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How to Increase your CW speed article by George Allison, K1IG as published on QST

ASA international DX-group! Enjoy the pages!

A long wire balun by ON6MU

Electronically controlled HF antennas. General coverage. Top features on all ham bands. Very advanced materials and state of the art technology.

The Voice of America (VOA) website serves as a primary digital platform for its international news and information services, broadcasting in 44 languages. The resource presents a wide array of current events, geopolitical analyses, and cultural reports, reflecting a global perspective on news originating from the United States. Content spans various regions, including Africa, Asia, the Middle East, and specific country-focused reports from VOA's language services, such as VOA Uzbek, VOA Kurdish, and VOA Russian. The site features top stories, special reports, and sections like "All About America" and "VOA Explains," providing in-depth context on US-related topics and global issues. The VOA platform offers a continuous stream of updated news articles, covering political developments like government shutdowns, diplomatic relations, and international conflicts, alongside social and economic issues. It also includes sections for "Worth Watching" videos and "From VOA's Language Services," highlighting the breadth of its multimedia output. The content is designed to inform a worldwide audience, often presenting multiple perspectives on complex international events and US foreign policy, making it a significant reference for those monitoring global news and shortwave broadcast content.

Technical and modification information on Astron Power Supplies compiled from a number of different sources by Mike Morris WA6ILQ

Chip64 mp3 file

On-line log for 3XY1T Guinea DX Pedition 2016

Thierry LOMBRY, ON4SKY, develops in several technical articles the way to select a transceiver. His website includes also some in-depth reviews

How to Operate Ham Radio on a Linux Workstation

The rhombic antenna is a diamond-shaped antenna, suspended between 4 masts.

Two types of multi-functional Home-brew 6/8Amps - 20 Ampere variable power supplies by ON6MU

One of the most useful antennas in the repertoire is the Marconi or quarter wave grounded vertical antenna. Its invention made it possible to halve the length of antennas, simplifying communications, especially at HF and below.

DK7ZB- Moxons with Aluminium Tubes, plans for moxon antenna for 6 10 12 15 meters

Presents a dynamic, searchable database of shortwave broadcast schedules from around the world, enabling users to locate active stations or plan listening sessions based on scheduled transmission periods and frequencies. The resource details specific station names, such as _Radio Habana Cuba_, _Deutsche Welle_, and _All India Radio_, alongside their operational times and assigned kilohertz frequencies. It also incorporates a distance calculator, which leverages geographical coordinates to estimate propagation paths, though it notes occasional data inaccuracies leading to transmitters appearing in oceanic locations. The platform's development log highlights continuous updates, including the integration of new seasonal schedules like "A24 frequencies" and "B23 schedule," reflecting the fluid nature of shortwave broadcasting. It documents challenges with geolocation services, particularly concerning Google API changes that impacted distance calculations and required user-side browser configuration adjustments for optimal functionality. The site owner, VAXXi, frequently communicates these technical adjustments and database updates, often acknowledging user contributions and donations. Distinctively, the resource provides a historical perspective through its update archives, illustrating the evolution of shortwave listening over more than a decade since its inception in 2011. It also mentions specific events, such as the BBC adding shortwave broadcasts for Ukraine on 5875 kHz and 15735 kHz, demonstrating its responsiveness to global events impacting broadcast schedules. The site's commitment to user feedback is evident in its bug reporting and feature request mechanisms, contributing to its ongoing refinement.

This program demodulates the telemetry data signal transmitted by the AO-40 satellite (aka Phase III-D) using the PC sound card

Data Management for the RadioShack PRO-93/2053 Trunking Scanner

British based CW club, originally founded in 1938

Flash Movie describing HF (shortwave) radio propagation to beginners. Very helpful aid in understanding.

Listen online to NYPD Special Operations Division live radio audio feed.

Codec2, an open-source speech codec, targets low bit rate voice communication, specifically designed for digital radio applications operating within constrained bandwidths. The project focuses on achieving intelligible speech quality at data rates around 2400 bits per second, a critical parameter for efficient spectrum utilization in amateur radio. Its development addresses the need for robust voice transmission over channels where higher bit rate codecs would be impractical or inefficient. The resource details the technical specifications and implementation aspects of Codec2, including its underlying algorithms and performance characteristics. It provides insights into how the codec processes speech to achieve its low bit rate, outlining the various coding schemes and their impact on voice fidelity and error resilience. The information presented allows radio amateurs and developers to understand the codec's operational principles and its suitability for integration into custom digital communication systems. Applications for Codec2 extend to digital voice modes on HF and VHF bands, enabling more users to share limited spectrum resources. The project's open-source nature facilitates community contributions and widespread adoption, fostering innovation in digital amateur radio. It represents a significant effort to provide a freely available, high-performance speech coding solution for the amateur radio community.

The industry standard in all antenna products

50 MHz meteor scatter offers a unique opportunity for amateur radio operators to make long-distance QSOs, even when the band appears dead. Meteor scatter involves reflecting radio waves off the ionized trails left by meteors burning up in the upper atmosphere, typically around 105 km high. These trails can facilitate contacts over distances up to approximately 2,300 km. The technique is particularly effective during meteor showers, which increase the number of meteors and thus the chances of successful QSOs. However, random meteors can also be used to achieve contacts, especially on the 50 MHz band, where the longer reflection time compared to 144 MHz makes it easier to work meteor scatter. Operators should be prepared to make QSOs in short bursts, often lasting only a few seconds. The IARU Region 1 meteor scatter procedure recommends using 2.5-minute periods for telegraphy and 1-minute periods for SSB, though shorter periods can be arranged. For 50 MHz SSB, 15-second timing is often used to maximize the chances of completing a contact. The procedure involves specific timing for transmissions based on direction and requires both operators to confirm receipt of callsigns and reports to complete a QSO. Understanding the geometry of meteor scatter, including the optimal radiation angles and the concept of 'hot spots,' is crucial. These hot spots are areas where reflections are most likely to occur, influenced by the Earth's rotation and the path of the meteors. Proper antenna setup, including elevation control and beam direction, can significantly enhance the chances of successful meteor scatter QSOs.

Processing a single RTTY signal from a transceiver's 3-kHz audio, GRITTY employs _Bayesian statistics_ for superior decoding accuracy compared to traditional trial-and-error methods. This approach not only decodes 5-bit Baudot codes but also calculates the probability of error for each bit, enabling features like color-highlighting unreliable characters and smart squelching based on error probability rather than signal amplitude. This allows decoding of very weak signals while suppressing strong, undecodable interference, resulting in minimal garbage text. The program intelligently analyzes decoded text, comparing similar callsigns bit by bit and merging probabilities using the Bayes formula. This often allows GRITTY to determine the correct callsign and place it on the call stack even when all received copies are corrupt. The same methodology is applied to correct errors in exchange numbers and CQ/DE keywords, and to fix incorrect shift states. GRITTY offers an open API interface, documented in its Help file, for integration with other programs, allowing them to receive decoded data and mouse click events.

Basic information on the folded dipole antenna

A microphone preamplifier schematic for hand-helds by ON6MU

San Diego Repeater Association. We maintain oper ham repeaters throughout San Diego and Imperial County, California.

Big picture and detailed feature of the yaesu VR-5000 receiver

Optimizing DX chasing efforts, this software provides a refined approach to monitoring the DXCluster. It allows operators to configure specific filtering criteria, ensuring that only relevant DX spots are displayed, thereby reducing clutter and focusing attention on desired entities or bands. The application integrates alarm functionalities, notifying the user when a spot matching their predefined parameters appears on the cluster, which is particularly useful for working rare DX or specific band slots. Spot supports both macOS and Windows operating systems, offering a cross-platform solution for a broad user base. Its design emphasizes user control over the displayed information, moving beyond a simple stream of cluster data to an actionable intelligence system for DXers. This client aims to streamline the process of identifying and pursuing DX opportunities. While the software was previously a commercial product, the developer, K3NC, has retired and made registration files for DXBase 2007 available for free, along with a utility to generate registration keys for that specific version. This allows continued use of the DXBase 2007 logging software, though it's important to note the 64-bit OS compatibility modification required for generated registration files.

Alan yates vk2zay's ham radio website, homebrew construction, general electronics, high voltage experiments, amateur rocketry, and general geek stuff

An old post by John Doty about effects of noise in longwire antenna.

Cheap Antennas for the AMSAT LEO Kent Britain WA5VJB

This article presents a method of controlling preamps, antenna switching and polarization switching remotely without the use of control cables.

The Russian Internet Callbook, hosted at krasnodar.online.ru, offers a specialized lookup service for amateur radio callsigns within the Russian Federation. This online tool is designed to assist DXers and contesters in identifying contact information for Russian stations. The resource functions as a digital callbook, allowing users to search for specific callsigns and retrieve associated data, which is crucial for QSLing and verifying contacts. While the concept is to provide a comprehensive database for Russian amateur radio operators, the current status indicates a configuration issue, as the domain krasnodar.online.ru points to the server but the site itself is not configured. This suggests the service may be inactive or undergoing maintenance, impacting its utility for callsign lookups. The original intent was to serve as a key _DX resource_ for the region.

Logbuchprogramm, DOS and Windows Logbook for radio amateurs written by DK8AT

This article describes a project of asymmetrical hatted vertical dipole, a portable antenna that can be used for field day operations, sota, campings or even for fixed installations. This is a freestanding 20-10m antenna that is really easy to build, easy to tune and relatively easy to carry.

Design guidelines for Op Amp audio preamplifier circuits by Mike Martell N1HFX

Notes on Axial-Mode Helical Antennas in Amateur Service. Helix Basics, Modeling Issues, and Short Helical Antennas Over Perfect Ground

ARRL affiliated organization

St. Louis County Police Dispatch

An emergency service provided to the city of Mountain View, California and the surrounding communities in time of need.

This program will convert comma delimited ASCII files to ADIF format for import into a logging program that supports ADIF import. The program is intended to be used with comma separated text files produced with other logging programs or with spread sheet programs, such as Excel.

Search the J5T Log online DX Pedition to Guinea Bissau 2017

The Sarasota Emergency Radio Club, is an Amateur (Ham) Radio club in Sarasota, Florida, dedicated to provide emergency and public service communications.

DX Atlas - DX Locations of the World by QRZ.com

Group with thousand of memebers focused on NVIS antenna

Ham radio map database with search and logging functions. Currently in german only, run under Windows.

The two linear amplifiers are ment for use with QRP SSB/CW/FM/AM transmitters on the amateur bands 15 and 17 meters can be powered from a 12 volt DC supply by ON6MU

N1HFX article on adjustable voltage regulator

Collection of different techniques to homebrew PVC yagi antennas, including elements assembling, baluns and chokes, radiator box tips and tricks by dk7zb