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Query: circle
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The page provides a tool to create a customized Ham Radio Az Map on the fly, with various dimensions available. It is a valuable resource for amateur radio operators to visualize and optimize pointing of directional antennas. The content includes maps for different regions, prefix maps, and world maps.
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HamCalc is a free collection of calculators for radio amateurs include Antenna ERP calculations, Attenuators, Audio Filter design, Coil Winding, Decibels, Great Circles map and calculator, HF Filters, HF Traps, Metric conversions OP Amps QRA Locator to Latitude/Longitude, Radio Horizon calculator, Resonance Satellite orbit calculator Timer calculations (555 timer)Zener Diode calculations Download zip By G4VWL
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GCM is a freeware great circle map plotting software for windows, you can choose colours, scale, meridians, fields and or squares from the maidenhead locator system.
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Sardine Can Antenna. is a BiQuad or Bi circle - wire length each side (8 x 1/4 waves ) 31 mm
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Interactive great circles and QRA Locator map
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GRIDX, a BASIC program that calculates grid squares and Great Circle headings and grid.exe, a grid locator calculator
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The antenna is a vertical dipole, around which four parasitic elements are forming a circle.
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A javascript online calculator of bearing and distances by G4VWL
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This program allows both great-circle (polar) and rectangular projections of the world. The great-circle map is centered on any specified latitude and longitude (the "home" location). The rectangular projection is shown with the home longitude in the middle of the screen.
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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.
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Designing and constructing portable wire antennas for HF operations, this resource explores several configurations including the _foldback dipole_ for space-constrained setups and an inductively shortened dual-band dipole for 20m and 40m. It details the calculation of inductance for shortened elements, providing a Visual Basic 6.0 program screenshot that illustrates determining coil parameters like turns and length for a **25.5 uH** inductor. The document emphasizes practical considerations such as adjusting wire lengths for optimal SWR, noting that a dual-band dipole achieved SWR below 2:1 on both 20m and 40m, with careful adjustment bringing it under 1.5:1. Further, the resource describes a half-wave antenna matched with a coaxial stub, a method often referred to as the _Fuchskreis_ in German amateur radio circles, to transform the high feedpoint impedance to 50 Ohms. This monoband solution, for a 20m application, uses a stub length of **2.98m** (0.216 lambda multiplied by coax velocity factor) and a shorted stub of approximately 48cm. The coaxial stub design is highlighted for its resilience to ground proximity, allowing it to be rolled up or laid on the ground with minimal SWR impact, making it highly suitable for portable QRP operations.
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Great Circle Map for Linux, available for Debian, freeware by SM3GSJ
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GCARA is a general interest amateur radio club intended to promote amateur radio, electronics education and fellowship through amateur radio in the Greater Cincinnati Tristate - Indiana, Ohio and Kentucky area. The club service area lies within a circle having a radius of 25 miles from downtown Cincinnati.
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A 2x3-foot laminated world map product is detailed, offering customization for amateur radio operators. Each map features two distinct views: one centered on the operator's specific station location and another precisely centered on its _antipode_. Countries are clearly labeled, complemented by a tabular listing of all countries. The map integrates a standard latitude/longitude grid alongside concentric circles that delineate distance increments radiating outward from the operator's QTH. Personalization includes the operator's name, callsign, and location printed directly on the map. This custom mapping service provides a unique visual aid for DXing and propagation analysis, allowing operators to quickly ascertain beam headings and distances from their station. The dual-view presentation, particularly the antipodal centering, offers a practical reference for understanding long-path propagation and identifying potential DX opportunities. The inclusion of distance circles and personalized station data makes it a tailored tool for daily operating and contest planning, distinct from generic world maps.
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The receiving antenna setup for the top band, made with a 9 elements vertical antenna array, remote controller and remote relais.
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Operating a QRP station in frigid conditions presents unique challenges, particularly concerning power management and equipment reliability. This resource outlines a specific winter portable configuration, focusing on maintaining operational capability when temperatures drop significantly. It details the use of a _Yaesu FT-817ND_ for digital QRP modes, paired with a _Raspberry Pi_ for digital signal processing and logging, demonstrating a practical approach to cold-weather field communications. The article provides insights into selecting appropriate power sources, such as LiFePO4 batteries, and managing their performance in sub-zero environments. It also covers shelter considerations, including tent selection and heating strategies, crucial for operator comfort and equipment protection during extended activations. The author, _OH8STN_, shares firsthand experience from Arctic Circle operations, emphasizing robust gear choices. Further content includes a video walkthrough, illustrating the physical setup of the station, antenna deployment, and the overall operational workflow in a winterized environment. This visual aid complements the written text, offering a comprehensive view of the entire portable station, from the transceiver to the power system and the protective shelter.
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NCC was formed in 1989 to further the efforts of contesters interested in the CQWW and ARRL DX contests. The member area of the club is a 175 mile circle that includes major parts of Ohio and Pennsylvania.
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DX Maps provides a specialized map printing service, focusing on amateur radio applications such as world prefix maps and custom great circle projections. The platform allows radio operators to visualize propagation paths and DX entities relevant to their QTH and operational goals. This service supports the creation of high-quality, large-format maps tailored for shack display or operational planning. The service facilitates the generation of personalized maps, which can include specific callsign locations, beam headings, and other critical amateur radio data points. Users can specify parameters to create maps that aid in understanding global propagation conditions and optimizing antenna aiming for long-distance contacts. The UK-based operation ensures a localized service for European hams, with international shipping options available. DX Maps also offers QSL card printing, complementing its mapping services.
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Grid Calculator allows you to calculate either a grid square locator or the latitude and longitude of a location. Grid Calculator can be used to calculate a Great Circle bearing and distance between two stations in statute miles, nautical miles, and kilometers.
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An inexpensive portable radio that you can travel with. ATS-505 would be a good choice for a first-time purchaser of a shortwave radio.
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The ICOM IC-R72E a neat compact communications receiver. Coverage: LW, MW, SW (0.1- 30.0 MHz continuous) discontinued in 1998
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A complete review of the Ten-Tec RX340 all mode HF receiver
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A detailed review of the Icom IC-R75 30 kHz -6 0 MHz Receiver first introduced in 1999
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Calculate distance, bearing and more between Latitude/Longitude points. This page presents a variety of calculations for latiÂtude/longiÂtude points, with the formulas and code fragments for implementing them.
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An independent review of the Grundig Yacht Boy 360 portable mediumwave receiver
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The page automatically generate a Great Circle Map (GCM) for ham radio operators based on the IP address or by a given QTH locator. The GCM generated, unlike traditional maps of this type, has been rendered in an elliptical shape instead of a circle. This provides an expanded view horizontally thus making it easier to interpret. The map base is colored with each continent colored differently for easier recognition. The color code of the continents is given below the map for easy reference
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The HF Beacon Tracker is an advanced interactive tool designed for DXers and ham radio opoerators in general to monitor active beacons operating below 14 MHz. Built upon a high-fidelity 3D Earth globe, the application provides a spatial perspective on signal paths by integrating real-time environmental data with a comprehensive beacon database curated by Mirek OK1DUB. Beacons are plotted using precise Maidenhead locators and feature a real-time day/night terminator overlay to help operators identify Gray Line propagation opportunities. With a single click, users can calculate the exact distance from their own QTH to any beacon, visualized via an animated Great-Circle Path arc on the globe surface. To enhance its diagnostic capabilities, the tool seamlessly integrates with PSK Reporter, allowing users to right-click CW beacons to instantly fetch current reception reports and signal strength data. The interface is fully optimized with a mobile-responsive design, smooth globe rotation, and togglable Dark/Light themes suitable for any shack environment. Whether you are performing antenna gain tests, conducting ionospheric research, or simply hunting for band openings, the HF Beacon Tracker transforms raw database information into an intuitive, visual diagnostic suite. It serves as an essential asset for any operator looking to master HF band conditions.
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An homebrew HF Magnetic loop made with 2m length of 6mm diameter copper pipe formed into a near circle as the low loss inductor, a short length of coax as a capacitor,a short length of mains cable, again as a fixed tuned capacitor, a tunable 365pF air spaced capacitor, and a small Jackson C804 airspaced variable with a small 3-35pF trimmer in parallel
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This page by Basu (VU2NSB) presents automatically rendered antenna bearings with geodesic paths projected on a rectangular map. ch geodesic great circle path displayed on the map originates from your location that is derived from your Internet IP address. Therefore the Antenna Bearing Geodesic Map generated below should be accurate and relevant to your physical location (QTH). This map is an alternative to the Great circle Map.
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The Smith Chart, named after its inventor Phillip H. Smith, is a graphic tool used to solve transmission line problems in the field of ham radio operations. By using the Smith Chart, ham radio operators can determine the feed point impedance of an antenna, design impedance-matching networks, and optimize power transfer between a source and its load. The chart consists of resistance and reactance circles, providing a visual representation of complex mathematical relationships related to transmission line operations. Understanding and utilizing the Smith Chart is essential for hams looking to enhance the performance of their RF circuitry.
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Live MUF is a DXC (cluster) telnet client which attempts to resolve propagation modes from spots and also attempts to calculate sporadic e possibilities purely based on incoming data from the cluster. It has great circle mapping (GCM) built in to the app for live mapping of spots. Live MUF also can be used as a world wide converse telnet client, ON4KST telnet client and DXC at the same time. Live MUF also has basic logging capabilities in case you need an emergency logger at any time.
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Detailing a Yaesu FT-857 and ATAS-120 installation in a 1997 Toyota Tacoma, the author used Polar Plot to map signal strength. Using a hand truck with a laptop, FT-817, and an Iron Horse antenna, they circled a chalk-outlined 100-foot diameter, revealing potential nulls towards the truck's rear and through the cab, offering insights into antenna performance.
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The ICOM IC-R75, introduced in 1999, operates on 13.6 Volts DC and measures 241 by 94 by 229 mm. Its coverage spans from 30 kHz to 60 MHz, making it a versatile receiver for various bands. The review details available accessories, including optional filters and the **UT-106 DSP module**, which significantly enhances signal processing capabilities. Performance comparisons are drawn against other notable receivers such as the Drake R8B and earlier ICOM models, providing context for its audio quality and overall functionality. User feedback is integrated, offering practical insights into its daily operation and reception characteristics across the spectrum. This analysis offers an in-depth look at the IC-R75's technical capabilities and features, serving as a valuable reference for operators interested in this **legacy receiver**.
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The **Yaesu FRG-100** shortwave receiver, introduced in 1992, operates across a frequency range of 50 kHz to 30 MHz, accommodating AM, LSB, USB, and CW modes, with an optional narrow-band FM capability. Its physical dimensions are 238 x 93 x 243 mm, with a weight of 3 kg, making it suitable for both portable and fixed station deployments. Power options include standard mains voltage or 12VDC, providing operational flexibility for diverse listening environments. The front panel integrates a manual tuning knob, an analogue signal strength meter, and an LCD display that provides critical information such as frequency, operating mode, memory channel, and time. Users can configure various operational parameters, including tuning steps and bandwidth filters, to optimize reception for specific signals. This review highlights the FRG-100's straightforward interface and its utility for shortwave listening enthusiasts. The design emphasizes user-friendly adjustments for settings, which contributes to its appeal among those interested in general coverage reception.
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Assessing the ICOM IC-R9000 communications receiver, this review details its operational parameters and user experience for radio enthusiasts. Introduced in 1985, the IC-R9000 covers a broad frequency spectrum from 0.1 MHz to 1999.8 MHz, making it suitable for a wide array of listening activities from medium wave (MW) to VHF/UHF. Key performance metrics include a dynamic range of **102 dB** with the narrow SSB filter, crucial for discerning weak signals in crowded bands, and its substantial physical dimensions of 424 x 150 x 365 mm and 20 kg weight. The receiver's architecture supports various modes, though it notably lacks synchronous detection, a feature often desired for improved AM reception under fading conditions. It incorporates 1000 memory channels and robust scanning capabilities, facilitating efficient monitoring across its extensive frequency range. This analysis provides insights into the IC-R9000's capabilities and limitations, offering a historical perspective on a significant piece of amateur radio and shortwave listening hardware.
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Examines the AOR AR-7030 communications receiver, detailing its technical specifications and operational characteristics. The resource describes its compact design, CNC machined aluminum cabinet, and a frequency range spanning 0-32 MHz. Key features include a ceramic metal cased 4 kHz AM filter, with typical bandwidths of 2.2 kHz, 4.0 kHz, 5.3 kHz, and 9.5 kHz, alongside 400 memory channels and multi-timer functionality. It emphasizes the receiver's high-quality components and a design philosophy focused on reliable performance without superfluous features, making it a dedicated tool for serious listeners. The review assesses the AR-7030's performance within its price class, particularly for **medium wave** and **shortwave** reception. It provides insights into how the receiver's design choices, such as its robust construction and specific filter options, translate into practical listening experiences. The analysis highlights its suitability for users prioritizing signal clarity and operational stability over extensive, complex features, offering a clear perspective on its utility for dedicated DXers and broadcast listeners.
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Examines the Sangean ATS-505 portable receiver, a unit introduced in March 2000, providing an in-depth analysis of its capabilities. The review details critical specifications such as its 6 Volt DC power requirement, utilizing 4 AA batteries, and its physical dimensions of 128 x 214 x 39 mm, weighing 840 g without power cells. Frequency coverage spans **LW** from 153-279 kHz, **MW** from 520-1710 kHz, **SW** from 1711-29999 kHz, and FM from 87.5-108 MHz, making it a versatile listener for various broadcast types. Key features highlighted include a backlit display for low-light operation, 45 memory presets for quick access to favorite stations, and the inclusion of Single Sideband (SSB) mode, which is crucial for serious shortwave listening and utility monitoring. The review also draws technical comparisons with other Sangean models, specifically the ATS-404 and ATS-909, pointing out differences in band coverage and operational features. This independent assessment offers practical insights into the ATS-505's performance, helping enthusiasts understand its place within the portable receiver market.