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SecondHandRadio.com provides a platform for the amateur radio community to buy, sell, and swap used, surplus, and obsolete electronics and electrical equipment. The site facilitates transactions for a wide range of items, including ham radio transceivers, test equipment, shortwave receivers, antennas, and vintage radio components like tubes. Users can place classified advertisements with photos at no cost, catering to individuals, radio clubs, and commercial dealers seeking to liquidate or acquire gear. The platform emphasizes ease of use with a straightforward sign-up process and no associated fees or commissions for listing or selling items. It positions itself as a primary resource for used electronics within the USA, fostering a direct connection between sellers and buyers without intermediary charges. The service supports various categories beyond amateur radio, extending to military radios and antique equipment, thus serving a broad spectrum of radio enthusiasts and collectors.

Examines Kiwa, a global entity specializing in **Testing, Inspection, and Certification (TIC)** services across diverse sectors. The resource details Kiwa's operational scope, which encompasses quality assurance, safety compliance, and sustainability solutions for industries such as Food, Feed and Agriculture, Digital and Cyber Solutions, Energy Transition, Industrial Services, and Medical Devices. It highlights the company's role in ensuring product, service, process, and system integrity through rigorous accreditation and notification processes, operating in over 35 countries worldwide. The content presents specific examples of Kiwa's engagement, such as food safety certification for HortaPronta in Portugal, explanations of the Digital Battery Passport requirements, and contributions to floating offshore wind energy development. It also outlines the company's approach to biological evaluation of medical devices according to **ISO 10993** and its commitment to ESG principles, as detailed in its online ESG magazine, Trace. The resource provides access to a certificate finder and a testing directory with over 3000 capabilities across 80 laboratories.

The _Italian VHF Beacons_ resource provides a detailed listing of active and QRT amateur radio beacons operating across VHF, UHF, and SHF bands within Italy. Each entry specifies the beacon's callsign (e.g., IQ1SP/B), operating frequency (e.g., 144.411 MHz), QTH locator (e.g., JN44VC), effective radiated power (ERP) in watts, and antenna configuration (e.g., Big Wheel, 4x Dipole, Yagi). This data is crucial for radio amateurs involved in propagation studies, equipment testing, and long-distance (DX) communication on these higher frequency bands, offering fixed signal sources for monitoring. This compilation, last updated in October 2005, serves as a historical snapshot of Italian beacon activity. For instance, it lists several 144 MHz beacons with ERPs ranging from **0.1W** to **10W**, and higher frequency beacons such as I8EMG/B on 1296.880 MHz and I3EME/B on 24192.132 MHz. The inclusion of QRT (Quiet Radio Teletype) status for many entries indicates the dynamic nature of beacon operations over time. Users can utilize this information to identify potential signal sources for band openings or to calibrate their receiving equipment against known transmissions.

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.

Temporary hf vertical installation for testing

Macintosh shareware, contains the full pool of questions for each of the five exams, and creates sample tests that will vary each time you take them and it will grade your exam.

Over two decades ago, the Kenwood TS-850S HF transceiver established itself as a robust performer, known for its excellent receiver and versatile operating features. This vintage rig, often found on the used market, continues to be a favorite among many amateur radio operators for its solid construction and reliable performance across the HF bands. Adrian's Yahoo! Group provided a dedicated forum for TS-850S owners to exchange insights, troubleshoot issues, and share modifications or operational tips. Such community-driven platforms were crucial for extending the operational life and maximizing the utility of classic transceivers, fostering a spirit of mutual aid among hams. Discussions frequently covered topics like DSP unit upgrades, common repair challenges, and optimizing the rig for contesting or DXing, reflecting the enduring interest in this particular Kenwood model.

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.

An amateur radio contest log sheet printable in A4 format, useful for portable operations, free to download PDF File.

Complete introduction to Shortwave radio, includes Qsl gallery, Propagation, Beacons, Contest, Begginers guide, in Spanish

For radio amateurs and electronics enthusiasts maintaining vintage tube gear, having accurate documentation for tube testers is crucial. Michael Marx, WB0SND, through SND Tube Sales, provides high-quality reproductions of these essential manuals. These aren't mere photocopies; each manual is digitally scanned, cleaned of imperfections, and professionally printed on a _Laserjet 5000_ with heavy card stock covers and plastic comb binding, often making them difficult to distinguish from originals. The catalog includes instruction manuals, schematics, and roll chart supplements for a wide array of classic tube testers. Operators can find documentation for popular models such as the _Hickok 539B/C_, _AVO CT-160_, and _B&K 700_, along with military-grade testers like the _TV-7_ and _USM-118_. Many listings also offer specialized supplements for obsolete or foreign tubes, ensuring comprehensive coverage for diverse tube collections. WB0SND's offerings extend to calibration instructions and data for specific adapters like the _Hickok CA-4_ and _CA-5_, providing critical support for precise tube testing.

This voice-keyer-interface connects between a Yaesu FT1000MP and a PC's sound card & COM port. It can be used as a voice-keyer with Contest Voice Blaster and as a voice-keyer and CW-keyer with Writelog.

Receiver tests of some transceivers and receivers including FT-1000, FT-2000, IC-751, IC-756 IC-7800 and TS-870

Maker of optical spectrum analyzers, digital oscilloscope, digital power meters and more test equipmente related products

NJDXA North Jersey DX Association is a platform maintained by Urb LeJeune, W2DEC, providing information about upcoming meetings, VE testing sessions, and the operation of the W2 QSL Bureau. The site offers resources for amateur radio operators in the North Jersey area to connect, share experiences, and learn from each other. It serves as a hub for DXing enthusiasts to stay updated on events and activities related to amateur radio. The intended audience includes hams in the North Jersey region looking to participate in club meetings, VE testing, and QSL bureau operations.

This page contains ideas, hints and tips about Auxiliary Items that will help you to enjoy the sport of HF Contesting without emptying the bank account

The resource, initially identified as "Alabama Radio," a dealer of amateur radios, antennas, CB equipment, scanners, and power supplies in Eastern Alabama, now redirects to a domain brokerage service. The original intent was to provide a commercial outlet for Ham Radio operators and CB enthusiasts seeking new equipment and accessories. This would have included transceivers, antenna systems, and various station components. However, the current content at the URL is _Startup Domains_, a platform for buying and selling premium .COM domain names. This shift means the resource no longer serves the amateur radio community directly. Instead, it focuses on digital asset transactions, with no mention of radio equipment, _DXing_, or _contesting_ activities. The original description of a regional radio dealer is no longer applicable to the live content.

Examines the Icom IC-2100H 2-meter mobile transceiver, detailing its operational characteristics and user experience. The review highlights the clear, easy-to-read display with internal labels, the button-filled microphone's functionality, and the rig's physical construction, including its weighty heat-sink and lack of a cooling fan. It also discusses memory programming, the unique amber-to-green backlight color options, and the radio's performance against _intermodulation_ in urban environments, noting it performs "pretty darn good" compared to other rigs. The analysis delves into a significant low-voltage cutoff problem, where the microphone ceases to function below approximately **12.6 VDC**, rendering the radio receive-only or causing it to stick in transmit. The author describes testing the voltage cutoff, observing it fluctuate from _12.38 VDC_ to 12.69 VDC. An update from Icom involved a "factory update" to the CPU's control code, which is strongly recommended for early-serial number units to prevent operational failure in low-power emergency scenarios.

Analyzing a decade of contest operations and QSLing from March 1993 to March 2003, K5ZD presents data on QSO totals by band and mode, QSL error rates, and DXCC progress. The article details the author's methodology of only answering incoming QSLs, which allowed for a study of call copying error rates, found to be between 0.8% and 1.7%. These error rates correlate with typical contest log checking reports (UBN/LCR). The data also tracks the percentage of QSOs confirmed by QSL cards annually, averaging 12.1% over the ten-year period, with a steady rate of 14-15% in earlier years. Specific statistics include a total of 215,653 QSOs logged, with 26,184 QSLs received. The article identifies the top 33 countries for incoming QSLs, accounting for over 87% of the total, with Japan, Germany, Spain, and Belgium being prominent. It also touches upon the potential of ARRL's Logbook of the World (LoTW) for instant confirmations, while noting potential error rate implications. The author's station, initially a barefoot setup with a Hygain multi-band vertical, evolved into a fully operational contest station by October 1993, utilizing DX4WIN for logging.

Makers of oscilloscopes, spectrum analyzers, frequency counters, power supplies and more testi equipment products

Explore this high-resolution ITU Zones Map, a critical reference resource for amateur radio operators, international broadcasters, and telecommunications engineers. Originally established by the International Telecommunication Union – Radiocommunication Sector (ITU-R) Broadcasting Services Division (1999), this chart accurately divides the globe into 90 specific CIRAF zones. This authoritative visual guide is indispensable for planning High Frequency (HF) radio propagation, scheduling international broadcasts, and verifying locations for radio contests and awards. Distinct from the 40 CQ Zones, the ITU zoning system provides the official administrative framework used for global frequency management. This digitally enhanced version ensures maximum clarity of zone boundaries and numbering (e.g., Zone 28 for Central Europe), making it an essential tool for technical accuracy in logbooks and station management. It serves as a trustworthy standard for educators, hobbyists, and industry professionals alike.

Demonstrates the construction of a custom programming cable for Yaesu VX-7R and VX-5R handheld transceivers, enabling computer interfacing for memory management and frequency coverage adjustments. The resource details a six-transistor circuit design, powered by the computer's RS232 interface, utilizing readily available and inexpensive discrete components. It includes a complete bill of materials, specifying transistors like the _2N2222_ and _2N3906_, diodes, and resistors, along with a matrix board layout for compact assembly within a 75x50x25mm enclosure. The guide provides practical tips for working with matrix board, such as scoring and snapping, track cleaning, and component soldering order. It outlines the specific connection requirements for both the VX-7R (via Yaesu's CT-91 breakout lead with a 2.5mm stereo jack) and the VX-5R (via CT-44 or a four-section jack), detailing signal and ground pinouts. The author successfully tested three circuits, documenting the one with complete two-way communication, allowing users to program their rigs with software like _VX-7 Commander_ and achieve capabilities beyond commercial cables, including band adjustments.

Testing SWR on your antenna and getting the best performance from your investment by L.D. Blake, VE3VDC

Online shop for all electronics needs. Cables, Buzzers all kind of electronic components capacitors, inductors, relays, resistors crystals transformers, hardware like knobs screws nuts and washers, opto electronics, diodes and transistors, soldering desoldering products, test equipmemt and tools

Application for the Apple Macintosh computer that provides a CW contesting interface for the popular MacLoggerDX loggging software. FKeyer runs on MacOS X and uses an external keyer such as the MicroHam CW keyer.

Various configurations of the Z Match Tuner are tested for power efficiency over a wide range of antenna load conditions

Special test lead that converts your regular DC voltmeter to a RF reading voltmeter

Ideas and notes on designing a SO2R radio shack room. Includes lots of radio shack pictures used by K8ND as ideas to plan his new radio shack, with contesting in mind.

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

The X80 multi-band HF vertical antenna, a commercial iteration of the Rybakov design, exhibits a physical length of 5.5 meters, or approximately 18 feet, and is constructed from aluminum tubing. It operates as a non-resonant vertical, requiring an external antenna tuner for impedance matching across its intended operating frequencies. The antenna's design incorporates a 1:4 UNUN at its base, facilitating a nominal 50-ohm feed point impedance for the coaxial cable. Performance observations indicate effective operation on 40 meters, 20 meters, 15 meters, and 10 meters, with reduced efficiency on 80 meters and 160 meters due to its relatively short electrical length for these lower bands. Comparative analysis with a G5RV dipole and a half-wave end-fed antenna reveals the X80 offers a lower take-off angle, beneficial for DX contacts, particularly on the higher HF bands. Field tests conducted with an Icom IC-706MKIIG transceiver and an LDG AT-100ProII autotuner demonstrate the X80's ability to achieve acceptable SWR across 80m through 10m. The antenna's compact footprint and ease of deployment make it suitable for restricted spaces or portable operations, though its performance on 80 meters is noted as a compromise compared to full-size resonant antennas.

Free windows morse code learning program. Whether you want to learn Morse code from scratch, never having heard a dit in your life, or you just want to speed up your copy for CW contesting, CW Teacher will help

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.

Sams continues the tradition with the publication of new manuals every month, covering the latest in Televisions, including HDTV, Projections TVs, and coming soon, LCD monitors.

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.

Presents the _K7AR DX NorthWest Web Cluster_, an online service for amateur radio operators to access real-time DX spots. The resource functions as a web-based interface, enabling users to monitor current band activity, identify rare DX stations, and track propagation conditions across various amateur bands. It aggregates spotting data, making it accessible without requiring a dedicated telnet client, thus simplifying access for many hams. The cluster integrates with the broader DX spotting network, offering a continuous stream of reported contacts. While specific performance metrics are not detailed, such web clusters typically update spots within **seconds** of submission, providing timely information crucial for DXing and contesting. Its utility lies in offering a quick, browser-based overview of the airwaves, comparable to traditional telnet clusters but with enhanced accessibility.

HF Radio Contesting and personal information: Latest scores, station tour, DL contest records and large photo section, maps and software

Test equipment maker, digital oscilloscopes, generators and counters, multimeters, logic probes testers and more

PSK31 News, Contests, Information, Forum, and more Find a helpful community and information.

Toronto Surplus , antique radio, test equipment, rf parts

The collinear J-Pole, often known as the Super-J, does improve the behavior over a regular J-Pole. As many attest, there is an advantage when vertically combining 1/2 radiating sections to have a bit of separation between the half-wave end points. The Super-J has very little separation between the two half-wave radiators.

Look for free manuals (download) in amongst paid offerings for test equipment manuals. The freebies page also has mostly ham material. We do also sell major ham collections at pretty much close to our production and distribution costs.

The South African Radio League (SARL) serves as the national representative body for amateur radio in South Africa, holding membership in the International Amateur Radio Union (IARU). It actively promotes the hobby, coordinates national amateur radio activities, and provides essential services to its members, including advocacy for spectrum allocation and regulatory liaison with ICASA. The organization frequently publishes updates relevant to the ZS amateur community, such as "HF Update with ZS4BS" and reports on events like the "ZS6STN Field day." SARL supports various aspects of amateur radio, from contesting and DXing to technical experimentation and emergency communications. The league's website lists upcoming events and news, ensuring members stay informed about national and international amateur radio developments. Its focus encompasses all amateur bands, with recent updates highlighting HF activities. The league's digital presence, including its canonical URL _mysarl.org.za_, provides a central hub for South African hams. The site frequently updates with news, event schedules, and technical information, reflecting an active and engaged amateur radio community.

The East Tennessee DX Association (ETDXA) is an amateur radio club that welcomes all experience levels. They focus on a variety of activities including DXing (long-distance communication), contesting, and general ham radio topics. Their goal is to create a community of radio enthusiasts who can learn from each other and enjoy the hobby together. They also aim to promote the art and science of DXing while representing East Tennessee on the international amateur radio scene

Web Morse Runne is an online CW (Morse code) contest simulator developed by DJ1TF - Thomas Fritzsche. This tool allows users to practice their Morse code receiving and sending skills in a simulated contest environment. Key configurable parameters include CW speed, with options ranging from 300Hz to 900Hz, and RX bandwidth, adjustable from 100Hz to 600Hz. Users can also set a monitor level and simulate various band conditions. The interface includes counters for calls and QSOs per hour, along with a timer. Pre-defined function keys are available for common contest exchanges such as F1 (CQ), F3 (TU), F6 (B4), F7 (?), and F8 (NIL). The simulator is designed for ham radio operators looking to improve their CW contesting proficiency.

A complete test report on Icom IC-7851 obtained with some lab tests, in a 21 pages pdf file.

A system designed to automatically tune small transmitting magnetic loop antennas, particularly beneficial for **contest operations** where rapid frequency changes are common. The core of the system involves a PC-based control application, AutoCap, written in C#, which monitors antenna SWR via an external meter and commands a motor interface to adjust the loop's variable capacitor. The software is compatible with Windows and Linux via the Mono framework, offering a graphical user interface for monitoring system status, SWR, power, and motor commands. Key components include one or more magnetic loop antennas equipped with DC or stepper motors for capacitor adjustment, an SWR meter with data output (such as the Telepost LP-100A or a homebrew serial/USB SWR meter), the AutoCap PC software, and a motor interface. The most effective motor interface utilizes an **Arduino-based controller** with custom firmware, providing precise control over both simple DC motors and stepper motors, and supporting features like motor braking for finer adjustments. The system allows for configurable SWR thresholds, pulse widths, and motor effort settings to optimize tuning speed and resolution. Optional radio integration provides frequency hints, enabling the algorithm to learn the relationship between motor actions and resonant frequency, thereby speeding up initial tuning responses. The software also supports antenna profiles, allowing operators to save and recall specific configurations for different loops, including accumulated frequency hint data.

A simple coax cable tester built based on the KG0ZZ project.

Showcasing a range of precision-engineered Morse code paddles, UR5CDX emphasizes craftsmanship in both dual and single paddle designs. Each key, such as the _Eridan MX_ or _CT 73 MB_, is engineered for optimal performance, catering specifically to the needs of CW operators. The paddles are not merely tools; they reflect the artistry inherent in ham radio equipment, with options for personalization like _Callsign engraving_ and _3D nameplate_ tags. The commitment to quality is evident in the materials used and the precision of the mechanics, ensuring reliable operation during contests or casual QSOs. Yury, UR5CDX, also engages with the community, sharing insights on the manufacturing process and the impact of current events on production timelines, fostering camaraderie among operators who appreciate the nuances of Morse code communication.

Frequency counter project. It includes quite a number of useful testing features which were very useful when building other projects

The _TA Callbook_ provides a dedicated online search utility for Turkish amateur radio operators, enabling users to query a database of over 15,500 records. This resource allows for lookups based on a callsign, operator's name, surname, city, or even a specific address keyword. It serves as a practical tool for DXers and contesters seeking to identify or verify Turkish stations, facilitating QSLing and contact logging. The interface is straightforward, requiring only a single keyword input to initiate a search. Operators can also update their personal information through an integrated editing form, ensuring data accuracy within the system. The platform's data collection practices are noted to comply with Turkish Personal Data Protection Law No. 6698, specifically Article 28, Paragraph 2, Clause b, by utilizing publicly disclosed information. The database was last updated on March 6, 2026, reflecting ongoing maintenance by its creators, _TA3AK_ and _TA8A_, who collaboratively developed this essential Turkish callbook.