4PY Software is your source for high quality, effective rig control software for your transceiver. N4PY offers rig control software for a wide variety of receivers from the Elecraft K3 to the Ten Tec RX 320 receiver and it is major equipment integrator supporting panadapters, winkeyer, Tmate2 or FlexControl

SWR (standing wave ratio), is a measurement of how efficiently your antenna system will radiate the power available from your radio. In simple terms, your radio would like to radiate all of its power, but can only do so if the other components cooperate

From TenTec Inc a video that illustrate a PL-259 installation on a RG8X coax cable

About the clemens match for beam antenna, as an alternative to common gamma matching techniques

Live DX spots are presented through a _web cluster_ interface, utilizing both a world map and a Google Maps display for visualizing amateur radio propagation. The system provides real-time spotting data, enabling operators to track active stations globally. Users can observe current band conditions and station activity, which is crucial for optimizing contact strategies across various amateur bands. The platform's utility extends to contest operations and general DXing, offering a visual representation of where stations are being heard. While the primary function is DX spotting, the site also includes technical articles, such as instructions for interlocking two Flex Radios for single-transmitter compliance in contests, and a guide for constructing a simple **5KW** 1:1 balun for **160m/80m** dipoles using RG400 cable. This combination of live data and practical technical content supports both operational awareness and station improvement.

Filter design software. A program designed to expedite the design and analysis of lowpass (and highpass) filters with nearest 5% component values. SVCfilter is 32-bit Windows electrical filter design software nicely written to help the radio amateur, technician or engineer design and analyze lumped-element lowpass and highpass filters.

Demonstrates the construction and implementation of a **two-element phased vertical array** for 40 meters, utilizing _Christman phasing_ techniques. The author, W4NFR, details the process from building individual 1/4-wave aluminum verticals to integrating them into a phased system. The resource covers antenna spacing of 32 feet, elevated radial design, and the critical steps for tuning each vertical to achieve a 1.1:1 SWR before combining them. It also provides insights into calculating precise coax lengths for feedlines and the phasing delay line, emphasizing the use of an MFJ-269 Antenna Analyzer for verification. The finished system exhibits good front-to-back nulls, with an overall SWR ranging from 1.6:1 to 2.2:1, which is managed by an antenna tuner. The project includes detailed photos of the relay box, showing 12 VDC relays capable of handling 5KV, and the control box in the shack for switching between three different antenna pattern configurations. Static bleed-off chokes are incorporated for protection, and the construction emphasizes robust weatherproofing for outdoor elements.

Sherwood Engineering Inc. (SEI) offers a repository of technical presentations and white papers focused on optimizing amateur radio transceiver and receiver performance. Content includes detailed analyses of _roofing filters_, transmitted IMD, and receiver characteristics, with specific discussions on products like the Drake R-4C and Icom IC-781. Presentations from events such as Dayton Contest University (2008-2014) cover topics like "How To Optimize Rig Performance," "Transceiver Performance: 10 Years of Change," and "Choosing a Transceiver: Far from Simple." Additional white papers address HF mobile antenna efficiency, ground screen alternatives to buried radial systems, and common receiver problems with solutions. The site also provides historical product information for items like the SE-3 MK IV synchronous AM detector and various 455 kHz mechanical and crystal filters, though many products are no longer in production. Receiver test data and alignment tips for the R-4C are also available, offering insights into rig modifications and performance enhancements.

Guide to ground mounting antennas, notes on efficiency, elevated installations, metal towers and masts, other mounting schemas, moble homes and rv, lightning protections, artiche by Bencher

This calculator is designed to give resistor values for unbalanced T-pads, and for balanced H-pads.

Showcases the Del City Amateur Radio Club (W5DEL), an organization serving the amateur radio community in Del City, Oklahoma. The club facilitates local ham radio activities and provides a platform for members to connect. It emphasizes community engagement through various events and resources, supporting the interests of local operators. The club's online presence, while functional, appears to be a repurposed template, with some content not directly relevant to amateur radio. Members can access information on club dues, upcoming events, and community guidelines. The site mentions a focus on VoIP, suggesting an interest in **digital voice modes** and **internet-linked radio systems**. Although specific technical projects or operating achievements are not detailed, the club aims to foster camaraderie and provide a local point of contact for hams in the Del City area.

Green that aluminum into something useful right in your own backyard by WB2CQM

The Remote Control Antenna Switch consists of two circuit boards. The control unit and the remotely controlled switch

Antenna dimension, diagram and simulation of the ZX Antennen ZX 6-6 Yagi for VHF UHF by DF9CY

Showcasing a specialized product line, Advanced Receiver Research presents a comprehensive catalog of **low noise preamplifiers** and microwave **Gunnplexers**. The offerings span a broad spectrum of radio frequencies, from VLF, LF, MF, and HF bands up through VHF, UHF, and microwave, catering to diverse applications including amateur radio, commercial installations, and military systems. Their product range includes mast-mount preamplifiers, inline attenuators, power dividers, and various coaxial components. My own experience with similar low-noise front ends for weak-signal work on 2 meters and 70 centimeters underscores the critical role such components play in maximizing receiver sensitivity, especially when chasing distant DX or engaging in EME. The detailed product descriptions and technical specifications provided on the site allow operators to select the optimal preamplifier for their specific band and noise figure requirements, essential for improving signal-to-noise ratio. The site also lists specialized products for unique applications like Nuclear Magnetic Resonance (NMR) and Studio Transmitter Links (STL), demonstrating a depth of engineering capability beyond typical amateur radio fare. This breadth of offerings, coupled with clear ordering and warranty information, positions Advanced Receiver Research as a key supplier for high-performance RF components.

Operating on the 11-meter band, the Alfa Tango Argentina website serves as a digital hub for CB radio DX enthusiasts, particularly those affiliated with the _Alfa Tango_ international group. The resource primarily functions as a community portal, facilitating connections among members and promoting activities related to long-distance CB communications. It presents basic information about the group's presence in Argentina and emphasizes the social aspect of radio communication, framing participants as "friends who have never met." The site's content reflects the operational focus on **DXing** within the CB radio sphere, a practice that mirrors amateur radio's pursuit of distant contacts. While specific operational data or technical guides are not detailed, the site's existence supports the organizational structure of the Alfa Tango group, which coordinates activities across various countries.

Measurements for building a full wave loop using wire

The page, focuses on **TVRO** (Television Receive-Only) satellite systems, specifically addressing C-band and Ku-band reception. It covers technical aspects of digital video broadcasting, including **DVB** and MPEG-2 standards, relevant to satellite television enthusiasts. Content includes discussions on Digicipher 2 and 4DTV systems, which were prominent in North American satellite television at the time. The resource also references the South Scanner Satellite Services Chart (SSSSSC), a tool for identifying satellite transponders. While primarily about commercial satellite TV, the underlying principles of satellite signal reception and digital modulation have tangential relevance to amateur radio satellite operations.

This resource details the four primary functions of a ground system: lightning energy dispersion, equipment safety, RF return path provision for end-fed antennas, and management of induced RF currents. It clarifies that a ground system's effectiveness varies depending on its specific function, noting that a good lightning ground might not be an effective RF ground. The content emphasizes that proper antenna system design, including baluns and appropriate feedline lengths, often negates the need for an RF station ground to mitigate common mode currents or RFI in the shack. The article quantifies lightning energy, stating its peak is in the dozens or hundreds of kilohertz, with damaging energy extending to hundreds of megahertz, and currents reaching thousands of amperes. It recommends solid, wide, smooth copper surfaces for ground leads to achieve low impedance across a wide frequency range. The author, W8JI, shares practical insights from his station, which includes two 300-ft towers and four 130-ft wire verticals, detailing his use of common point grounds and _DX Engineering RR-8 HD_ antenna switches for lightning protection without coaxial surge protectors. Specific examples of antenna systems prone to common mode current problems are listed, such as random wire antennas without proper feedline lengths and off-center fed dipoles. The text also explains how a ground screen or radial system can reduce local noise sensitivity for vertically polarized antennas by covering the lossy earth.

Decoding NOAA APT weather satellite images is achieved with a homebrew receiver and a Turnstile Cross Dipole antenna, feeding data to a Pentium-3 500MHz PC running Windows XP and the WXTOIMG program. This setup, operated by VU2IIA in Mumbai, India, focuses on capturing and processing signals from NOAA satellites to generate visual weather data. The blog documents the technical aspects of constructing the receiving station, including antenna design and receiver integration. It provides insights into the practical challenges and successes of amateur satellite reception, specifically for Automatic Picture Transmission (APT) signals. Operational details cover the software configuration and image processing workflow necessary to transform raw satellite data into usable weather imagery. The content serves as a practical guide for radio amateurs interested in satellite meteorology.

Presents a Brazilian online portal dedicated to **amateur radio**, **CB radio**, and shortwave listening (SWL) communities. The platform facilitates free classified advertisements for radio equipment, including HF, VHF, and UHF transceivers, antennas, and accessories. It also aggregates a substantial collection of technical articles from Brazilian amateur radio operators (e.g., PY2DJW, PY1LJ, PY1LL/4LC), covering topics such as CW training with RufzXP, balun importance, and radio wave characteristics. Furthermore, the resource provides extensive links to Brazilian ham radio sites, clubs, international organizations, and official ANATEL (Brazilian National Telecommunications Agency) documents regarding licensing, equipment homologation, and regulations. The portal features sections for user evaluations of transactions, a "Top Ten" list of most visited pages, and a calendar of past and upcoming ham radio events across Brazil, including "Feirinhas" (local swap meets) and "Encontros de Radioamadores" (hamfests). It also includes a directory of ham radio related businesses and services in Brazil, such as antenna manufacturers (Diex), QSL card printers (Arte Final), and repair technicians (PY2MOK). The site also offers propagation maps, DX cluster links (e.g., DX-SUMMIT), and satellite tracking tools, making it a central hub for Brazilian radio amateurs seeking to buy, sell, learn, or connect with the community.

The Yaesu FT-1000MP Mark-V, introduced at Dayton 2000 Hamvention, features a higher RF power of **200 W PEP** and a Class-A amplification SSB mode at 75 W. Key enhancements include an _Interlocked Digital/Analog Bandwidth Tracking system (IDBT)_, a Variable Front-End Filter (VRF) preselector, and improved ergonomics, notably a multi-function shuttle jog dial. This model, a successor to the 1996 FT-1000 and FT-1000MP, was designed to compete with high-end transceivers, despite its retail price of $4200 initially. The transceiver's physical dimensions are 406 x 135 x 348 mm (16 x 5.3 x 13.7 inches) with a weight of 14 kg (31 lbs), making it substantial. Its rear panel offers over 20 connections, including power, external DSP speaker, BAND DATA I/O, ALC, and multiple interface jacks for DVS-2, Packet, and RTTY. The unit also provides two keyer inputs, a DB9M serial interface for CAT, and two PL female antenna connectors, plus additional receive antenna jacks. Despite its advanced internal architecture, including two independent receivers with their own IF filters and AGC loops, the display technology, utilizing fluorescent discharge rather than LCD, contributes to an older aesthetic. The control panel is extensive, featuring 92 knobs and buttons, alongside numerous LED indicators for various modes and functions.

We are committed to constantly improving our solutions in areas of GPS System, GPS Receivers, GPS Antennas, GPS Dataloggers, RF Modules, Wireless Security Systems, Automatic Vehicle Location (AVL) for real time and passive tracking

A small antenna tuner for 14 MHz

The antenna was built to be used for shortwave listening with a Tecsun PL-660 radio receiver. Later it was used with Yaesu VX-6 handheld transceiver and with Yaesu FT-817ND for shortwave listening.

The RoadTrek design presents some unique challenges to us hams. Here an example of a VHF and HF antenna installation on a VAN

Competent all-around 2-meter mobile transceiver, review by W4TI

Enhanced SSB Audio (ESSB) is a specialized operating mode that extends the capabilities of traditional Single Sideband (SSB) voice transmissions. This presentation by K4QKY delves into the technical aspects of ESSB, discussing its advantages and the ongoing debates within the ham radio community regarding audio quality and bandwidth usage. ESSB aims to provide clearer and more natural-sounding audio, which can enhance the overall communication experience for operators. The presentation covers various topics, including microphone selection, audio processing techniques, and the importance of proper equalization. It also addresses the controversies surrounding ESSB, such as the potential for interference and the debate over whether it strays too far from traditional SSB practices. By understanding these elements, amateur radio operators can make informed decisions about their audio setups and contribute to discussions about the future of SSB operations.

The 10-minute, 25-second video demonstrates making a QSO via the VO-52 amateur radio satellite, focusing on real-time Doppler shift correction. It features Simon, 2E0HTS, operating a Yaesu FT-847 transceiver and a homebrew dual-band Yagi antenna, specifically a 10-element 435 MHz Yagi for uplink and an IO Loop for 145 MHz downlink. The video visually details the operator's technique for continuously adjusting the uplink frequency to compensate for the satellite's changing velocity relative to the ground station, a critical aspect of successful satellite communication. The demonstration highlights the practical application of Doppler compensation, showing the operator tuning the transmit frequency to maintain a stable received signal from the satellite. This approach contrasts with systems employing automatic Doppler correction or full-duplex operation, providing insight into manual frequency management for satellite passes. The video serves as a direct, observational guide for hams interested in LEO satellite operations, particularly those using non-tracking, manually tuned setups.

Here is a well documented plan of a 20m-10m compact magnetic loop antenna. Article includes lots of pictures and technical details published by KP4MD

Whith more than 20 years of ham practicen SWL Thierry LOMBRY, alias ONL5183, has written several technical pages about ham activities, including propagation, radio perturbations, radioastronomy, DXing, QSLing, ham-spirit, review of material and more. This very interesting website is completed by a large French section devoted to amateur astronomy illustrated with vivid colors pictures.

Pegasus RX-320 and other N4PY software for tentec radios

Some basic antenna information for the newcomer

How to build a phasing harness for stacking antennas

The Receiver Test Data resource is a detailed review database focusing on the performance metrics of various radio receivers. The methodology involves rigorous lab measurements, often adhering to standards such as the ARRL RMDR (Reciprocal Mixing Dynamic Range) and BDR (Blocking Dynamic Range). Specific test equipment and protocols are utilized to assess parameters like noise floor (dBm), AGC threshold (uV), and LO noise (dBc/Hz). For example, the _Icom IC-7300_ is evaluated with a noise floor of **-133 dBm** and an LO noise of **-141 dBc/Hz**, providing insights into its performance under different operational conditions. The resource includes a wide range of models, from the _Elecraft K3S_ to the _Yaesu FTdx-101D_, each tested for dynamic range, sensitivity, and selectivity. The data is sorted by key metrics such as third-order dynamic range and phase noise limitations, with RMDR values calculated by subtracting 27 dB from LO noise figures. This structured approach allows users to compare different receivers' capabilities, focusing on technical specifications and performance outcomes in various scenarios. DXZone Focus: Review Database | Lab Measurements | -133 dBm | ARRL RMDR

This page is dedicated to amassing information on the Tentec/Globe Wireless RX-321/RX321

Heathkit Icom Kenwood Power Transistors Ten Tec Yaesu spare Hamradio parts.

The resource details the construction of a homebrew 50-watt FET amplifier, based on Don W6JL's _QST Homebrew contest_-winning design from 2009. It functions as an afterburner for QRP transceivers, providing a **12dB** power lift. The amplifier utilizes IRFZ24N FETs and covers the 80, 40, 30, and 20-meter bands, with the 20m LPF extending to 17m. Key technical aspects include an FT37-43 transformer for the input network, a relay-switched 3dB pad for lower bands controlled by an _Arduino Nano_, and an RF-actuated T/R switch. The LPF board integrates four relay-switched filters rated for 50 watts, using capacitors with a minimum 250VDC rating. Performance measurements indicate a power gain ranging from **4.4dB** on 20m to 8.1dB on 80m, with a required drive power of approximately 5 watts. The article also discusses thermal management, current limiting considerations, and component sourcing.

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.

Construction of attenuator, suitable for fox hunts at 144mhz

TenTec 1208CY 10/50 MHz Transverter modification by DF9CY

EggsHam is a PalmOS application that generates (and grades) _practice_ amateur radio licensing exams. It is for people interested in obtaining an amateur radio license in the US, who want to practice for the Technician, General, or Extra written exam.

The GM4JJJ VHF and EME pages document David's extensive work in Earth-Moon-Earth (EME) communication, specifically on the 144 MHz band, and his involvement in amateur radio astronomy. The resource details his station setup and operational experiences, providing insights into the technical challenges and rewards of bouncing signals off the moon. It offers a glimpse into the specialized equipment and techniques required for successful EME contacts, a niche but highly rewarding aspect of amateur radio. David's content shares practical applications and field results from his EME endeavors, which can be particularly useful for hams contemplating or actively pursuing moonbounce operations. The information, while not a step-by-step guide, implicitly compares the complexities of EME with more conventional VHF/UHF operations, highlighting the significant power and antenna gain necessary to overcome path losses. This resource serves as a testament to the advanced capabilities achievable in amateur radio.

General article on Baluns at myantennas.com, what is a balun and when to use baluns

Tests on a preamplifier for 50 MHz installed right at the feedpoint of the antenna.

Demonstrates various practical amateur radio projects and technical discussions through video episodes. One episode details cutting and retuning a _1/4 wave shorted stub_ from 101.7 MHz to 107.5 MHz to safeguard a transmitter's driver stage, alongside insights into advanced _160-meter antenna systems_ like eight-circle arrays and beverage antennas. Another segment covers upgrading firmware on an _ATS-20+_ receiver using AverDudes for improved display and functionality, and a detailed guide on using D-Star DR mode on an _ICOM ID-52A_ for international repeater programming. Additional content includes a deep dive into _OpenHamClock_ as a potential replacement for the HamClock project, updates on _Raspberry Pi 5_ running Trixie OS, and a review of the Choyong LC90 Internet radio with AI integration. The series also features "Ham College" episodes, which meticulously prepare viewers for the Technician Exam by covering topics such as antenna and transmission line measurements, SWR interpretation, and the functions of basic electronic components like rectifiers, relays, and transistors. Practical advice on coaxial cable characteristics, dummy loads, and proper soldering techniques is also provided.

Guglielmo Marconi's foundational contributions to wireless communication began in 1894, inspired by Heinrich Hertz's discovery of radio waves in 1888. His initial experiments at his family home near Bologna quickly demonstrated signal transmission beyond line-of-sight, achieving distances up to **two miles** within a year. Marconi secured a patent in 1896, subsequently gaining interest from the British Admiralty after disinterest from the Italian government. By 1899, Marconi's system facilitated transmissions across the Bristol Channel (nine miles) and the English Channel (31 miles). A pivotal moment occurred in 1901 with the successful _transatlantic transmission_, defying the prevailing belief that Earth's curvature would limit practical range to approximately 200 miles. This achievement catalyzed the rapid development of the wireless industry. Marconi continued refining his inventions and, in 1909, shared the _Nobel Prize_ in physics with Karl Ferdinand Braun for their advancements in radio technology.

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.

After you have build this antenna, you may not need anything else. This article shows how to build a VHF j-pole antenna and how to protect it by inserting it into a PVC tube, the correct way.