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Before the advent of digital transmission modes, several analog schemes were developed to transmit images or image-like information on the Amateur Radio bands.

Missouri USA

RTTY transmissions with audio boards, can be transmitted either in FSK or AFSK mode. Learn differences between this two different modes by IK3QAR

This antenna was conceived mainly for high-speed digital transmission via satellite. The antenna is made of two full waves loops , mounted at right angles to each other. Then coupled together, 90 degrees out of phase over a horizontal circular reflector. With this configuration the antenna is omni directional and circularly polarized.

Details Amphenol's extensive product line, encompassing electrical, electronic, and fiber optic connectors, alongside coaxial and flat-ribbon cable solutions. The company designs, manufactures, and markets these interconnect systems globally, serving various communication network requirements. Their offerings support end-to-end connectivity, crucial for modern broadband infrastructure. Emphasizes the company's role as a major provider of components vital for reliable signal transmission in diverse applications. Products like _LMR(R) coaxial cables_ and various _RF connectors_ are essential for amateur radio installations, ensuring low loss and robust connections for antennas and transceivers. The focus on high-performance interconnects directly benefits hams constructing or upgrading their stations. Amphenol's broad portfolio includes specialized connectors and cable assemblies, meeting rigorous technical specifications for both commercial and amateur radio use.

Award series "Castles of Poland" are issued for two-way QSO or SWL-report with radiostations working from castles being on territoy of Poland.

Presents the full owner's manual for the _Drake R-4C_ communications receiver, specifically a late version edition. This resource outlines the comprehensive operational instructions, covering everything from initial setup and tuning to advanced features and controls. Hams can reference detailed diagrams and explanations for proper signal reception across various amateur bands. The manual includes critical information for alignment procedures, ensuring the receiver performs to its optimal specifications. It details the steps required for calibrating the internal circuitry, which is essential for maintaining sensitivity and selectivity over time. My experience with vintage Drake gear confirms the value of these original documents for accurate adjustments. Furthermore, the document provides insights into troubleshooting common issues and performing routine maintenance. It serves as an authoritative guide for anyone operating or servicing this classic piece of amateur radio equipment, helping to preserve its functionality for years of DXing and ragchewing.

This resource indicates that the specific page detailing the RockMite QRPp Rig CW transceiver project, previously hosted by WY3A on QSL.net, is currently inaccessible. The QSL.net platform, which provides free web hosting services to over 30,000 amateur radio operators and organizations, confirms the file or page no longer exists. Users are advised to attempt direct contact with the website owner or utilize an internet search to locate the content. The platform's error message clarifies that QSL.net support cannot assist in finding individual missing pages due to the decentralized maintenance of its numerous hosted sites. It encourages reporting any missing files related to the QSL.net main site itself. Donations are encouraged to support the free email and web services provided to the amateur radio community.

The Vintage Radio and Phonograph Society (VRPS) is a non-profit historical organization, incorporated in Texas, serving enthusiasts in the Dallas-Fort Worth area and surrounding regions. Its core mission revolves around the **preservation** and **restoration** of antique radios and phonographs, fostering a community for those with a general interest in early wireless technology and vintage audio equipment. The society actively supports the new radio/TV museum in Kilgore, TX, demonstrating its commitment to broader historical preservation efforts. Members engage in activities such as "Show and Tell" days, where they bring items for discussion, and participate in an annual convention. Events like the Spring Auction and the 2026 VRPS Convention, scheduled for October 23-25 at the Grapevine Convention Center, provide opportunities for members to connect, share knowledge, and acquire vintage pieces. The organization also highlights related events, such as the Houston Vintage Radio Association's 2026 convention.

Learn Morse Online in 40 lessons with this web based morse code learning program, based on the Koch method. Choose the lesson, adjust the wanted parameters, and start the transmission of a set of random characters based on chosen lesson. Recognize the code and verify it at the end of the lesson.

In order to determine total distance that a transmission may be received by two elevated antennas, we must add together the radio horizon distance of both antennas.

Amateur Television (ATV) operations involve transmitting and receiving live or recorded video and audio signals over amateur radio frequencies. Unlike narrow-band modes, ATV utilizes a wider bandwidth to convey video information, often requiring specialized transceivers, antennas, and signal processing equipment. This mode allows hams to share visual content, demonstrate projects, or conduct video conferences, typically on VHF, UHF, and microwave bands due to the bandwidth requirements. The SwissATV resource focuses on the technical aspects and community engagement surrounding ATV within Switzerland. It covers topics relevant to setting up ATV stations, understanding signal propagation at higher frequencies, and participating in local ATV activities. The site serves as a central point for Swiss ATV operators to exchange knowledge and coordinate transmissions, fostering the growth of this specialized amateur radio mode.

Operating in the **microwave** spectrum, Response Microwave, Inc. specializes in the design and manufacturing of RF and microwave signal processing components and subsystems. The company's product line encompasses a wide array of offerings, including Connectivity Series components, rotary joints, phase shifters, cable assemblies, surge protectors, terminations, Hybridline/Couperline products, circulators/isolators, directional couplers, quadrature hybrids, attenuators, custom assemblies, filters/diplexers, DC blocks & bias tees, power dividers/combiners, laser diodes & drivers, high-frequency connectors, and precision test accessories. This extensive catalog supports various applications requiring precise signal manipulation and transmission at elevated frequencies. The resource provides access to a comprehensive product catalog and a dedicated connector catalog, detailing specifications for components like **high-frequency connectors** and test cables. While specific performance data or comparative analyses are not directly presented on the main page, the breadth of products indicates a focus on providing foundational building blocks for microwave systems. The company emphasizes customer service and aims to be a reliable source for RF/Microwave/Optics product requirements, serving a growing customer base with its specialized component offerings.

How to handle feedline radiation issues

An home made remote antenna tuner project that with a 6 meter random wire and two radials of about the same length, can tune from 40 to 10 meters without any issue.

This software is an amateur radio utility for the lookup of an FCC issued Amateur Radio Call Sign. Run on Windows Linux and MacOSX

Monitoring extremely weak signals in the QRSS (Very Slow Morse) mode requires specialized receiving and processing capabilities to extract information below the typical noise floor. This project provides a software solution, _QrssPiG_, designed to run on a Raspberry Pi, enabling it to function as a dedicated QRSS grabber. It interfaces with various Software Defined Radio (SDR) devices, including the popular _rtl-sdr_ dongles and _HackRF_ units, to acquire raw I/Q data streams. The software then performs the necessary signal processing to visualize and decode these faint, long-duration CW transmissions, often operating with milliwatts of power. The system leverages the computational power of the Raspberry Pi for real-time signal analysis, allowing hams to participate in QRSS experiments and monitor distant beacons. It supports different SDR hardware, offering flexibility in setup and deployment for home stations or remote monitoring sites. The project includes detailed instructions for installation and configuration, making it accessible for those familiar with Linux environments. This grabber is particularly useful for tracking propagation on the LF and HF bands where QRSS activity is common, providing a visual representation of signal presence over extended periods.

Approximately 30 active members comprise the _Racine Megacycle Club_, W9UDU, a long-standing amateur radio organization based in southeastern Wisconsin. The club provides a local hub for hams interested in various aspects of the hobby, including contesting, DXing, and technical experimentation. Regular meetings offer opportunities for knowledge exchange, project collaboration, and social interaction among licensed operators. The club actively participates in public service events and promotes emergency communications preparedness within the community. They often host field day operations, providing hands-on experience with portable setups and demonstrating the capabilities of amateur radio to the public. Membership is open to all licensed amateur radio operators. Their website serves as a central point for club news, event announcements, and contact information, supporting the club's mission to advance the art and science of amateur radio.

Warszawa 2000 Award, Mazowsze (Mazovia) Award, Vistula) River Award, All Baltic Islands Award, Maritime Mobile award, Baltic Sea lighthouses award

Greek Lighthouse Award has been instituted by the Northern Greece Contest Team and will be issued to any Ham Radio operator or SWL for QSOs with (or reports from) amateur radio stations operating from Greek's lighthouses.

Examples of absorbtive low-pass filters in which the unwanted high-frequency energy is separated from the wanted output and then dissipated in matched resistors

Clay County Missouri

The Australian Ladies Amateur Radio Association (ALARA) was formed in 1975 with a mission to encourage women's interest and active participation in amateur radio.

Lighthouse list, dx peditions, pictures and awards issued

Long-delayed echoes are radio echoes which return to the sender several seconds after transmission.

Since 1946, VK6 Weekly News has delivered weekly broadcasts to amateur radio operators across Australia, particularly in the VK6 region. The broadcasts include news updates, acknowledgments of contributors, and calls for operators to engage by transmitting news or submitting stories. This initiative strengthens community ties among amateur radio enthusiasts and encourages collaboration in maintaining the network of repeaters. The broadcasts reach various states, including Western Australia, Queensland, and New South Wales, ensuring that information is disseminated widely. VK6 Weekly News emphasizes the importance of operator contributions, thanking them for their efforts in sustaining the amateur radio community. Accessible through multiple platforms, it supports ongoing amateur radio activities and development in the region. Operators are invited to participate actively, enhancing the richness of the news content and fostering a collaborative spirit within the amateur radio community.

Hellgate Amateur Radio Club W7PX - Missoula Montana

Delta Electronics Manufacturing, a global manufacturer, specializes in _RF connectors_, adapters, and cable assemblies, providing custom interconnect solutions with superior performance. Their Advanced Vertically Integrated (AVI) global facilities emphasize efficiency, quality, flexibility, and cost control across their product lines. The company serves diverse industries, including broadcast and audio, test and measurement, military, aerospace, and public safety communications. For instance, Delta supplies RF interfaces for military aircraft, satellite launch vehicles, and missiles, maintaining a long-standing QPL supplier status. Their field-tested RF interconnects are also crucial for two-way radios, base station equipment, and antenna systems in public safety applications, ensuring reliable performance in critical communication infrastructure. Delta's solutions extend to commercial aircraft and semiconductor manufacturing, where their RF interconnects power etch equipment, deposition equipment, and chip testing systems worldwide.

The PI6ATV repeater, operating on 10.475 MHz, serves the amateur television community by providing both analog and digital DVB-S2 services. Recent updates include user-adjustable Symbol Rate settings via Webcontrol, allowing operators to optimize their digital ATV transmissions for various conditions. This functionality, implemented on December 13, 2022, enables dynamic configuration of the digital stream. Significant technical milestones include the return of the analog ATV transmitter on 10.475 MHz, featuring a newly constructed liquid-cooled final amplifier by Edwin PD2EBH. This restoration on September 6, 2020, followed an 18-month hiatus, ensuring continued support for traditional analog ATV enthusiasts. The repeater's transition to DVB-S2 modulation, initiated on December 20, 2018, addressed capacity limitations of the previous DVB-S setup. This change from 20 MS/s with FEC 3/4 to DVB-S2 allowed for more efficient data handling, accommodating multiple channels within the available bandwidth and enhancing the overall digital ATV experience.

A home made magnetic loop for HF Bands. This small and compact loop is designed to support small power transmissions on HF bands, from 7 MHz to 21 MHz

Whatch at beacons transmitting in real time. This page contains a self refreshing table that displays every 10 seconds the current transmission schedule of the international beacon project. Tune your radio and check the beacon you are hearing.

An Easy Guide to UI-View32 and UISS produced by Mineo Wakita, from installing UI-View32, setting up and configuring software and using the UISS

The ISSB System operates on 14.332 MHz, 365 days of the year.

The K5BSA Venturing Crew 73 resource, intended for a ham radio club based in Richardson, Texas, currently presents a 404 "Page Cannot Be Found" error. This status indicates the original content, which likely detailed club activities, membership information, or amateur radio projects, is no longer accessible at the specified URL. The page provides general information about _QSL.net_ hosting services, noting it supports over 30,000 websites for amateur radio operators and organizations. The error message suggests contacting the website owner directly or using an internet search to locate the intended content. It also clarifies that QSL.net cannot assist in finding specific missing pages hosted by individual users, as each site is independently maintained. The platform offers its email and web services without cost to the amateur radio community. Despite the error, the page includes links to general QSL.net resources such as "About QSL.net," "The Help Page," and "EMail Mailing Lists." It also features a prominent "Make a Donation" option, emphasizing that while services are free, user contributions are encouraged to support the hosting infrastructure.

The San Bernardino Microwave Society, operating under the callsign _W6IFE_, serves as a significant technical hub for amateur radio operators specializing in frequencies above 1 GHz. This organization's influence extends across Southern California, providing a centralized resource for advanced RF experimentation and **regional frequency management** within the microwave spectrum. Its permanent value lies in its extensive archive of technical papers and project documentation, which are critical for operators engaged in high-frequency design and deployment. The society's infrastructure is primarily intellectual, focusing on the dissemination of specialized knowledge rather than a conventional repeater network. It offers a robust collection of technical papers from prominent members like K6PIP, K6BLG, and WA6EXV, covering topics such as Rubidium oscillator data, logging software, and filter design. This resource facilitates advanced amateur radio operations, including participation in microwave contests and the development of custom transverters for bands like 24 GHz. The site also details various member projects, such as the Owens Valley Radio Observatory Project, showcasing practical applications of **RF propagation analysis** and system integration. DXZone Focus: Microwave | Technical Papers | RF Propagation | Contest Results

The EA8ALP personal page, hosted on QSL.net, is currently inaccessible, presenting a 404 "Page Cannot Be Found" error. This resource was intended to feature Adelto, an amateur radio operator from the Canary Islands, likely detailing his station, operating activities, or other personal ham radio interests. The QSL.net platform, which hosts over 30,000 amateur radio websites, provides free web and email services to operators and organizations, relying on donations for support. While the specific content of EA8ALP's page is unavailable, the platform's structure suggests it would typically include information relevant to **DXing** and **contesting**, common interests for operators in geographically desirable locations like the Canary Islands. Users encountering this error are advised to contact the website owner directly or use an internet search to locate the intended content, as QSL.net cannot assist with individual site content issues.

Ham radio transmissions can interfere with television reception. This is called television interference, or ham radio TVI. Consumer adoption of cable television has significantly reduced ham radio TVI. But the introduction of IPTV, or television over phone systems, has brought ham radio TVI back, often with a vengeance. Here's why

Demonstrates MegaPhase's extensive product line of RF and microwave coaxial cable assemblies and components, engineered for demanding applications up to 110 GHz. Key offerings include _Test & Measurement Cables_ with superior phase and amplitude stability, _RF & Microwave Cables_ utilizing _GrooveTube®_ technology for high power systems, and a range of RF components like directional couplers and power dividers. The site details specific cable types such as _Alumibend™_ for space-qualified, ultra-light applications through 90 GHz, and armored cables designed for rigorous environments up to 50 GHz, emphasizing their robust mechanical strength and measurement repeatability. The resource highlights applications across diverse sectors, including space programs like the _Hayabusa_ mission, global security (C5ISR), military airborne systems (MIL-T-81490), telecom, and automated testing. It also provides technical insights through "How To" guides on measuring amplitude/phase stability vs. flexure and proper connector cleaning. The company's commitment to quality is underscored by its rigorous testing protocols and a strong warranty, ensuring reliable operation in critical systems.

The resource, "Conventional Use of Transmission Line," meticulously details the operational principles of transmission lines, emphasizing the Transverse Electromagnetic (TEM) mode of energy transfer. It clarifies that for a line to function purely as a transmission line, all currents must be confined internally, with external fields ideally zero. The discussion differentiates between balanced and unbalanced lines, asserting that while both require equal and opposite currents within the conductors, the key distinction lies in the voltage relationship of each conductor to the surrounding environment. It highlights that a good antenna pattern does not inherently confirm proper feeder balance, and that common-mode currents can lead to RF in the shack and increased noise levels, even without pattern distortion. The article further explains that a transmission line can become a radiating conductor if energy is applied in a non-TEM mode, leading to common-mode issues. It cites classic texts like Jordan and Balmain's "_Electromagnetic Waves and Radiating Systems_" and Kraus's "_Antennas_" to support its definitions of TEM mode operation. The content also explores non-transmission line applications of parallel or concentric conductors, such as _coaxial dipoles_ and _folded dipoles_, which intentionally operate in non-TEM modes for antenna functionality. The author, _W8JI_, stresses that simply measuring equal currents is insufficient to confirm a balanced feeder; phase and voltage balance to ground are equally critical.

RF is causing strange issues on the touch sensor buttons, controlling inputs, volume, channels on Samsung LCD TV. Solution is to disable front touch panel.

An interesting guide about APRS (Automatic Position Reporting System) and to Digipeating through the International Space Station - ISS

The video delves into the fascinating science behind antennas, which are crucial for receiving and transmitting electromagnetic waves. It explains how antennas convert electric signals into electromagnetic waves for transmission, and how they operate through the oscillation of positive and negative charges in dipole arrangements. Practical antenna implementations, such as dipole antennas for TV reception and Yagi-Uda antennas with reflectors and directors, are also discussed alongside modern dish TV antennas with parabolic reflectors for signal processing. It's a comprehensive overview of how antennas work and their significance in communication technology.

HF Net by Old Man International Sideband Society

Highlights the PRO CW CLUB's mission to foster the art of telegraphy, a fundamental skill in amateur radio. The club actively encourages members to engage in CW operation, emphasizing its historical significance and continued relevance in modern ham radio communications. Members participate in various activities designed to improve their Morse code proficiency and on-air operating techniques. The club's focus extends to supporting new operators in mastering CW, providing resources and mentorship to help them achieve comfortable speeds and accurate copy. This dedication ensures that the legacy of _telegraphy_ endures within the amateur community, connecting hams across continents with the simplicity and effectiveness of dots and dashes. The PRO CW CLUB serves as a hub for CW enthusiasts, promoting regular on-air activity and camaraderie among its members, who span the globe.

The CQ WPX Contest website provides information about the international contest based on working all prefixes, with details on dates, rules, results, log submissions, online certificates, and log checking reports. Users can also access a searchable score database, rules FAQ, and follow updates on the blog and social media. The site is a valuable resource for amateur radio operators participating in the WPX Contest.

DataBridge wireless RF modem modules facilitate point-to-point data transmission, supporting analog, digital, and serial RS232 UART signals. These modules are engineered for robust wireless communication, offering a reliable solution for various industrial and amateur radio applications requiring secure data links. The product line includes specific models designed for different frequency ranges and power outputs, ensuring compatibility with diverse operational requirements. Each module integrates advanced RF technology to maintain signal integrity over distance, crucial for remote monitoring and control systems. The design emphasizes ease of integration, allowing users to quickly deploy wireless data links without extensive configuration. Key features encompass low power consumption and a compact form factor, making them suitable for embedded systems and portable devices.

Station QRP presents various **circuit diagrams** for constructing low-power AM vacuum tube shortwave transmitters, catering to enthusiasts interested in vintage radio technology. The resource details schematics ranging from simple to more complex designs, enabling hams to build their own QRP AM transmitters for operation on frequencies like 6.925 kHz AM. It emphasizes the use of vacuum tubes, providing a technical foundation for understanding and replicating classic shortwave broadcasting methods. The content is geared towards those who enjoy the hands-on aspect of electronics and the unique characteristics of tube-based RF circuits. Building these transmitters allows operators to experience the nostalgia of early shortwave radio, with the site specifically mentioning a pioneer station on 6.925 kHz AM. The designs facilitate experimentation with low-power AM transmission, offering practical application for homebrew projects. The focus on QRP (low power) operation aligns with a segment of the amateur radio community that values efficiency and minimalist setups, providing a distinct alternative to modern solid-state transceivers.

Low-frequency (LF) radio time signals, operating primarily in the 40–80 kHz range, are broadcast by national physics laboratories for precise clock synchronization. Transmitters like **JJY** (40 kHz, 50 kW; 60 kHz, 50 kW), RTZ (50 kHz, 10 kW ERP), MSF (60 kHz, 15 kW ERP), WWVB (60 kHz, 50 kW ERP), RBU (66.66 kHz, 10 kW), and DCF77 (77.5 kHz, 50 kW) cover vast geographic areas, often several hundred to thousands of kilometers. LF signals offer distinct propagation advantages over higher-band transmissions such as GPS. Their long wavelengths (3–6 km) enable effective diffraction around obstacles like mountains and buildings. The ionosphere and ground act as a waveguide, eliminating the need for line-of-sight and allowing a single powerful station to cover extensive regions. Ground wave propagation minimizes ionospheric variability effects on transmission delay, and signals penetrate most building walls effectively. Robust and low-cost receivers, often priced at 20–30 USD/EUR, are widely used in radio clocks. These receivers typically comprise a tuned ferrite core antenna, a receiver IC (e.g., Atmel T4227, U4223B, MAS1016) for amplification and AM detection, and a microcontroller for decoding the time signal and phase-locking a local clock. Specific components for DCF77, MSF, and WWVB are readily available from vendors like HKW Elektronik and Ultralink.

Patents of most popular antenna models including Zeppelin Antenna, Beverage Antenna , Franklin Antenna , Yagi-Uda Antenna , Sterba Antenna , Rhombic Antenna , Turnstile Antenna , Folded Dipole Antenna , Coaxial Antenna , Slot Antenna , Discone Antenna , Quad Antenna Element , Log Periodic Antenna , Swiss Quad Antenna

Smith Chart it is a graphic tool for solving transmission lines problems