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LA6EIA Ole's DX-blog details shortwave listening (SWL) and amateur radio DX operations from Norway, providing insights into propagation conditions and station reception. The blog frequently features specific reception reports, often including details such as frequency, mode, and signal strength, alongside observations of various broadcast and utility stations. It documents the author's personal experiences in chasing DX, offering a practical perspective on radio propagation and equipment performance. The content includes logs of received stations, sometimes accompanied by audio clips or screenshots of waterfall displays, illustrating successful decodes or strong signal captures. This resource presents a chronological record of DX achievements and challenges, reflecting the dynamic nature of radio propagation across different bands and times. The blog distinguishes itself by its focus on real-world SWL and amateur radio DXing from a Nordic QTH, offering a unique regional perspective on global radio phenomena. It serves as a personal journal of radio exploration, highlighting specific callsigns, frequencies, and operational details encountered during DX sessions.

CATSync V1.30 integrates OpenWebRX support, expanding its capability to synchronize a local amateur radio transceiver's CAT control with a broader range of public WebSDR receivers. The software facilitates real-time frequency tracking, allowing the operator to adjust their physical rig's VFO and observe the connected WebSDR instantly follow the tuned frequency. This functionality is crucial for remote listening, signal comparison, and verifying propagation conditions across different geographic locations using a familiar hardware interface. The application supports both the classical WebSDR interface and KiwiSDR platforms, providing a consistent control experience across various online SDR deployments. It bridges the gap between local station operation and the vast network of globally distributed software-defined radios, offering a practical tool for DXers and contesters. CATSync is designed for Windows and Linux environments, with Android compatibility noted, making it accessible to a wide user base seeking to leverage WebSDR resources with their existing station setup.

This website is dedicated to Radio Mobile. Radio Mobile is software by Roger Coudé VE2DBE. The program simulates RF propagation and is for free to the amateur radio community. All you want to know about Radio Mobile can be found here.

Accurate meteorological data is crucial for optimizing antenna performance, predicting propagation, and ensuring safe tower work. This resource provides a curated inventory of weather stations, including models like the _AcuRite Atlas_ with lightning detection and the _Ambient Weather WS-2902_ WiFi Smart Weather Station, which offer real-time data on environmental factors. The product listings detail specific features such as direct-to-Wi-Fi connectivity, rainfall tracking, and temperature insights, enabling informed decision-making for various amateur radio operations. The platform categorizes products by application, featuring weather stations tailored for home and backyard use, as well as more robust systems for farm and agriculture, which can be critical for field day operations or remote station monitoring. It also highlights _Made in USA_ options, emphasizing local manufacturing and support. Beyond weather instruments, the site also presents related surveillance technology, such as the _Waggle solar CCTV camera_, designed for outdoor reliability with an IP65 weatherproof rating. This integration allows for comprehensive monitoring of remote ham radio shacks or antenna sites, combining environmental data with visual oversight.

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.

The RBN S-Meter visualizes real-time HF propagation data from the Reverse Beacon Network (RBN). It processes thousands of automated spots per hour, providing a real-time picture of active RF paths on HF bands. Users can set their vantage point using _Region Mode_ or _Grid Square Mode_. Region Mode allows selection from broad geographic areas like E. North America or Europe, while Grid Square Mode uses a Maidenhead grid square and radius for more precise data. The app displays eight region panels, each with horizontal bars for bands 160m through 6m, indicating signal strength with a color ramp from green to red. A dimmer trail shows peak hold values, and an S-unit readout provides additional detail. The app is a free web application accessible on any device, offering a practical tool for ham radio operators interested in CW, RTTY, and FT8 signals. It features a Progressive Web App installation option for enhanced usability on mobile and desktop platforms. Users can install it on Android, iOS, and Windows devices, providing a native app-like experience. The app replaces the previous Windows standalone executable, incorporating user feedback to improve features like grid square mode and automatic location detection.

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

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.

PSK Reporter,is a powerful tool for monitoring your FT8, JT65 or PSK signals around the world. But, even if you are not transmitting on any of these modes it can still be a great propagation tool for determining which bands are open and to where in the world signals from your area are being heard.

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.

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.

The antenna ground or earth system can be key to its operation whilst also being a key safety feature. This article is about grounding systems for antennas, covering different aspects of grounds made for antenna safety, or expressly for lightning or just to improve antenna performance, being ground an antenna component.

Microwaves101 provides an extensive repository of information covering fundamental principles of microwave design, targeting engineers and radio amateurs interested in the higher frequency spectrum. The site features a detailed _encyclopedia_ of microwave terms and concepts, alongside practical design considerations for various components and systems. It serves as a foundational reference for understanding RF propagation, transmission lines, and active/passive microwave circuits. The resource includes numerous calculators for impedance matching, filter design, and other critical RF parameters, facilitating hands-on project development. Discussions on **10 GHz** equipment and **24 GHz** projects highlight practical amateur radio applications, extending to operations up to 134 GHz. Content spans from basic theory to advanced topics like MMIC design and antenna characteristics, supporting both educational and practical endeavors in microwave technology.

Get the most out of your station with K6TU.NET professional grade propagation prediction, and model your antenna performance over actual terrain using high resolution elevation data

Recent researches seem to support the hypothesis that Sporadic E propagation could be connected to presence of thunderstorms.

Accessing current operational statistics for a DXpedition is crucial for DXers planning their next contact. This Club Log page provides a detailed, real-time overview of the 3Y0J Bouvet Island operation, a highly sought-after DXCC entity. It presents a dynamic dashboard showing total QSOs, unique calls worked, and duplicate contacts, all updated as logs are uploaded from the remote location. Users can observe the expedition's progress and strategize their operating times. The interface features interactive charts and graphs, allowing operators to analyze the _3Y0J_ log data by band and mode, including CW, FT8, and SSB. A breakdown of QSOs by continent provides insight into propagation patterns and where the expedition has focused its efforts. The page also includes a map for checking real-time propagation conditions to Bouvet Island, which is invaluable for optimizing contact attempts. Further details include the first and last QSO times, total operating days, and the impact on users' DXCC totals, such as new bands, modes, or DXCC entities worked. This resource is a vital tool for the DX community, offering transparency and actionable intelligence for chasing one of the rarest entities on the air.

Visualizes real-time amateur radio propagation spots using data from the PSK Reporter MQTT stream, providing immediate situational awareness for radio operators. The platform displays spots from various modes, including CW, WSPR, and JT65, in addition to the dominant FT8 digital protocol. FT8 Live focuses exclusively on live data streams, prioritizing current signal activity over historical archiving, which differentiates it from the official PSK Reporter map. A key feature is its integration with the Summits on the Air (SOTA) API, facilitating SOTA chasing by cross-referencing transmitting callsigns with SOTA alerts; a station is identified as an activator if the spot correlates with a scheduled alert within an eight-hour window. The user interface was developed by Arron (ZL1AN), with core data from Philip Gladstone (N1DQ), and stream delivery managed by Tom Stanton (M0LTE).

Discover the key facts about what radio propagation is, the different types available and how they affect different frequencies.

Article about the essentials of radio signal path loss, its causes and prediction, and its use in radio coverage and wireless survey tools

First released in 1988, _SWLog_ is a comprehensive suite of applications providing logging and remote control for both amateur radio and shortwave, utility, and broadcast listening. It integrates program schedules from sources like _HFCC_, _ILGRadio_, and _EiBi_ for broadcast reception, while also linking with amateur radio logbooks such as _ClubLog_, _eQSL_, _QRZ_, and _LoTW_. The software supports radio control for various transceivers, including _Flex_, Icom, Yaesu, and Kenwood, alongside interfaces like _FLRig_, _OmniRig_, and _HamLib_. Mobile applications for Android and iOS facilitate on-the-go logging and remote control, seamlessly transferring logs without manual ADIF export. _SWLog_ leverages an enterprise-grade relational database (SQL Server) for robust data management and analytics, enabling features like mapping QSOs by band or state. It offers specific integrations for _POTA_ monitoring, displaying active spots with real-time propagation and automatic radio tuning. The application's scalability allows multiple users to log to a centralized database, suitable for Field Day or DXpeditions. The user interface features modern aesthetics with light, dark, and gray themes, the latter optimized for outdoor visibility during activities like _POTA_ or _SOTA_. The Plus Edition, available for an annual fee, expands capabilities with advanced QSL integration, additional map providers, and enhanced propagation calculations using _VOACAP_.

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.

Over 500 downloads indicate _aLog365_ is a widely adopted mobile logbook for amateur radio operators, specifically designed for portable operations. It facilitates callsign lookup, real-time QSO uploads to _HRDLOG.net_ / _Ham365_, and offers CAT control via Bluetooth for radio integration. The application supports various export formats, including ADIF, EDI, CSV, and Cabrillo, ensuring compatibility with other logging software and contest submissions. Key features include an integrated DX Cluster and a DXpedition plan, providing operators with current propagation information and upcoming rare entity activations. A unique Instant QSL (iQSL) viewing capability allows for immediate confirmation of successful radio contacts. The app also supports SOTA, POTA, and WWFF operations, making it a versatile tool for activators and hunters alike. Developed by IW1QLH, the application is regularly updated, with the latest version improving performance and stability, and adding Spanish, French, and German language support.

DXFile is a Windows shareware application designed for amateur radio operators, providing comprehensive log management capabilities. The software, developed in Pascal, facilitates real-time and deferred QSO entry, automatically populating fields like frequency, mode, and DXCC country based on user input and system time. It includes features for searching, modifying, and deleting QSO records, with options to sort logs by date, callsign, or entry order. The program offers various printing functions, including QSL card labels in multiple formats, and can generate standard logbook printouts. Beyond basic logging, DXFile integrates modules for tracking progress towards major operating awards such as DXCC, _IOTA_, WAZ, WAS, DDFM, and DIFM. It provides detailed summaries of contacts by band and mode, including graphical representations of HF traffic. A dedicated QSL Manager module assists in processing received QSLs, allowing users to mark confirmations and print multi-line QSL labels. The application also incorporates a DXCC list viewer, which can be updated to ensure accurate country and zone data for logging and award tracking. A distinctive feature is its HF propagation prediction module, which calculates optimal frequencies and signal levels for paths between **250 km** and **6000 km**, considering both E and F layer ionospheric conditions. This module helps operators determine the best times for long-distance contacts. Additionally, DXFile includes a _Web-Cluster_ interface, enabling connection to various DX cluster servers like DXLITE, DXSCAPE, and NC7J for real-time spot information.

This blog chronicles the development of an 80-meter vertical antenna for amateur radio operation. The author constructs a top-loaded vertical using fiberglass poles, achieving significant performance improvements over their previous end-fed wire antenna. Comparative testing using the Reverse Beacon Network and on-air contacts demonstrates 8-10 dB gain on the east coast. The project evolved to include 40-meter capability through a modified design featuring a four-wire vertical cage, loading coil, and strategic guying system. Despite challenges with signal wobble during windy conditions, the vertical consistently outperforms the end-fed wire, particularly for reaching distant stations during nighttime propagation.

Over 15 amateur radio bands, from 160m to 70cm, are supported by the _DXTRON_ web cluster, providing real-time DX spotting information. This service integrates directly with the _QRZCQ_ API, allowing users to monitor activity across various modes including CW, Phone, Digi, RTTY, SSTV, and SAT. DXTRON displays critical spot data such as timestamp, spotter callsign, frequency, mode, DX call, and remarks, along with geographical details like Grid, DXCC, ITU, CQ zone, continent, and country. Developed by _DO5SSB_, DXTRON v1.42 offers a user-friendly interface for filtering spots by band and mode, catering to both casual DXers and serious contesters. The platform is designed for accessibility, providing a clear overview of current propagation conditions and active stations worldwide. This web cluster is a practical tool for hams seeking to identify rare DX, track contest activity, or simply observe band conditions. Its reliance on the QRZCQ API ensures a consistent flow of up-to-date spotting data, making it a reliable resource for real-time operational awareness.

Spotty leverages Philip Gladstone’s pskreporter.info data, delivered via an MQTT broker by Tom Fanning (M0LTE), to offer a responsive web application for visualizing propagation. The Map View presents a default visualization (grid AA00 / callsign MY8CALL) and distinguishes signal types: small spots for signals heard by a location, large spots for transmissions from a location, and teardrop markers for transmissions from the monitored callsign. Clicking a spot reveals detailed signal data in an overlay. The application includes a Log View for raw spot data and a Settings tab for customization. Users can filter tracking by specific Callsign or Grid, with preferences saved to the browser. A notable feature is the Time to Live (TTL) setting, adjustable from the default 60 seconds, which controls spot visibility duration to manage map clutter during high-traffic periods. The tool provides a clear, logic-driven interface for real-time signal monitoring.

The Score Distributor facilitates real-time score forwarding for amateur radio contests, automatically transmitting data from various logging software to multiple online scoreboards. By configuring logging applications to send score data to the Distributor, operators ensure their current score is simultaneously represented on platforms like the _Contest Online ScoreBoard_ (COSB) and the Live Contest Score Server by R4WW. This system eliminates the need to choose a single scoreboard, providing broader visibility for participants. This utility enhances the competitive experience by allowing contesters to monitor their performance against other stations throughout an event. Observing real-time standings can provide significant motivation, particularly during periods of challenging propagation or when striving to maintain pace with club members or peers. The platform supports almost all major contest logging software, simplifying integration for a wide range of operators. Developed by WA7BNM, the Score Distributor was last revised on June 14, 2023. It aggregates score data, offering a unified point of submission that then disseminates the information, ensuring a **single point of entry** for broad scoreboard coverage and improving the dynamic feedback loop for participants.

Demonstrates the _Widget DX HB9HBY_ software, a compact desktop application for amateur radio operators, providing essential real-time information. The widget displays UTC time, current HF propagation conditions, local weather, and thunderstorm risk. It also integrates radio-related links and offers advanced PRO functions, such as a DX map, HF noise radar, IBP beacon synchronization, contest heatmap, aurora radar, and a rare DX radar. The software is available for Windows 10/11 and Linux, with a macOS version planned for future release, and supports both French and English interfaces. Author HB9HBY highlights the widget's simple installation process and automatic update capabilities, which can be silent for minor fixes or include notifications for significant changes. The free version provides core functionalities, while a 15-day free trial unlocks the PRO features. A lifetime PRO license is available for a one-time payment of CHF 10, activating advanced tools that help operators make quicker decisions at the station by correlating propagation, UTC, DX activity, and local conditions, though results remain indicative and require confirmation via listening or tools like _RBN_ or _PSKReporter_.

DecoAlert 1.0 Beta is a companion application designed to enhance the digital mode operating experience, specifically for FT8, FT4, and FT2. It operates by monitoring UDP data streams from primary decoding software like _Decodium_ and _WSJT-X_ on port 2237. The software provides real-time, priority-based audio alerts using WAV sounds for various conditions, including All Time New Ones (ATNO), new DXCC entities per band/mode, user-defined watchlist callsigns, new Maidenhead grid squares, and LoTW-active stations. It also highlights previously worked stations (B4) and integrates live DX spots from Telnet clusters, offering a comprehensive suite of tools for serious digital mode operators. The application features a built-in SQLite database for tracking worked stations and integrates with LoTW user lists to identify confirmed contacts. A DX Cluster client supports multiple Telnet servers, providing a broad view of propagation. PSKReporter statistics are available by band and mode, offering insights into signal paths. The QSO log viewer includes search and filter capabilities, while an _OpenStreetMap_ (OSM) interface visualizes spot locations, aiding in situational awareness. DecoAlert requires Windows 10/11 (64-bit) and compatible digital mode software configured to send UDP data.

Online interactive elevationmap can help radio amateurs by predicting signal propagation, optimizing antenna placement, planning coverage, ensuring line-of-sight, mitigating interference, and enhancing emergency communication. T

With increased ES propagation, this lightweight 5-element LFA antenna offers enhanced performance over the Bigwheel antenna's 5dBi gain, delivering approximately 11dBi and forward gain. Designed from G0KSC’s specifications, the 1.8m antenna was adapted for reduced weight using 6mm and 4mm rods instead of heavier tubes. 3D-printed PETG clamps ensure durability and precision, while the first tests showed excellent SWR and element coupling. Though built with a temporary Choke BalUn, the results were promising, with a Pawsey Stub BalUn planned next for further optimization.

This article focus on the radiation angle of vertical antennas and the fundamentals of electromagnetic wave propagation. The calculation of antenna length at 145 MHz is followed by an explanation of electromagnetic wave speed and the link between wavelength, frequency, and velocity. Author discusses the 5/8th wave vertical antenna, namely its performance and the influence of radiation angle on signal transmission. Figures and analogies demonstrate how different antenna types produce distinct radiation patterns. This highlights the importance of selecting the right antenna for a certain purpose, such as local traffic or dxing. The article discusses a variety of factors that affect antenna performance, including SWR, propagation conditions, and equipment dependability

Analyzes the operational dynamics of the _IARU R1 VHF contest_, the world's largest 2-meter contest, focusing on factors enabling top performers to maintain consistent results amidst declining overall activity. The resource investigates the physical constraints that limit higher point totals, examining how technical capabilities, increased interference, and evolving station setups contribute to contest outcomes. It provides insights into the strategic and technical aspects of achieving high scores, such as the **1,000,000+ point** totals observed from leading stations. Compares the performance of various stations over time, highlighting the sustained success of top contenders and speculating on future trends in VHF contesting. The analysis delves into specific operational strategies and equipment choices that differentiate high-scoring stations, offering a detailed look at the competitive landscape. It also considers the impact of propagation conditions and operator skill on final scores, providing a comprehensive overview of the contest's intricate mechanics and the pursuit of maximum QSO points.

Operating on the HF and VHF bands, the URE WebCluster serves as a real-time DX spotting network for amateur radio operators. It aggregates DX spots from various sources, presenting them with detailed information such as DX callsign, frequency, mode, and spotter details. The platform integrates essential propagation data, including current solar indices like _K-index_ and _A-index_, alongside visual propagation maps, which are crucial for planning long-distance contacts. Users can submit new DX spots, contributing to the collective intelligence of the amateur radio community, and filter existing spots by band, mode, or callsign, enhancing operational efficiency. This resource enables operators to monitor band openings and identify active DX stations, significantly aiding in _DXCC_ pursuit and contest operations. The integration of solar-terrestrial data directly within the cluster interface allows for immediate correlation between propagation conditions and observed DX activity, a feature not universally present in all web clusters. By providing both raw spot data and contextual propagation information, the URE WebCluster offers a practical tool for real-time decision-making during operating sessions, allowing hams to quickly adapt to changing band conditions and target specific _DX_ entities.

The Big Gun's Guide" is a comprehensive exploration of low-band propagation, aimed at serious Amateur Radio operators. It delves into the complex physics of the ionosphere at lower frequencies, contrasting it with HF propagation. The book covers essential topics like ionospheric fundamentals, propagation mechanisms, magneto-ionic effects, and disturbances. It also addresses the challenges of low-band DXing and provides insights for overcoming them. Brown's work is detailed and technical, offering valuable knowledge for those seeking to master the intricacies of low-band communication

The document provides fundamental information on radio wave propagation and NVIS communication, covering line of sight, surface waves, and ionospheric reflection.<p> It focuses on the Near Vertical Incidence Skywave (NVIS) method for reliable coverage in mountainous or skip zones, especially for regional and emergency communications.

Radio wave propagation describes how radio waves travel from one point to another, classified as ground waves, skywaves, and free space propagation. Ground waves propagate over the earth's surface in low/medium frequencies, bending around obstacles but limited to short ranges. They enable AM/FM broadcasting and military submarine communication.

Operating a web-based DX cluster, this resource presents real-time amateur radio DX spots, facilitating contact logging and propagation analysis. It leverages the Spiderweb platform, offering users the ability to filter DX spots based on various criteria, including inclusion and exclusion rules. The interface integrates directly with QRZ.com for immediate callsign lookups, displaying flag icons for geographical context, and provides charts and statistics derived from spot data. Further enhancing its utility for DXers and contesters, the cluster includes direct links to MUF (Maximum Usable Frequency) maps and HamQSL solar condition reports. These external data sources provide critical propagation insights, assisting operators in making informed decisions about band selection and operating times. The service also offers Telnet access at dxc.sv5fri.eu:7300 for those preferring a command-line interface.

Operating amateur radio satellites presents unique challenges, particularly concerning antenna design and signal propagation. Juan Antonio Fernández Montaña, EA4CYQ, recounts his three-year journey into satellite communication, starting with initial guidance from EB4DKA. His early experiments involved a portable 1/4 wave VHF antenna with four 1/4 wave ground planes, designed for hand-held use to adjust polarity. This setup, paired with an FT-3000M transceiver, allowed full-duplex operation on **VHF** transmit and **UHF** receive, proving effective for early contacts on satellites like AO27, UO14, and SO35. EA4CYQ's experience highlights the critical role of coaxial cable loss and antenna polarization. After encountering significant signal degradation with longer RG213 runs, he experimented with a 1/2 inch commercial cable, noting improved reception but persistent fading due to varying satellite polarities. This led to the construction of an **Eggbeater II** antenna, an omnidirectional UHF design offering horizontal polarization at the horizon and circular right polarization at higher elevation angles. Subsequent modifications resulted in the directional **TPM2** antenna, which provided sufficient gain for LEO satellites with a wide 30-degree lobe, enabling consistent contacts from his home station. The article concludes with practical insights on the performance of the Eggbeater II for both UHF and VHF, and the TPM2 for UHF, emphasizing their utility for portable and fixed operations. EA4CYQ's journey underscores the iterative process of antenna development and the importance of adapting designs to overcome real-world propagation challenges in satellite communications.

The Olivia digital mode, a **Multi-Frequency Shift Keying (MFSK)** radioteletype protocol, is specifically engineered for robust communication under difficult propagation conditions on shortwave radio bands from 3 MHz to 30 MHz. Developed by Pawel Jalocha in 2003, Olivia signals can be decoded even when the noise amplitude exceeds the digital signal by over ten times, making it highly effective for transmitting ASCII characters across noisy channels with significant fading and propagation phasing. Early on-the-air tests by Fred OH/DK4ZC and Les VK2DSG on the Europe-Australia 20-meter path demonstrated intercontinental contacts with as little as one-watt RF power under favorable conditions. Common Olivia modes are designated as X/Y, where X represents the number of tones and Y is the bandwidth in Hertz, with examples including 8/250, 16/500, and 32/1000. The resource clarifies that Olivia, unlike some other digital modes, produces a constant envelope, allowing RF power amplifiers to achieve greater conversion efficiencies and making it less prone to non-linearity. Operators are advised that **Automatic Level Control (ALC)** can be set higher than no meter movement for MFSK modulation, as long as it's not driven past its high limit, contrary to common misinformation about other digital modes. The Olivia community encourages voluntary channelization on suggested calling frequencies, such as 14.0725 MHz for 8/250, to facilitate initial contacts, especially for signals below the noise floor. The Olivia Digital DXers Club provides links to Groups.io, Facebook, and Discord for community engagement and offers details on QSO parties.

DXContest.org provides a real-time DX cluster, integrating advanced spotting capabilities with features like _propagation maps_, _PSKReporter_, and the _Reverse Beacon Network_. This platform enables radio amateurs to monitor DX activity, apply sophisticated filters to spot data, and even utilize CAT control for their transceivers directly through the web interface. The service is designed for immediate utility, offering free access without requiring user registration. Users can send DX spots, control their radio via CAT, and consult a contest calendar. The platform also provides traditional Telnet access for those preferring client-based cluster interaction. Developed by Pascual R. Salas Vidal, EA5WU, the service aims to be a comprehensive tool for real-time DX operations and contest participation, offering a blend of modern web features and classic cluster functionality.

Swan provides a real-time, browser-based visualization of **meteor radiants** and forward scatter corridors, serving as a modern re-imagining of the classic Virgo meteor sky visualization tool. It displays meteor radiant and radio scatter geometry, offering both visual and numerical skyview data. The tool updates in real-time, showing current sky conditions and allowing users to pause and review specific timeframes for analysis of meteor shower activity and potential radio propagation paths. This enables operators to identify optimal windows for **meteor scatter** contacts. Operators can utilize Swan to predict and optimize their meteor scatter DX attempts by understanding the geometry between their station, meteor radiants, and potential receive stations. The interface presents critical data points for assessing forward scatter opportunities, which is crucial for maximizing short-duration meteor burst communications. By observing the real-time skyview, users can correlate meteor activity with observed signal enhancements, refining their operating strategies for specific meteor showers or random meteor pings.

The W6PQL 23cm Beacon Project describes a **1296 MHz** beacon designed for microwave propagation studies and equipment testing, capable of 30 watts output. It utilizes a PIC 16F628A microcontroller to generate CW and FSK keying for a crystal oscillator, followed by a series of frequency doublers and triplers to reach the target frequency. The final power amplification stage employs a Mitsubishi M57762 module, providing a robust 10-watt RF output. The design emphasizes stability and reliability for continuous operation, with the microcontroller code, written in assembly, provided for customization of the beacon's callsign and message. Originally located in CM97am and aimed at 140 true, the beacon used four 4-foot Yagis stacked vertically for a total ERP of 3kW. The article includes schematics, parts lists, and construction notes to guide builders, along with antenna pattern measurements. Although the beacon itself is no longer in service as of August 2010, the detailed documentation remains a valuable reference for amateur radio operators interested in building similar **microwave** projects or understanding beacon operation.

Demonstrates the operational status and reach of the LoRa APRS infrastructure, providing a live mapping and logging service for network participants. Users can verify network coverage, monitor _iGates_, and track mobile stations, observing messages and real-time network activity. The platform offers insights into station locations and data flow within the LoRa APRS system, which is crucial for understanding the performance of LoRa technology in Automatic Packet Reporting System applications. This utility helps amateur radio operators understand where transmissions are being received and processed by iGates, and how mobile units are moving within the network. The site's analysis tools provide RF performance monitoring and metrics, enabling users to assess network efficiency and identify areas for improvement. For example, operators can see how many packets are received by specific iGates, or track the path of a mobile station over a **100 km** range, offering practical insights into signal propagation and network reliability for _packet radio_ enthusiasts.