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Query: low band
Links: 634 | Categories: 4
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Presents _Beam Quest_, the official Japanese distributor for _SteppIR_ antennas, detailing their product lineup and services. The site showcases various _SteppIR_ Yagi models, including the _Dream Beam_ series (DB42, DB36, DB18E, DB11) with configurations from two to four elements, alongside the _Big IR_ and _Small IR_ vertical antennas. It also lists accessories such as TX/RX and PC interfaces, essential for integrating these advanced antenna systems into a ham shack. Operators often seek out _SteppIR_ antennas for their dynamically adjustable element lengths, which allow for optimization across multiple bands, a significant advantage for DXing and contesting. This adaptability contrasts sharply with fixed-element Yagis, providing a distinct edge in varying band conditions. The resource provides contact information, including email and phone numbers, for inquiries and support regarding _SteppIR_ products within Japan, serving as a direct point of contact for sales and technical assistance.
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Constructing an End-Fed Half-Wave (EFHW) antenna offers a practical solution for HF operators seeking a multiband wire antenna without the need for extensive radial systems. This design typically employs a high-impedance transformer at the feed point, matching the antenna's inherent high impedance to a 50-ohm coaxial feedline. The article specifically details a 2012 approach, focusing on a transformer with a 49:1 turns ratio, which is a common configuration for EFHW antennas. The resource outlines the construction of a wire element cut for a half-wavelength on the lowest desired band, with specific coil arrangements enabling operation on harmonically related bands such as 40m, 20m, and 10m. It discusses the physical dimensions and winding details for the matching transformer, often utilizing a ferrite toroid core to achieve the necessary impedance transformation. The content provides insights into the operational principles and practical considerations for deploying such an antenna, including methods for tuning and optimizing performance across multiple amateur radio bands. While acknowledging that the presented information from 2012 may be superseded by newer insights, it serves as a foundational reference for understanding EFHW antenna theory and construction.
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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.
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AmTOR may be considered as the next development from RTTY. AmTOR was introduced to overcome the problems with RTTY. As a result of its performance, it has become popular on the HF bands because it gives more reliable communication, especially when interference is present. It achieves this by using a coding system that allows errors to be detected and corrected.
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Aurora, version 0.11.202, offers a comprehensive digital mode station experience, supporting seven distinct modes including FT8, FT4, JT65, JT9, JT4, Q65, and MSK144. The software incorporates its own decoding and transmission engine, eliminating the need for external programs like WSJT-X, and provides a live WebGPU/WebGL2 waterfall display with draggable Rx and Tx bars. Operators can leverage CAT control for more than 300 radio models through Hamlib and OmniRig, enabling frequency, mode, split, PTT, and a radio display with meters and SWR. For DXpedition operations, Aurora includes integrated Fox and UltraFOX modes, managing hound queues and automating QSO logging. The application also features automatic DXCC card tracking, displaying new countries, bands, or modes at a glance based on the operator's log. It supports dual-screen setups, allowing panels, the DX map, or the radio display to be moved to a second monitor, and offers remote control capabilities via a paired phone. Recent updates in version 0.11.202 introduce a beta contest page with 17 rule sets, enhanced automation features like hourly QSO limits and excluded countries, and TCI support for SDRs such as SunSDR/ExpertSDR and ANAN.
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DXLook is a free, web-based propagation platform that delivers comprehensive, real-time insight into HF and VHF conditions directly from any modern browser. It aggregates live spots from PSK Reporter, WSPRnet, RBN, and DX Cluster, complemented by NOAA space-weather metrics such as SFI, K/A indices, and geomagnetic alerts. Integrated VOACAP predictions allow practical "theory versus reality" comparisons, while the interactive world map with filters, gray line, and grid overlays enhances situational awareness. With no installation or maintenance required, DXLook provides a convenient, accurate, and accessible solution for everyday operating and propagation analysis.
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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.
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This page provides a list of UK scanner frequencies, specifically focusing on the Police UHF bands. It is a useful resource for hams interested in monitoring and listening to police communications in the UK. The page offers a detailed breakdown of frequencies used by the police, allowing hams to stay informed and connected to emergency services in their area.
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Presents RigOne, a radio controller application designed for Windows 10 (later releases) and Windows 11, with a macOS version under active development. The software provides core operational controls such as tuning, VFO following, signal metering, and audio management, emphasizing a clean interface for everyday use. It supports native Icom direct control, with the **IC-7300** serving as the primary tested profile, and integrates **Hamlib** for broader compatibility across various transceivers. The resource details specific features, including frequency and mode read/write, VFO A/B switching, quick mode/band selectors, and switchable analog-style or horizontal-bar signal meters. For the IC-7300, RigOne offers an integrated panadapter, waterfall display, native VOX control, and Twin PBT controls, leveraging live scope data for an enhanced visual operating experience. The application focuses on essential functions, avoiding unnecessary clutter. It outlines the latest version, v1.2.5.1, highlighting updates like a compact layout selector for Tall mode, direct frequency entry, and refined fixed 16:9 panel layouts. The page also clarifies hardware compatibility, noting extensive testing with the IC-7300 via USB/COM CI-V, and invites user feedback for expanding Hamlib support to other radio models, ensuring the software evolves based on real-world amateur radio station use.
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This article is about two excellent small helical antennas for the two meters band. With performance close to that of full sized antennas, these small helical antennas are low in profile but high in efficiency.
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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.
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_AT Auto_ is an automatic antenna tuner designed for amateur radio enthusiasts seeking efficient and reliable tuning solutions. This device automates the tuning process, allowing operators to focus on communication rather than manual adjustments. The tuner is compatible with a range of transceivers, enhancing its versatility in different shack setups. Its design incorporates advanced circuitry to ensure optimal performance across various bands. The _AT Auto_ tuner is particularly useful for those operating in HF bands, providing seamless transitions between frequencies. Its integration capabilities with other shack automation products make it a valuable component for modern amateur radio stations. The tuner supports multiple modes, including _SSB_ and _CW_, catering to diverse operating preferences. Its robust construction and user-friendly interface contribute to its appeal among both seasoned operators and those new to the hobby. Kessler Engineering's focus on innovation and quality is evident in the _AT Auto_'s design. The tuner is part of a broader product line that includes shack automation solutions, reflecting the company's commitment to enhancing amateur radio operations. Despite the website redesign, the tuner remains a key offering in their product portfolio.
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AN-SOF is a professional comprehensive software tool for the modeling and simulation of antenna systems. AS-SOF allows to describe antenna geometry, Choose construction materials, Describe the environment and ground conditions, Describe the antenna height above ground, Analize radiation pattern and front-to-back ratio, Plot directivity and gain, Analize input impedance and VSWR,Predict antenna bandwidth
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The Tri-pole antenna, a clever modification of a standard dipole, allows for dual-band operation by integrating a third element. This design effectively shortens the overall dipole length by 10 to 20 percent, simplifying antenna rotation and offering a compact footprint. KK4OBI's article delves into the operational principles, using a 6 and 10-meter Tri-pole as a primary example, and provides comprehensive instructions for constructing any Tri-pole antenna within the 6 to 15-meter range. Key to the Tri-pole's performance is its off-center feed, necessitating a common mode choke at the feed point for optimal tuning and reduced noise. The author outlines a methodical approach to determining element dimensions, starting with a vertical element frequency calculated as 0.47 times the sum of the desired upper and lower band frequencies. This calculation, along with K-values derived from trend lines, guides the initial lengths for the horizontal arms, demonstrating how a 10m-6m Tri-pole can achieve a total horizontal length 78% shorter than a conventional 10-meter dipole. Tuning and balancing are critical, with the article detailing adjustments to arm lengths and the vertical element to achieve balanced SWR values, as validated through 4NEC2 simulations. Radiation patterns are analyzed at various elevations, showing gains around 5.7 dBi and favorable take-off angles for DX contacts. Construction details specify aluminum tubing dimensions, U-bolts, and an SO-239 connector, emphasizing the importance of a ferrite-based choke for wideband operation.
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Examines various low-band receiving antennas, including the Beverage, Pennant, Flag, and Quad, specifically for deployment in noisy city environments. The resource provides a semi-scientific analysis of common receiving antenna types, focusing on their performance characteristics and practical considerations for urban settings. It details construction parameters for each antenna, such as the use of 9:1 baluns and 300-500 Ohm terminating resistors, and discusses the necessity of preamplifiers for certain configurations. Specific deployment advice includes avoiding radial fields to minimize noise pickup and methods for temporary wire antenna installations. The document provides antenna dimensions, noting a full-size Quad requires 540 feet of wire. Performance observations highlight a Quad variant used by N0XA (AB0X) that achieved 160M CQ WW records and facilitated over 120 JA contacts without a preamp.
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The ZS1J/B beacon operates on 28.2025 MHz with 5 Watts output to a half-wave, end-fed vertical antenna, initially installed in 1977 as ZS5VHF near Durban. The 10-meter transmitter is a modified 23-channel CB radio, and the identification keyer uses a diode matrix unit with TTL ICs from the same era. After relocation to Plettenberg Bay in 1993, the beacon has been in continuous service, with additional QRP transmitters later installed for other bands. In 1994, a single-transistor, 80-meter, 0.5-watt QRP transmitter with a half-wave dipole was added on 3586 kHz, followed by a 160-meter, 0.5-watt unit on 1817 kHz. A 30-meter, 0.5-watt transmitter was installed in 1996, operating on 10.124 MHz. In 2002, a 40-meter QRRP beacon on 7029 kHz, with an output of 100 microwatts, achieved DX reports up to 1100 km from ZS6UT in Pretoria. Best DX reports for the 80m and 160m beacons came from 9J2BO.
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This guide explores different radio bands that hobbyists use to talk to each other worldwide. It explains how these bands work and what they're used for. From low-frequency to high-frequency bands, each has its own unique features for people who enjoy communicating through radios
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Longwave refers to all frequencies below the lower end of the AM broadcasting band at 540 kHz
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Narrow Band Emergency Messaging Software (NBEMS) is an Open Source software suite that allows amateur radio operators to reliably send and receive data using nearly any computer (Windows, Mac, and Linux) and any analog radio without requiring a dedicated digital infrastructure or specialized modem hardware
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When operating Parks on the Air (POTA) in public spaces, maintaining a low profile can be advantageous, as VA3KOT discovered. This antenna design draws inspiration from several established concepts: Peter Waters G3OJV's _Invisible HF Vertical_, which uses a 13ft vertical wire and ground radials; Greg KJ6ER's _POTA PERformer_ antenna, known for its raised vertical and reduced radial count; and ideas from Jim Heath W6LG and Frank K4FMH regarding telescoping whips on photographer's tripods. The resulting antenna combines a shortened portable design with a raised feedpoint and two raised radial wires, making it suitable for multiple bands. The construction incorporates a 4:1 impedance transformer, similar to a _Rybakov_ antenna, and necessitates an external tuner for optimal performance across the bands. This approach aims to minimize visual impact while still providing effective HF communication capabilities. VA3KOT built and field-tested this antenna, reporting positive results during POTA activations. The article provides practical insights into its design and operational considerations for fellow activators seeking discreet yet efficient portable setups.
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Presents the official results for the _CQ World Wide 160-Meter Contest_, a premier event for Top Band enthusiasts. The resource details final scores for both CW and SSB segments, offering links to comprehensive articles, plaque winner lists, and club score breakdowns. It also includes access to score databases for individual modes and years, along with "Soapbox/QRM Comments" from participants, providing insights into operating conditions and experiences. This archive spans results from 2010 through 2025, with a forward-looking note regarding the 2026 SSB contest date adjustment due to a conflict with the _ARRL DX CW Contest_. The site provides specific links for each year, allowing operators to review detailed outcomes, including top scores, errata, and all-time records, such as the _SX5R_ 2017 SSB performance. The structured presentation facilitates easy navigation through historical contest data.
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Visualizing DXCC award progress often requires manual parsing of Logbook of the World (LoTW) reports, which can be time-consuming and prone to error. This web-based utility streamlines the process by allowing hams to upload their LoTW DXCC Credit Report spreadsheet, providing an interactive dashboard for tracking confirmed entities, bands, and modes. It processes .xlsx, .xls, and .csv files, performing all calculations client-side within the browser for privacy and speed. The tool presents a comprehensive stats overview, detailing total entities, confirmed slots, and overall completion percentage. It includes progress bars for bands from _160m_ through _2m_, and modes such as CW, Phone, and DIG. A sortable DXCC Entity Details Table lists each entity, its confirmed count, and specific missing band/mode slots, with a CSV export option. Further features include a Band/Mode Matrix grid for granular confirmed status per entity, toggles for specific bands like _6m_ and _2m_, and tracking for DXCC Challenge progress across 10 eligible HF/VHF bands. It also highlights nearly complete entities and identifies most-wanted DXCC entities based on the uploaded data.
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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.
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The Buddistick antenna, as demonstrated by KP4MD, effectively handles up to **250 watts** and provides coverage from 40 through 10 meters, with an optional coil extending operation to 80 and 60 meters. KP4MD's video presentation meticulously describes the antenna setup, emphasizing the critical role of the _shunting coil_ for achieving resonance on lower bands like 40 and 80 meters. This practical approach highlights how a compact antenna can deliver solid performance from a constrained location. SWR curve diagrams are included, clearly illustrating the impact of the shunting coil on the antenna's resonating frequency. These visual aids provide concrete evidence of the adjustments needed for optimal operation across different bands, particularly when space is at a premium. KP4MD's insights are particularly valuable for hams operating from apartments or other limited spaces, showcasing real-world results from a balcony installation.
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The project in this article illustrates how to do this in a simple and low cost way so that you can easily access the microwave bands using the existing HF or HF/VHF transceiver as IF.
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Thsi article describes a microcontroller driven semi-automatic antenna tuner capable of handling power levels up to 150 watts. The device is a low pass filter tuner manually tuned by setting the optimized L/C combination by hand and then storing the values into the EEPROM of the mictrocontroller to recall them later (seperately for each band from 80 to 10 meters including WARC bands)
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Mitigating impulse-type noise, a common challenge in the **HF radio spectrum**, often requires specialized processing before the signal reaches the transceiver's receiver stages. The NR-1 addresses this by functioning as an RF interference removal device, specifically a noise blanker, targeting transient noise sources. Its operational range extends from 1.6 MHz to beyond 70 MHz, making it suitable for various amateur radio bands and general shortwave listening applications. Unlike QRM eliminators or X-phasers, the NR-1 does not require a separate noise antenna for its operation, simplifying its integration into existing station setups. The device's design focuses on wideband performance, allowing its use both within and outside the allocated amateur radio frequencies. Documentation detailing its operation is available, providing insights into its technical specifications and deployment. This unit is a hardware product, conceptualized and implemented by SV3ORA.
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The Baofeng UV-5R handheld transceiver, introduced around 2012, operates across the 2-meter (144-148 MHz) and 70-centimeter (420-450 MHz) amateur bands, offering dual-band receive and transmit capabilities. This review provides an early assessment of the radio's form factor, user interface, and general performance, noting its compact size and the inclusion of a **VFO/Memory mode** button for frequency management. The device supports both FM and narrow FM modes, with a reported power output of 4 watts on VHF and 3 watts on UHF, making it suitable for local simplex and repeater operations. Key features discussed include its 128-channel memory capacity, a built-in VOX function, and a **DTMF keypad** for tone dialing and repeater access. The review highlights the radio's ability to scan frequencies and memories, along with a dual-watch function allowing simultaneous monitoring of two frequencies. Battery life is addressed, with the standard 1800 mAh Li-ion pack providing several hours of operation depending on transmit usage. Initial impressions cover the radio's construction and the clarity of its LCD display, which shows both A and B band frequencies.
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The purpose of this construction is to enable the realization of an HF antenna called W3DZZ with minimal equipment and low cost. It allows traffic on the bands 3.5 / 7/14/21 and 28MHz.
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A dual band vertical antenna for 160 and 80 meters band, on a 18m spiderbeam fiberglass pole. This vertical is a good compromise when you want good performance on these two low ham bands and don't have the space to install two seperate antennas.
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Documents the _XT1T_ DXpedition to Burkina Faso, active from February to March 2013. This operation provided DXers worldwide with an opportunity to work a relatively rare entity, with the team focusing on maximizing contacts across various bands and modes. The expedition utilized an online log provided by _IDT_ (Italian DXpedition Team), enabling immediate verification of contacts and facilitating QSL requests. The _IDT_ system allowed participants to check their QSOs shortly after they were made, a crucial feature for contesters and award hunters aiming for DXCC credit. The expedition's success was measured by the total number of unique contacts and countries worked, contributing significantly to the global DX community's pursuit of new entities.
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A HF power amplifier with a push-pull of AFT09MS015N. The (small-signal) gain of the amplifier is around 26 dB in the lower HF band and goes down to about 24 dB on the higher end and still around 21 dB at 50 MHz. Its input matching is relatively good at the lower HF and degrades above 10 MHz.
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The 3Y0K website is the official platform for the Bouvet Island DXpedition scheduled for February 2026. It serves as a comprehensive resource for amateur radio operators, providing essential information about the expedition, including updates on operations, band availability, and communication modes such as FT8 and CW. The site aims to keep the amateur radio community informed about the expedition's progress and activities, encouraging participation and support. Users can find details on how to donate to the expedition and contact information for inquiries, as well as links to social media for real-time updates and community engagement. In addition to operational details, the 3Y0K site offers various resources for those interested in DXpeditions. It highlights the significance of Bouvet Island as a rare DXCC entity and outlines the logistical challenges faced by the team. The website is designed to be user-friendly, featuring a clear layout that allows visitors to navigate easily through the information. Overall, the 3Y0K website is a valuable resource for amateur radio operators looking to engage with the Bouvet Island DXpedition and enhance their understanding of amateur radio operations.
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The Linked Dipole is a multiband antenna designed for 80/60/40/30/20m bands, optimized for the (tr)uSDX low bands configuration. It incorporates a 1:1 Balun to prevent common mode currents, ensuring balanced operation with coaxial cable. The Balun, wound on an FT140-43 core, achieves 37-40dB attenuation. The design includes a 3D-printable housing for compactness and waterproofing, with labeled link insulators for ease of use. Wire lengths were meticulously adjusted for optimal performance with a 7m pole and 3m rope extension, ensuring the antenna's ends are off the ground for improved behavior. The project includes downloadable printables for DIY construction.
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Anatech Electronics manufactures RF filters for communication systems, Military and commercial, as well as RF filters for Wireless applications. Products include, Band pass filters, Duplexers, Low pass, high pass and bandstop filters. Additional products such as RF cable assembly also available.
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Efficient Low Band Counterpoise for Restricted Circumstances Loss Avoidance Opportunities and Techniques for the Low Bands The short and linear FCP was designed to reduce ground losses from inadequate radial systems beneath inverted L and other vertical antennas.
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Operating in a Single Operator Two Radios (SO2R) setup, especially with beverage antennas, often exposes the receiving radio's front-end to significant RF energy from the transmitting radio. This resource details a practical, homebrew receiver protection circuit designed to mitigate this risk. The core of the design involves a non-inductive 2W 22 Ohm carbon composition resistor in series with the RX antenna line, followed by two stacks of four fast-switching diodes (e.g., _1N914_) configured in opposite polarizations. This arrangement effectively clamps the incoming voltage to approximately 2.8 V peak-to-peak, safeguarding sensitive receiver input components. The series resistor plays a crucial role by absorbing excess power, preventing the diodes from exceeding their current ratings and potentially failing open, which would leave the receiver unprotected. The author, _N4KG_, measured up to 50 watts of coupled power between 80M slopers on the same tower, highlighting the necessity of such protection. The design is presented as a cost-effective solution to prevent damage to receiver input transformers, with the author noting successful protection of a receiver even after a resistor showed signs of overheating. This simple circuit can be integrated via a transverter plug, offering a robust defense against high RF input.
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DecoDXLog is a station logbook application for Windows, designed to integrate seamlessly with the _Decodium_ family of software, as well as _WSJT-X_ and JTDX, by receiving QSOs via UDP. It operates around a local SQLite file, providing automatic callbook lookups from QRZ.com XML or HamQTH to complete log entries with name, QTH, and locator data. The software tracks 15 different awards, including DXCC, WAZ, WAS, WPX, IOTA, POTA, and SOTA, calculating progress in real-time and allowing confirmation via LoTW, paper cards, or eQSL. It also features comprehensive statistics, a world map displaying worked locators and cluster spots, and a built-in DX Cluster client that aggregates data from DX Spider/CC Cluster, Reverse Beacon Network, HamAlert, and POTA activations, providing alerts for new DXCC, band, or mode. The application includes a CW keyer/decoder, a contest mode with real-time scoring and Cabrillo export, and robust QSL management for LoTW, QRZ Logbook, eQSL, and Club Log. An optional DecoDXLog Cloud feature enables synchronization of QSOs, station profiles, and settings across multiple devices, ensuring a consistent operating environment. The software is open-source under the GPL-3.0 license, developed by IU8LMC and contributors, and supports lossless ADIF import/export, making it compatible with existing logs. It also integrates with _DecoRotor_ for antenna control, allowing operators to point their antenna directly from the logbook interface.
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High Speed Multimedia (HSMM) radio, as introduced by John Champa, K8OCL, represents a significant advancement in amateur radio's digital capabilities, moving beyond traditional keyboard modes like packet radio. This initiative, driven by ARRL's Technology Task Force, focuses on developing high-speed digital radio networks capable of up to 20 megabits per second. HSMM primarily facilitates digital voice (DV) and digital video (ADV), enabling real-time video transmission from emergency scenes to an EOC without expensive ATV gear, often requiring only a laptop, a PCMCIA card, a digital camera, and a small antenna. The working group's initial efforts concentrate on cultivating microwave skills within the amateur community to build and support portable and fixed high-speed radio-based local networking, or **RLANs**. These networks prove invaluable for RACES and ARES organizations, as well as homeland security and other emergency communications. Field Day exercises and simulated emergency tests (SETs) are encouraged to hone skills in rapid site surveys and deploying broadband HSMM microwave radio networks, with examples like linking Field Day logging stations or antenna test results at the Midwest VHF-UHF Society Picnic 2003. Getting started with HSMM often involves adapting off-the-shelf **IEEE 802.11** (WiFi) equipment to comply with amateur radio regulations, typically operating in the 2.4 GHz ISM bands. While consumer WiFi gear has range limitations under Part 15 rules, proper setup under amateur regulations can extend coverage significantly, with test networks like the Hinternet achieving 5-15 mile ranges at 54 M bit/s using small mast-mounted dish antennas. Careful selection of equipment with external antenna ports, high transmit power, and low receive sensitivity is crucial, along with using low-loss coaxial cable like LMR-400 for optimal performance at these frequencies.
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If You are using a separate receive antennas then you need a good protection circuit to eliminate the possibility of blowing out the receiver front-end while using these auxiliary receive antennas specially on low bands.
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Voldatech, a manufacturer based in China, produces a range of RF feeder cables and site components essential for amateur radio installations and telecommunication infrastructure. Their product line includes various types of coaxial cables, such as **50 Ohm** and 75 Ohm options, along with a comprehensive selection of connectors like N-type, UHF, and BNC. These components are critical for maintaining signal integrity and minimizing loss in antenna systems, whether for a home shack or a remote DXpedition setup. The company's focus on _RF Coax cables_ and connectors directly supports the needs of radio amateurs seeking reliable transmission lines for their transceivers and antennas. Amateurs often compare Voldatech's offerings to established brands, evaluating factors such as impedance matching, shielding effectiveness, and durability under various environmental conditions. The availability of diverse cable types allows operators to select optimal solutions for different frequency bands and power levels, from QRP to high-power amplifier setups. Their products are particularly relevant for those constructing new antenna arrays or upgrading existing feedline systems, aiming to achieve maximum power transfer and reduce standing wave ratio (SWR) for efficient signal propagation.
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DF0WD/DL4YHF's Longwave Overview details amateur radio operations on the 135.7 to 137.8 kHz segment in Germany. The author outlines the "inofficial" European band plan, specifying segments for QRSS, TX tests, beacons, conventional CW, and data modes. Early LF activities at DF0WD began with a 20-watt CW transmitter, later upgraded to a homemade linear transverter capable of 100 watts, driven by an Icom IC706 on 10.137 MHz. The station's antenna system includes a 200-meter wire, approximately 10 meters above ground, supported by football field light-masts. Despite its length, the antenna's efficiency is noted as very low due to the immense wavelength of about 2.2 km. The author's experience highlights the significant challenge of achieving effective radiated power (EIRP) on LF, estimating DF0WD's EIRP at around 80 milliwatts based on field strength measurements from PA0SE. DF0WD/DL4YHF has successfully worked numerous countries on 136 kHz CW, including DL, F, G, GI, GM, GU, GW, HB9, HB0, LX, OE, OH, OK, OM, ON, OZ, PA, and SM. The author also mentions ongoing efforts to log contacts with CT, EI, LA/LG, and to complete a two-way QSO with Italy, demonstrating persistent activity on this challenging band.
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For my SOTA activities, i recently bought a QRP transceiver QRP SW-3B, which is a three-band QRP CW only for 40/30/20 m. So, i needed an antenna that would allow to use these 3 bands in SOTA portable activity. Already having some experience with the EFHW antenna, i decided to build one for 40/30/20m.
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The 20-10 meter fan dipole antenna described here offers broadside East/West coverage, a characteristic I've found particularly useful for working DX across the Atlantic and Pacific from my QTH. This design connects multiple dipoles of varying lengths in parallel at a single feedpoint, enabling operation across 20, 17, 15, 12, and 10 meters without the need for an external antenna tuner or switching. The guide specifies element lengths for each band, constructed using 1/2 inch PVC pipe for the elements and a 2-inch PVC pipe for the 8-inch long feedpoint connector, ensuring a robust build. Key advantages highlighted include its multi-band coverage, simplified installation, cost-effectiveness, and improved efficiency compared to single-band alternatives. The antenna is horizontally polarized when deployed at a height of 50 feet, providing a favorable radiation pattern for long-haul contacts. Materials required are readily available, including PVC pipes, _RG-8X_ feedline, antenna wire, and guying rope, making it an accessible project for most hams. This _fan dipole_ project provides practical considerations for construction and tuning, aiming for optimal SWR performance across the target bands. The detailed instructions, coupled with the specified components, allow for a straightforward build, even for those with limited antenna building experience, yielding a capable HF antenna for the upper bands.
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DXChrono Desktop presents a comprehensive suite of real-time amateur radio data, including NOAA solar indices, HF band conditions, and a worldwide _F5LEN tropo_ overlay for VHF openings. It integrates live spots from Telnet DX Cluster, PSK Reporter, and Reverse Beacon Network, displaying them on a dynamic 3D globe or 2D flat map. Additional features include aurora and MUF layers, QTH display with optional cities and grid/CQ/ITU layers, and dedicated support for SOTA and POTA activations. The software also offers a Watch List for callsign alerts and Sun/Moon Az/El widgets for satellite and EME operations. The application provides extensive contest and logging context through integration with _N1MM Logger+_ UDP, Cloudlog API, QRZ Logbook, and ADIF file support, allowing recent QSOs to be mapped directly. A Special Event mode is available for club stations, enhancing field day operations. DXChrono Desktop runs on Windows, macOS, Linux, and Raspberry Pi 4/5, requiring a 64-bit OS and at least 4 GB RAM for optimal performance, distinguishing it from simpler HamClock-style appliances.
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256 memories enable the _AT-AUTO_ to recall settings across multiple bands, making it efficient for operators who frequently change frequencies. The tuner is compatible with various antennas and amplifiers, such as the Mercury LUX, and integrates seamlessly with radios like the FLEX 6400 using an RS232-USB connection. This integration allows the tuner to follow frequency changes without additional input, enhancing operational efficiency. Despite being out of production, the _AT-AUTO_ remains supported by Kessler Engineering, which offers firmware updates and repair services. The tuner features a cross-needle SWR meter, providing quick visual feedback during tuning. It also includes a QRO keyline circuit to protect amplifiers during tuning. Users appreciate the tuner's ability to track radios via CAT control, avoiding automatic tuning during QSOs, a common issue with other models. The _AT-AUTO_ is praised for its durability and performance, with many users noting its reliability over years of use. Its ability to handle legal limit power and its balanced line output make it a versatile choice for serious operators. Although it lacks some features like multiple coax outputs found in other models, its robust build and continued support make it a valuable tool for HF enthusiasts.
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With this antenna the coverage is 80,40,20,15 and 10 meter band without any antenna tuner and the average SWR is below 1.2 on phone bands. The total antenna lenght is about 23 meters , with one 20.4 meters long segment from the 1:49 transformer to the 110uh coil and about 2.2 meters long segment from the coil to the insulator.
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PRO-LINK specializes in the manufacturing and distribution of high-quality cabling solutions, including a wide array of fiber optic cables and various coaxial cable types. Their product line encompasses 50-ohm and 75-ohm coaxial cables, essential for diverse RF applications, alongside specialized RF cables and 10Base-T networking cables. The company also provides a selection of connectors and custom cable harnesses, catering to specific installation requirements. Since 1988, PRO-LINK has offered a 5-year warranty on its products, underscoring a commitment to durability and performance. The product catalog details specifications for different cable constructions, such as _RG-58_, _RG-213_, and _LMR-400_ equivalents, which are commonly used in amateur radio installations for antenna feedlines and inter-component connections. Their offerings support both commercial and amateur radio operators seeking reliable signal transmission. The company's focus on robust cable and connector solutions addresses the critical need for low-loss transmission lines in radio communication systems, ensuring signal integrity across various frequency bands.
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Presents various amateur radio topics through blog posts, detailing operational experiences and technical insights from the perspective of SV2YC. The content frequently discusses antenna projects, such as a **portable 20m/40m dipole** designed for rapid deployment, and explores the performance characteristics of different wire configurations in varied field conditions. Observations on propagation and band activity across the HF spectrum are also regularly documented, providing practical context for fellow operators. Specific entries often include detailed accounts of **DX contacts** and participation in minor contests, outlining station setup, power levels, and antenna choices. The blog also covers modifications to commercial transceivers and homebrew accessory construction, offering practical advice on improving station efficiency and functionality. Further posts delve into software applications for logging and digital modes, sharing configurations and operational tips for maximizing their utility in daily amateur radio activities.
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Documents the _5W0M_ DXpedition to Samoa (IOTA OC-097) conducted by a German team from April 4th to 18th, 2013. The resource provides operational details and insights into activating this Pacific entity. It covers the planning, execution, and on-air activities of the multi-operator team, focusing on maximizing contacts across various HF bands. The expedition successfully logged over **30,000 QSOs**, providing DXCC credit for many operators worldwide. The site serves as a historical record, allowing hams to review the expedition's progress and understand the logistical challenges of operating from a remote island. It highlights the strategic band choices and operating techniques employed to achieve a high QSO rate and reach diverse geographical areas.