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Query: radio wave
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The Regen Shortwave Receiver using Manhattan-style ugly construction techniques.
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The G5RV antenna, a popular multi-band wire antenna, typically employs a center-fed design with a specific length of 300-ohm or 450-ohm open-wire line acting as an impedance transformer, feeding a coaxial cable run to the shack. Its overall length for 80-10 meters is approximately 102 feet (31 meters) for the flat-top section, with a 34-foot (10.36 meter) matching section. The original design by Louis Varney, G5RV, aimed for efficient operation on 14 MHz (20 meters) as a 3-half-wave antenna, with the matching section providing a good match to 50-ohm coax on that band. While the G5RV offers multi-band capability, its performance varies across bands, often requiring an antenna tuner for optimal SWR on bands other than 20 meters. The matching section's length is critical for its impedance transformation properties, influencing the feedpoint impedance presented to the coaxial cable. Variations like the G5RV Junior and ZS6BKW utilize different flat-top and matching section lengths to optimize performance for specific band sets or to achieve a lower SWR without a tuner on certain bands, demonstrating the adaptability of the basic G5RV concept.
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Mizuho Tsushin Co. was a small Japanese manufacturer of QRP radios and kits, shortwave receiver accessories, and AM broadcast band receiver kits and antennas
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Large picture of a 2011 amateur radio map with DXCC country list
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SDR-RADIO.com is a Windows console for SDR receivers and transceivers. Designed for the commercial, amateur radio and short-wave listener communities, the console provides a powerful interface for all SDR users. Many SDR owners have made their radios available over the internet. Just look at the Web Servers page for a list of the radios you can use. You do not need a licence to use this sodftware with RFSPACE, FUNcube Dongles, Soundcard (SoftRock) and low-end SDRs.
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A quarter-wave vertical antenna design for HF operation offers a practical solution for radio amateurs seeking a compact and efficient multi-band radiator. This project details the construction of a 5-band HF vertical, drawing inspiration from established commercial products such as the _DX COMMANDER_ and the MV6. The design emphasizes ease of assembly and disassembly, making it suitable for portable operations or installations with limited space. The article provides insights into various construction methods and offers practical tips for building a robust yet lightweight antenna. It highlights the benefits of a vertical configuration for DX contacts, particularly on the lower HF bands, and discusses real-world performance observations. The antenna is designed to cover multiple HF bands, providing versatility for various operating scenarios. Operators can achieve significant DX results with this type of antenna, often comparable to more complex arrays, especially when deployed with an effective ground system. The project aims to empower hams to build a capable antenna without significant financial outlay.
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Homebrew a 2 meter 1/4 wave vertical antenna for the 146 mHz ham radio band
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Constructing a Lindenblad antenna for 137MHz NOAA satellite reception involves specific design considerations for optimal performance. The resource details the use of 4mm galvanised steel fencing wire, 300-ohm television ribbon cable, and wood/plastic components for the antenna structure. Key dimensions for a 137.58MHz-resonant antenna are provided, derived from the ARRL Satellite Handbook, specifying s, l, w, and d as 42, 926, 893, and 654mm respectively. The antenna is designed for Right Hand Circularly Polarised (RHCP) signals, requiring the four folded dipole elements to be tilted clockwise by 30 degrees. A significant aspect covered is impedance matching between the antenna's 75-ohm impedance and a typical 50-ohm receiver input. A twelfth-wave matching transformer, constructed from 117mm sections of 50-ohm RG-58 and 75-ohm RG-59 coax with a 0.66 velocity factor, is described. The article also addresses coaxial cable and connector selection, recommending 75-ohm Type-N connectors for RG-6 cable in professional setups and F56/F59 connectors for general use, while strongly advising against PL-259/SO-259 connectors for VHF. Strategies for mitigating Radio Frequency Interference (RFI) are discussed, including antenna placement to shield from local TV transmitters and the use of commercial or DIY band-pass filters, such as cavity resonators or helical notch filters, along with ferrite chokes on coaxial cables. Antenna orientation is explored, noting the Lindenblad's 'cone of silence' directly overhead and its maximized sensitivity towards the horizon. An experimental vertical tilt of 90 degrees is presented as a method to improve overhead reception and reduce interference from strong horizontal signals, particularly relevant in high RFI environments like the Siding Spring Observatory site.
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G4URH calculations to design your own antennas, ground plane, half wave antennas, Quad Antennas and 5/8 verticals
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This doubet antenna is a half wave dipole antenna easy to build, in french
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JJ0DRC's HF multi-band delta loop antenna project, initially conceived during the waning peak of Cycle 23, addresses the common challenge of achieving effective DX operation from a small residential lot in Japan. Dissatisfied with a ground plane antenna's performance in SSB pile-ups, the author sought a beam-like solution without a tower, drawing inspiration from a JJ1VKL article in CQ Ham Radio Sep. 2000. The antenna, constructed in October 2000, employs two 7.2-meter fishing rods (37% carbon fiber, reinforced with cyano-acrylate glue and aluminum tape) and 1mm enameled wire, fed by an Icom AH-4 external antenna tuner. While the exact beam pattern remains unmeasured, JJ0DRC observed a significantly higher callback rate compared to dipole antennas, particularly on higher bands. The system's circumference length of 15-20m is crucial for maintaining a good beam pattern across HF bands, though performance on lower bands like 80m, 40m, and 30m becomes less directional as the length deviates from a full wavelength. Ongoing maintenance addressed degradation issues, including aluminum tape cracking and wire breakage at connection points due to strong winds (often exceeding 10-15m/s in winter). The author reinforced rod connections with IRECTOR PIPE SYSTEM components and INSU-ROCK ties, and improved wire attachment methods using Cremona rope and epoxy bond to enhance durability.
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Amateur Radio, Citizen's Band Radio, Commercial Radio, General Electronic items, Marine Radio, and Short Wave Radios, Hamilton Ohio
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Rhombic antenna for shortwave radio broadcasting, general description and radiation patterns
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Supplier of amateur radio equipment for 50MHz and above in New Jersey
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PathSim is a Windows program that can be used to simulate radio propagation paths using a soundcard and/or wave files as the source and destination.
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A short wave regenerative receiver project by Charles Kitchin, N1TEV
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The National Radio Club is the world's oldest and largest Medium Wave DX club, founded in 1933.
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N3FJP's ARRL Field Day Contest Log 6.6.10 is a dedicated software solution for Windows 7 through Windows 11, specifically tailored for the annual ARRL Field Day event in June. This program provides essential contesting features such as duplicate checking, including partials, and a dynamic list of sections that change color upon being worked. It seamlessly interfaces with popular digital mode software like WSJT-X, Fldigi, and JTAlert via API, and supports rig control for most Elecraft, Icom, Kenwood, and Yaesu transceivers. The software also generates computer-generated CW via serial port or Winkeyer, plays wave files, and offers DX spotting capabilities. Operators can leverage its fully networkable design to allow multiple PCs to update a single log file simultaneously, enhancing club operations during Field Day. The program outputs ASCII log, dupe, and summary files for contest submission and provides real-time statistics. A quick start video is available to guide new users through the basics of the software. Registration for permanent use costs $8.99, or it can be obtained as part of the N3FJP Software Package, which includes over one hundred amateur radio programs for a one-time fee of $59.99.
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About numbers stations, and their criptic transmissions, where to listen to them and some audio recording samples by fascinating shortwaves
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Generating Morse code audio files from text input is the primary function of _MorseGen v1.2_, a utility designed for amateur radio operators. The software allows users to specify the tone frequency and words-per-minute (WPM) speed for the generated CW. A key feature is its ability to create a WAVE audio file containing the Morse code, which can then be used in various applications. The program also supports repeating the generated CW sequence at user-defined intervals, making it particularly useful for creating station identification signals or beacons. The practical application of this tool extends to automated station identification, especially for repeaters or digital mode gateways that require a CW ident. By producing a standard _WAVE file_, the output is compatible with most audio playback systems and software. This functionality provides a straightforward method for integrating custom Morse code messages into existing amateur radio setups, eliminating the need for external hardware keyers for simple identification tasks. The adjustable parameters offer flexibility to match specific operational requirements or personal preferences for CW characteristics.
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The Grid Yagi (or Grid Quad) is a high performance yagi antenna that can be built with readily obtainable inexpensive materials. Described here is a 6 element 2 meter version with a boom length of about 1 wavelength, shown
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Understanding high-frequency (HF) skywave propagation is crucial for amateur radio operators seeking to optimize long-distance communications. This resource details the fundamental principles of HF radio propagation, including the properties of electromagnetic waves, the characteristics of various HF bands, and distinct propagation modes such as skywave, ground wave, and line-of-sight. It places significant emphasis on the ionosphere's pivotal role in refracting HF waves, explaining how solar activity directly influences ionospheric conditions and, consequently, propagation paths. The resource integrates real-time monitoring capabilities, featuring dynamic charts and data from DX clusters, WSPRnet, and the Reverse Beacon Network, which allow users to track current band activity and propagation conditions globally. It also delves into advanced topics like Near Vertical Incidence Skywave (NVIS) and gray line propagation, providing insights into ionosonde data and various propagation prediction models. The site presents a detailed analysis of solar-terrestrial interactions, geomagnetic indices, and space weather phenomena, illustrating their direct impact on HF communication reliability. Practical tools and applications are highlighted, including real-time QSO planners, online Maximum Usable Frequency (MUF) maps, and alerts for solar flares or geomagnetic storms. The guide systematically breaks down complex concepts into accessible chapters, offering a structured approach to learning about ionospheric regions, diurnal and seasonal effects, and the interpretation of propagation indicators like foF2, MUF, and Lowest Usable Frequency (LUF). This makes it a robust reference for hams aiming to deepen their technical understanding and improve operational effectiveness.
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Long Waves, Short Antennas, designing antennas for MF and LF communications
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HFCC manages and co-ordinates global databases of international shortwave broadcasting in keeping with International Radio Regulations of the ITU. Operational Schedule, available for free download and iteractive schedule
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Terrasat Communications specializes in advanced RF technology for satellite communication, focusing on _Intelligent Block Up Converters_ (IBUCs) and Solid State Power Amplifiers (SSPAs). These products are engineered to enhance satellite link performance, offering features like extended frequency ranges and high power efficiency. The IBUC series, for instance, integrates a BUC with an SSPA, enabling operators to install, configure, and monitor units for both commercial and military satellite applications, ensuring reliable, high-performance connectivity worldwide. The company's offerings support various satellite bands, including C, X, Ku, and Ka, providing solutions for diverse operational requirements. Their technology is designed for robust field performance, with products like the _IBUC2_ and _IBUCG_ models demonstrating the integration of advanced diagnostics and control capabilities, which are crucial for maintaining optimal signal integrity in demanding environments. Terrasat's focus on _SSPA_ technology underscores a commitment to power efficiency and compact design.
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HFUnderground.com is dedicated to documenting longwave, mediumwave, and shortwave stations, including broadcasters, utility/military stations, pirate radio and spy numbers stations.
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The half wave dipole antenna is a simple and practical antenna model that consists of a half wavelength long centre fed conductor.
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An Active antenna designed for VLF and shortwave radio reception. A small antenna capable of excellent performances on low bands, made on a copper plate and introductio to active antennas.
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Loop antennae have been used from ELF to UHF since the beginning of radiocommunications. At low frequencies, the main problem for loop antennae is to have enough sensitivity; the antenna being very small respect to the wavelength the collected energy is also small. To increase the output level the loop may be made resonant, so loosing it%u2019s intrinsic aperiodic characteristics.
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HD Communications Corp specializes in **RF and microwave amplifiers** engineered for demanding communication, defense, and industrial applications. Their product line includes precision-built, high-power solutions, along with RF connectors, filters, HF cables, and various accessories. The company also supplies tower hardware, valves, and tubes, catering to a broad spectrum of radio frequency infrastructure needs. Beyond amplifiers, HD Communications offers a range of **RF filters**, including low-pass filters, antenna filters, and solutions for RFI/TVI mitigation. Their inventory encompasses essential components like coaxial cable and various connector types, supporting both amateur radio and professional installations. The company operates as a manufacturer and vendor, providing direct sales of its specialized RF products.
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It consists of a radiating wire with a length equal to the half-wave of the fundamental frequency for which the antenna is cut.
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This program displays solar-terrestrial data for radio waves propagation that is provided by the N0NBH web-service.
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The IndyScan website functions as a personal blog, documenting the author's experiences across various aspects of daily life, including travel, culinary adventures, and media consumption. Content frequently details personal trips, dining experiences in Indiana and other locations, and reviews of books, television shows, and products. The site also includes reflections on local events and personal purchases, providing a snapshot of the author's interests and activities. While the site's primary focus is personal narrative, it occasionally touches upon amateur radio, such as mentions of operating during a trip to Brookville, Indiana, or capturing a weather fax via shortwave radio. These ham radio-related entries are integrated within broader lifestyle updates, offering a glimpse into the author's engagement with the hobby rather than providing technical guides or detailed operational information. The resource serves as a personal journal, not a dedicated technical reference for amateur radio.
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Deciphering weak or noisy **CW** (Continuous Wave) signals often presents a challenge for amateur radio operators, particularly in contest environments or during DXpeditions. CWLab04X addresses this by providing a software solution that leverages **DSP** (Digital Signal Processing) capabilities of a soundcard to decode Morse code. It functions as both a receiver and a sender, supporting traditional CW and a unique "CCW" mode designed to enhance copyability of signals struggling against high noise floors. The program offers two installation methods: a Windows-specific installer for straightforward setup or a zipped package compatible with Windows and Linux systems running Wine. Users must first download and review the accompanying PDF documentation, CWLab04.pdf and CWLab04_Hardware.pdf, which detail the software's operation and the necessary soundcard interface circuit. The hardware PDF outlines a direct connection from the receiver audio output to the soundcard input, with optional conversion of the soundcard output for hard-keying or microphone input. CWLab04X is intended as an operational aid rather than a replacement for skilled human copy, particularly highlighting the effectiveness of its CCW mode in adverse signal conditions. The software was last revised in April 2009, with installation requiring the LV Runtime 602.
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Shortwave radio reviews ar swling.com
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AN Wireless is a manufacturer and distributor of Self Supporting Tower Systems for Wireless Communications, Wireless Internet, Wireless Networking, Microwave, Paging, Broadcast, Two-Way Radio and Amateur Radio.
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HF Weather Fax lets you receive marine weather radiofascimile transmissions on your iPad, iPhone and iPod Touch. Just connect it to a shortwave radio tune in a weather fax frequency, and watch the images come in.
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The Voice of America (VOA) website serves as a primary digital platform for its international news and information services, broadcasting in 44 languages. The resource presents a wide array of current events, geopolitical analyses, and cultural reports, reflecting a global perspective on news originating from the United States. Content spans various regions, including Africa, Asia, the Middle East, and specific country-focused reports from VOA's language services, such as VOA Uzbek, VOA Kurdish, and VOA Russian. The site features top stories, special reports, and sections like "All About America" and "VOA Explains," providing in-depth context on US-related topics and global issues. The VOA platform offers a continuous stream of updated news articles, covering political developments like government shutdowns, diplomatic relations, and international conflicts, alongside social and economic issues. It also includes sections for "Worth Watching" videos and "From VOA's Language Services," highlighting the breadth of its multimedia output. The content is designed to inform a worldwide audience, often presenting multiple perspectives on complex international events and US foreign policy, making it a significant reference for those monitoring global news and shortwave broadcast content.
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Generic PI4 + CW + Carrier Arduino Beacon Controller with interfacing to Analog Devices AD9833 DDS AD9850 DDS, AD9851 DDS, AD9912 DDS , AD9913 DDS, ADF4350 and ADF4351 synthesizers, ADF5355 synthesizer, ADF5356 synthesizer, Radio modulated by an audio soft-DDS Reverse DDS, RDDS microwave unit, Silicon Labs Si5351A programmable clock generator, Silicon Labs Si570 programmable XO/VCXO, Texas Instruments LMX2541 synthesizer
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One of the most useful antennas in the repertoire is the Marconi or quarter wave grounded vertical antenna. Its invention made it possible to halve the length of antennas, simplifying communications, especially at HF and below.
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Presents a dynamic, searchable database of shortwave broadcast schedules from around the world, enabling users to locate active stations or plan listening sessions based on scheduled transmission periods and frequencies. The resource details specific station names, such as _Radio Habana Cuba_, _Deutsche Welle_, and _All India Radio_, alongside their operational times and assigned kilohertz frequencies. It also incorporates a distance calculator, which leverages geographical coordinates to estimate propagation paths, though it notes occasional data inaccuracies leading to transmitters appearing in oceanic locations. The platform's development log highlights continuous updates, including the integration of new seasonal schedules like "A24 frequencies" and "B23 schedule," reflecting the fluid nature of shortwave broadcasting. It documents challenges with geolocation services, particularly concerning Google API changes that impacted distance calculations and required user-side browser configuration adjustments for optimal functionality. The site owner, VAXXi, frequently communicates these technical adjustments and database updates, often acknowledging user contributions and donations. Distinctively, the resource provides a historical perspective through its update archives, illustrating the evolution of shortwave listening over more than a decade since its inception in 2011. It also mentions specific events, such as the BBC adding shortwave broadcasts for Ukraine on 5875 kHz and 15735 kHz, demonstrating its responsiveness to global events impacting broadcast schedules. The site's commitment to user feedback is evident in its bug reporting and feature request mechanisms, contributing to its ongoing refinement.
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Excellent slides explaining radio and radiowaves generation basics
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Flash Movie describing HF (shortwave) radio propagation to beginners. Very helpful aid in understanding.
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Shortwave Radio Schedules from Eibi/AOKI combined lists. Includes Google maps showing beam directions and long paths.
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50 MHz meteor scatter offers a unique opportunity for amateur radio operators to make long-distance QSOs, even when the band appears dead. Meteor scatter involves reflecting radio waves off the ionized trails left by meteors burning up in the upper atmosphere, typically around 105 km high. These trails can facilitate contacts over distances up to approximately 2,300 km. The technique is particularly effective during meteor showers, which increase the number of meteors and thus the chances of successful QSOs. However, random meteors can also be used to achieve contacts, especially on the 50 MHz band, where the longer reflection time compared to 144 MHz makes it easier to work meteor scatter. Operators should be prepared to make QSOs in short bursts, often lasting only a few seconds. The IARU Region 1 meteor scatter procedure recommends using 2.5-minute periods for telegraphy and 1-minute periods for SSB, though shorter periods can be arranged. For 50 MHz SSB, 15-second timing is often used to maximize the chances of completing a contact. The procedure involves specific timing for transmissions based on direction and requires both operators to confirm receipt of callsigns and reports to complete a QSO. Understanding the geometry of meteor scatter, including the optimal radiation angles and the concept of 'hot spots,' is crucial. These hot spots are areas where reflections are most likely to occur, influenced by the Earth's rotation and the path of the meteors. Proper antenna setup, including elevation control and beam direction, can significantly enhance the chances of successful meteor scatter QSOs.
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This online article provides a list of individuals who hold or have held amateur radio callsigns, detailing their public recognition. The resource identifies specific callsigns such as **K1JT** (Joe Taylor, Nobel Prize in Physics), **W6OBB** (Art Bell, syndicated radio personality), and **JY1** (King Hussein of Jordan), linking them to their non-amateur achievements. It also notes operational statuses like _Silent Key_ for deceased operators and _lapsed callsign_ for inactive licenses. The article includes information on callsign changes due to vanity callsign programs and provides examples of individuals involved in specific technical areas, such as Percy L. Spencer (**W1GBE**), inventor of the microwave oven, and Jay Kolinsky (**NE2Q**), inventor of electronic sirens. It also references amateur radio involvement in _space missions_ for individuals like Owen Garriot (**W5LFL**) and Helen Sharman (**GB1MIR**). DXZone Focus: Online Article | Famous Hams | Callsign Status | Vanity Callsigns
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Ham radio antennas and electronics, specialized in 1/2 wave dipole, OCF dipole, windom, full wave loop, end fed, inverted L, portable end fed antenna, long wire, SWL antenna, fan dipole, multiband dipole, G5RV and military antennas.