Search results

OpenHamClock is a modern, open-source dashboard for amateur radio operators, designed as a web-based successor to the original HamClock. Deployable locally on a Raspberry Pi or via the cloud, it centralizes essential DX operations into a single, intuitive interface. At its core is an interactive world map that visualizes real-time DX spots, signal paths, satellite tracking, and POTA activators. The software seamlessly integrates critical tools like WSJT-X, DX Cluster, and PSKReporter for monitoring digital traffic. Additionally, it provides vital environmental data, including real-time space weather indices, solar activity, and personalized HF propagation predictions. With customizable themes and a modular architecture, OpenHamClock offers modern operators comprehensive, at-a-glance situational awareness of global radio conditions

Contest station situated in the South West part of the Netherlands in the province of Zeeland

To promote and practice amateur radio and HAM radio in Mumbai, India.

Launch of a hybrid rocket from high altitude by untsville Alabama L5 Society

Appendix 42 to the Radio Regulations, published by the International Telecommunication Union (ITU), serves as the authoritative global reference for assigning call sign series to countries. This essential resource allows radio operators, including those in the amateur service, to accurately identify the national origin of a station based on its callsign prefix. It is fundamental for DXers, contesters, and anyone involved in international two-way radio communication, ensuring correct country identification for awards like _DXCC_. The table details the specific blocks of call signs allocated to each administration, facilitating the unambiguous determination of a station's geographical location. For instance, prefixes like K, W, N, and AA-AL are assigned to the United States, while G and M series denote the United Kingdom. Understanding these allocations is crucial for logging contacts and verifying QSLs. This ITU publication is regularly updated to reflect changes in national assignments and new allocations, maintaining its accuracy as the definitive source for call sign series worldwide. It underpins the global framework of radio communication.

The RACES ARES Disaster Assistance Repeaters (RADAR) group was formed by a team of amateur radio operators dedicated to providing high quality repeater communications for amateurs involved in public service communications or response to emergency/disaster situations.

A dynamic collection of high latitude geomagnetic data from 12 Canadian observatories

Blog post by Adrian M0NWK showing how to calculate the latitude and longitude at the centre of a Maidenhead locator using basic maths.

Real-time solar activity page at SpaceWeatherLive.com display sunspot regions, indicating sunspot numbers of with manitude class, Solar Flares and a list of daily events on the sun.

Amplitude Modulation (AM) is essentially a mixing process where the audio modulating signal is mixed with the radio frequency carrier

Calculate distance, bearing and more between Latitude/Longitude points. This page presents a variety of calculations for lati­tude/longi­tude points, with the formulas and code fragments for implementing them.

GridLocW is a free Lat/Long to Maidenhead converter for Windows - with optional GPS support, includes the formula to calculate geodesic distance (in m) between two points specified by latitude/longitude.

We are a contest station situated in the South West part of the Netherlands in the province of Zeeland,

Storm Cable is part of Teledyne Cable Solutions, an integrated alliance dedicated to supplying the industry with engineered solutions to challenging cable situations.

The Icom IC-7700 spectrum scope feature a minimum resolution bandwidth of just 100 Hz and provide also an accurate vertical amplitude tracking permitting to use the 7700 as a bench spectrum analyser.

NearSys (Near Space Systems) is a multifaceted organization, with interests in near space exploration, microcontrollers, robotics, space, and astronomy. Includes a section dedicsated to Amateur Radio High Altitude Ballooning

An article on amplitude modulation (AM) operation on VHF bands.

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.

You can use this tool to calculate the maidenhead square by entering the longitude and latitude.

This document details the construction of a multi-band end-fed antenna, suitable for situations with limited space for larger antennas. The design utilizes a 1:49 to 1:60 impedance transformer to match a half-wave wire antenna fed at one end. Compared to a traditional dipole, this antenna resembles a highly unbalanced Windom antenna with one very long leg and a virtual short leg. The design eliminates the need for radials but relies on the coax cable shield for grounding. The document recommends using at least 10 meters of coax and installing a common mode filter at the entry point to the shack for improved performance.

A step by step guide to install the NS Roofing filter into the Yaesu FT-2000

Vertical antenna tests at the Sonten-Rancabali tea resort in Ciwidey, West Java. The assembly, led by Mr. Dian Kurniawan and the team, took just 20 minutes. Mrs. Mita performed the transmit check-in test, which was received across various regions in Indonesia, including Sulawesi, East Java, and Bangka Belitung. The team will release a video of the test soon and has thanked colleagues YB3HRY and YB0BAW for their reports.

This utility program shows the impedance and reflection coefficient parameters (SWR, reflection coefficient magnitude Rho, or Return Loss RL in dB) at both ends of a transmission line and the details of power loss in the line. It includes built-in specifications for approximately 100 different line types. You can modify the specs to see how small changes affect the results or to specify custom lines. All program inputs may be changed directly or you can use spin buttons to make the changes.

High Altitude Ballooning makes for a challenging project that sometimes turns into an engrossing hobby. Whilst it is not rocket science it does encompass a wide range of fields (sometimes literally) and there is a lot to learn before you send your first flight up into the sky.

For low voltage applications, like cathode bypass capacitors, most vintage types have an axial configuration, which is less common today but still available. Electrolytic power supply caps likely constitute the single worst liability in old audio, radio and test equipment. Rap about Electrolytics, Reforming, Chassis-Mount Replacements, Under-Chassis Installation, Rebuilding Capacitors

In a quest for reliable emergency power, the article discusses the necessity of accessible power solutions amidst blackouts and energy crises. It introduces the American-made Merlin Panther 100-watt solar briefcase and budget-friendly LiFePO4 batteries. The setup addresses the need for modular, renewable power solutions, balancing cost-effectiveness with functionality for various scenarios. The narrative emphasizes the importance of reliable power sources in unpredictable situations.

IAT is an excel sheet table evaluate parameters of VHF UHF antennas edited by Vladimir UR5EAZ. The difference between this tool and the existing VE7BQH Antenna Table is the use of G / T and C / N instead of the G / Ta parameter. In this table, Vladimir applies the ITU recommendations to assess the noise properties of a radio receiving system and shows the advantage of the G / T concept over the G / Ta concept when choosing an antenna.

FT8 Live is a specialized web-based tool designed for the real-time graphical visualization of amateur radio propagation spots. Leveraging the data infrastructure of the PSK Reporter MQTT stream, the platform provides immediate situational awareness for radio operators. While the tool’s nomenclature references the dominant FT8 digital protocol, it offers broad compatibility, displaying spots from various other modes including CW, WSPR, and JT65. Distinct from the official PSK Reporter map, FT8 Live focuses exclusively on live data streams, eschewing historical archiving to prioritize current signal activity. A defining feature of the platform is its integration with the Summits on the Air (SOTA) API. This functionality facilitates "SOTA chasing" by automatically 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 tool represents a collaborative technical effort, featuring a user interface developed by Arron (ZL1AN), utilizing core data from Philip Gladstone (N1DQ), and stream delivery via Tom Stanton (M0LTE).

Online antenna calculator for a basic 3 elements yagi uda directional antenna. The described antenna design offers a front-to-back ratio of at least 20 dB, a gain exceeding 7.3 dBi, and a bandwidth (SWR < 2) of approximately 7% around the center frequency. It has an input impedance of 50 ohms when using a straight split dipole, which can be substituted with a folded dipole of the same length, increasing the impedance to 200 ohms. A matching balun is required for coaxial feeder connection, and the boom should be made of a dielectric material, like wood.

The article details the design and construction of a four-band Moxon beam by a radio amateur. The beam, mounted atop a rooftop tower, aimed for gain over a dipole on 20 meters, cost under $500, and included additional bands. The design features fiberglass spreaders, four bands (20/15/10/6 meters), and a single feedpoint. The construction involved computer modeling, NEC source code, and specific dimensions. The article outlines the assembly, materials, and tuning process, including in-situ adjustments for optimal performance. Despite initial challenges, the beam improved signal strength and facilitated contacts on multiple bands, marking it as the best HF antenna the author has owned.

Open source code to add CQ Zone, ITU Zone and Maidenhead Locator to your leaflet maps.

Recommendation M.1677-1 (10/2009), General transmission rules, Morse code, signals, spacing and length of the signals.

Hamradio_copilot is an open-source tool designed for DXers and contesters who need real-time situational awareness. It is ideal for operators who want to visualize propagation trends instantly rather than scrolling through raw text streams of cluster spots. Rally acting as a copilot for your station, this tool transforms raw data into actionable intelligence. By visualizing Signal-to-Noise Ratios (SNR) across different bands, it helps operators make quick decisions on which band to prioritize or where to point their antennas, effectively showing not just who is on air, but where the propagation is currently open from your location. This is a fantastic information for avid contesters. The software aggregates data from two primary services: - Reverse Beacon Network (RBN) via Telnet. - PSK Reporter via MQTT feeds. It processes this data to generate a comprehensive HTML report featuring SNR heatmaps and statistical breakdowns by ITU Zone. Users can filter data by specific zones or country codes (ADIF), analyze historic time ranges, and optionally integrate solar weather data. The complete source code is available on GitHub, allowing for community customization. It is written in Python and uses SQLite for data management.

Optimizing a QRZ.com page involves adding essential callsign data, ensuring correct _Maidenhead Gridsquare_ and DXCC information in the Detail tab, and populating the Biography section with relevant station details. Operators should include their operating conditions, specific country references like WAB square, club affiliations, and detailed QSL information, specifying preferences for electronic confirmations (e.g., _LoTW_, Clublog) and paper QSLs (direct, bureau, SASE). The guide emphasizes the importance of accurate data for electronic logging software integration, which fetches Gridsquare, DXCC, and CQ/ITU zones to populate contact logs correctly. Further enhancements include leveraging the QRZ.com photo gallery for images and setting a primary image that logging software like _Log4OM_ can display. Advanced customization involves embedding external services via HTML source code. Examples include integrating HamAlert for DX Cluster spots, Clublog for log searches and Online QSL Requesting (OQRS), and Parks on the Air (POTA) statistics widgets from WD4DAN. Additionally, live weather information from Weather&Radar and solar data banners from HamQSL can be embedded, providing real-time environmental context for visitors to the QRZ page. These embedded tools require creating accounts on respective platforms and often involve copying specific source code snippets into the QRZ biography's HTML editor, ensuring callsign placeholders are updated.

The most basic form of repeater receives communication on one frequency and re-transmits it on a different frequency, a process known as duplex communication. This capability significantly extends the range of handheld and mobile radios, as repeaters are typically situated at elevated locations with high-gain antennas and greater transmit power. Repeaters commonly operate with FM modulation on the VHF (30 MHz – 300 MHz) and UHF (300 MHz – 3 GHz) amateur bands, which are ideal for portable and mobile devices. Access to repeaters is often controlled by a CTCSS or PL tone, an inaudible signal that prevents the repeater from retransmitting background noise. This mechanism ensures efficient use of the frequency and prevents illegal continuous transmission. Canadian regulations, for instance, require an Advanced amateur radio license and an available frequency within the band to set up a repeater, each assigned a unique call sign and transmit frequency. Configuring a radio for repeater use involves knowing the repeater's transmit frequency, its receive frequency offset (e.g., -600 KHz for VHF or +5 MHz for UHF), and the necessary CTCSS tone. The article references resources like Repeater Book for locating repeaters and provides practical examples for initiating and concluding a basic repeater session, emphasizing clear identification and concise communication.

Phased array antennas are composed of multiple individual antenna elements that can have their phase and amplitude controlled to steer the main beam direction in real-time. They are used in radar, communications, and electronic warfare, and offer improved gain and reduced side lobes. A comprehensive document on Phased Arrays include techniques to increase the Antenna Gain and change the Radiation Pattern

The Loudoun Amateur Radio Group (LARG) of Loudoun County, Northern Virginia, was founded in July 1993. LARG is a family oriented club with a wide variety of activities and interests. Some of these activities include public service, emergency communications support, high altitude balloon radio, camera and video flights, fox hunts, contesting and radio sport DX-ing

Amateur radio courses teach that in amplitude modulation, sidebands arise. This can be proven mathematically, and nowadays with an SDR one can easily see them.

The Shrunken Quad antenna is a unique design that offers full-sized performance on the 10m and 15m bands while incorporating linear loading via a trap for operation on the 20m band. This design allows for effective communication in the HF spectrum, making it suitable for both casual operators and serious DXers. The quad configuration provides excellent gain and directivity, which is beneficial for contesting and long-distance contacts. Constructing the Shrunken Quad involves careful attention to dimensions and materials to ensure optimal performance. The antenna's compact nature makes it an excellent choice for limited space situations, allowing operators to enjoy the benefits of a quad without the need for extensive real estate. This project is ideal for amateur radio enthusiasts looking to enhance their station's capabilities with a versatile and efficient antenna system.

This document serves as a reference guide for pilots interpreting the symbols used on Instrument Flight Rules (IFR) Enroute Low and High Altitude Charts for both the United States and Alaska. It focuses on six key categories of information critical for safe IFR navigation and it includes a section dedicated to Oceanic Route Charts for the North Atlantic and North Pacific regions.

This page reports the last six daily MUF(3000)F2 plots recorded at Rome observatory by the AIS-INGV ionosonde. Provided Istituto Nazionale di Geofisica e Vulcanologia (INGV) Italy.

JJY is a time signal transmitter operated by the National Institute of Information and Communications Technology (NICT) in Japan. It broadcasts on two frequencies, 40 kHz and 60 kHz, and is used for time synchronization in Japan.

Explore the pivotal role of artificial intelligence in advancing emerging radio technologies, facilitating ubiquitous connectivity essential for sustainable development, the digital economy, and the Internet of Things, guided by ITU's harmonized regulations and standards.

This guide by F4ANN (2014) explains replacing the backup battery in a YAESU FT-757 GX when stored frequencies reset on power-up. The original CR-1/3N lithium cell (3V, 160 mA) can be substituted with a CR2032 (170 mA), which is cheaper, widely available, and easier to replace. The process involves opening the transceiver, carefully desoldering the old battery from the PCB, and wiring in a holder for the CR2032. Extra care is required with screws, connectors, and soldering. The author also replaced backlights and serviced the cooling fan. Future battery replacements are simplified to four screws.

This post discusses the Norcal 2N2/XX CW transceiver kit and provides suggestions for minor mods and parts substitutions. The author shares their experience assembling the kit and highlights the simplicity and joy of operating a QRP CW transceiver. The post also includes images and a list of recommended modifications towards the end. If you own or are interested in acquiring a Norcal 2N2/XX kit, this post offers valuable insights and recommendations to enhance your experience as a ham radio operator.

The 52 Week Ham Radio Challenge offers hams a year-long series of 52 challenges to test and improve their skills. Created by Fabian Kurz, DJ5CW, this project includes bonus challenges that can be substituted for missed or failed tasks. The challenges cover a range of topics and activities related to ham radio operation, providing a fun and educational way for hams to enhance their knowledge and expertise. Whether you are a beginner or an experienced operator, this challenge is designed to engage and motivate ham radio enthusiasts throughout the year.

We are devoted to the preservation, restoration, and on-air operation of antique Amateur, commercial, HB, and Military Radio equipment operating in the Amplitude Modulation (AM) mode. The Florida AM Group net is for amateurs everywhere, meeting at 6:30 AM Eastern Time on 3885 kHz every Sunday morning. Come back to the days of vacuum tubes and high-fidelity audio, when real radios glowed in the dark. No need to have vintage gear to join in, if it says AM join the net using the AM mode. Facebook at Https://www.facebook.com/groups/154845541219803

Operating an **Echolink** gateway on the 4-meter band presents unique opportunities for extending VHF communications, as demonstrated by the EI4FMG node. Situated at Fieldstown, Monasterboice, this gateway provides coverage across a significant portion of Ireland's east coast, leveraging a Tait TM8100 radio and an EI4JR Echolink interface logic. My own experience with similar setups confirms the importance of strategic site selection for maximizing reach, particularly with a 122-meter elevation above sea level. Access to the EI4FMG gateway, identified by node 57006, requires a **CTCSS** tone of 88.5 Hz, a standard practice for managing access and minimizing interference on shared frequencies. The system transmits with 15 watts of power and utilizes a Sigma CAT70 @5MAGL antenna, a configuration well-suited for regional VHF coverage. The gateway also features an auto-ID every 8 minutes, ensuring compliance and clear station identification. Users can interact with the gateway using various DTMF commands, allowing for connections to specific nodes, random repeater/link or conference nodes, and managing disconnections. These functionalities streamline the process of linking into the broader Echolink network, enabling local VHF operators to communicate globally through the internet backbone.