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Radio Society of Great Britain

Live Fire/EMS feed from Eastern King County, WA as dispatched by Eastside Communications

How to build a phasing harness for stacking antennas

Dedicated to the RTTY contesters worldwide by DK3VN, contest rules and summaries,

This resource provides a detailed historical record of satellite downlink frequencies, systematically organized by both frequency range and the satellite's launch year. It presents extensive listings covering segments from 8 MHz to 9000 MHz, including specific breakdowns like 136-137 MHz and 1600-2200 MHz. The data is segmented into distinct frequency blocks, offering granular information for various bands. The content delineates frequencies for satellites launched across several decades, with specific sections for years such as 2004, 1999, and extending back to 1967. This chronological organization allows for tracking the evolution of satellite communication frequencies over time. The resource serves as a reference for identifying operational downlink frequencies of historical space assets, which is particularly useful for satellite enthusiasts and those interested in _space tracking_ or _vintage satellite_ communications. The utility of this compilation lies in its specific historical data, providing a unique perspective on past satellite operations and frequency allocations.

Amplifier repair and conversion, specialize in converting HF amplifiers to operate as monoband amps on 50 MHz

October 2000 Ham radio dx-pedition

Stop common-mode current when transmitting with an end-fed antenna. Unbalanced antennas are very prone to currents on the outside of the coax.

Total Internet Linking information...

All about stacking and matching yagi antennas.

Stacking principles, with homebrew coax- and power-splitters by DK7ZB

The _ISS Detector_ Android application, with over 5 million downloads, offers precise predictions for visible passes of the International Space Station. It notifies users minutes before an overhead pass, integrating local weather conditions to ensure optimal viewing opportunities. The core functionality focuses on the ISS, but in-app purchases extend its capabilities to track other celestial and artificial objects. Optional extensions, available via in-app purchase, allow users to monitor dozens of amateur radio and weather satellites, providing real-time transmitter information and Doppler frequencies. Additional extensions cover _Starlink_ satellites, the _Hubble Space Telescope_, rocket stages, bright satellites, comets, and planets, expanding the scope beyond the ISS to a broader range of observable space phenomena. The app's interface is designed for ease of use, displaying pass times, directions, and elevation. It adapts predictions based on the user's GPS location, ensuring accurate local forecasts. The latest update, dated April 3, 2026, includes corrections for magnitude values and various speed and stability optimizations.

Taking the Raspberry Pi 2 for a Test Drive with GNU Radio. Installing GNU Radio and receiving aircraft radar with a USB TV tuner

A 109 pages presentation in PDF File by Jim Brown K9YC on techniques in operatint the top band from a small lot.

High Speed Multimedia Radio Introduction by ARRL Working Group Chairman. Report of the High Speed Multimedia (HSMM) Working Group ARRL Board of Directors 2006 Annual Meeting January 22, 2004

The document explains the technical aspects of how the Internet Radio Linking Project (IRLP) works, focusing on the use of VoIP streaming software under the Linux operating system. It details the audio sampling, compression, transmission, reception, and playback processes involved in IRLP communication.

Kingsport Amateur Radio Club / Bays Mountain Radio Club , Serving Tri-Cities TN/VA Area, Useful Technical Links, Club Photos

AO-51 Operating guidelines and introduction

JSatTrak is a Satellite tracking program written in Java. It allows you to predict the position of any satellite in real time or in the past or future. It uses advanced SGP4/SDP4 algorithms developed by NASA/NORAD or customizable high precision solvers to propagate satellite orbits.

The CES Wireless Technologies website details a range of **GPS fleet tracking** solutions designed for mobile information systems. It highlights offerings such as dispatch and mapping software, Automatic Vehicle Location (AVL) systems, and mobile data display terminals. The platform also mentions support for Automatic Number Identification (ANI) and Continuous Tone-Coded Squelch System (CTCSS) functionalities, indicating integration with two-way radio communication protocols. Specific products include GPS tracking devices and associated software for fleet management, emphasizing features like real-time location monitoring and operational efficiency. The site positions itself as a manufacturer in this specialized domain, catering to commercial and public safety sectors requiring robust mobile data solutions. While the page title mentions "Ham Radio Directory" categories, the content primarily focuses on commercial GPS and fleet management technologies, not amateur radio applications. The listed products are geared towards professional mobile radio (PMR) environments rather than typical ham radio operations.

Fellowship for all Amateur Radio Operators of Rockingham County. Home of the N4IV repeater system. Licensing classes, testing, ARES, and Skywarn

For over 50 years, Communications Specialists Inc. has been a cornerstone in specialized radio frequency solutions, initially gaining prominence with their **CTCSS** and **DTMF** tone signaling products widely used in amateur radio repeaters and commercial two-way radio systems. My own experience with their tone boards in various repeater builds confirms their reliability and ease of integration, a testament to their engineering. The company's legacy in tone encoding and decoding is well-established, providing robust solutions for access control and selective calling. Beyond tone signaling, Com-Spec has diversified into niche markets, including wildlife telemetry, pet tracking collars, and specialized tracking systems for model aircraft and rocketry. Their product line features compact transmitters and receivers designed for specific tracking applications, demonstrating a commitment to precision and durability in challenging environments. While some legacy products are no longer available, Com-Spec continues to innovate, as evidenced by the new R-30M receiver, which ships within five days. This focus on specialized RF applications, from tracking Alzheimer's patients to law enforcement, highlights their unique position in the radio communications industry.

Kingston, Ontario, Canada A RAC Affiliated Club

N8VI\'s powerpoint on satellite keplerian elements.

The normal way to make a good balun is to wind a core with a bifilar winding about 8-10 turns, and then connect the coax to one side and the antenna to the other.

Fundamentals of operating on single sideband

The Icom IC-7300 is a groundbreaking Software Defined Radio (SDR) transceiver that revolutionizes the way amateur radio operators interact with the spectrum. With its large 4.3-inch color TFT LCD touch screen, users can easily navigate through various functions, including real-time spectrum scope and high-resolution waterfall displays. This allows for quick adjustments and enhanced signal awareness, making it easier to find and engage in QSOs. The touch screen interface provides a modern approach to radio operation, replacing traditional buttons with virtual controls that can be accessed with a simple touch. In addition to its user-friendly interface, the IC-7300 boasts advanced features such as IF-DSP filtering, audio scope functions, and a multi-dial knob that combines tactile control with touch screen flexibility. These capabilities enable operators to visualize signals and make precise adjustments to their settings, ensuring optimal performance during contests or casual operating. The IC-7300 is designed for both beginners and experienced hams, making it a versatile addition to any shack. Its innovative design and functionality truly embody the spirit of modern amateur radio.

A PTT switch from Home Depot parts

About SDR Radio, basics and a how to guide

Restored vintage amateur radio, shortwave & other electronics from the vacuum tube era! Specialists in restored Ham Radio boatanchors

Brookings Radio Research Club homepage, South Dakota

The Doppler Effect allows the distance between a satellite transmitting from space and a radio receiver on the ground to be measured by observing how the frequency received from the satellite transmitter changes as the satellite approaches, passes overhead, and moves away.

Making a CW QSO by John Shannon, K3WWP

Dopller effects on satellite tracking

BPQ32 allows a computer running under Microsoft Windows to act as a Node in a NET/ROM compatible AX25 network, and to support a multiuser Mailbox, or other similar applications.

Presents the Carolina DX Association's (CDXA) _Contest Corner_, a dedicated resource for amateur radio contesting activities. It features a curated contest calendar, linking to external resources such as the _WA7BNM Contest Calendar_ and the _ARRL Contest Calendar_, providing a broad overview of upcoming events. The page also details CDXA's internal contest programs, including the "CDXA DX King" and "CDXA DX King Classic" for 2026, with specific links for members to submit their scores. Furthermore, the resource integrates with _3830Scores.com_, encouraging CDXA members to submit their contest results and select the club affiliation for tracking. It provides a direct link to view aggregated scores from participating CDXA members, fostering club competition and recognition. The "CDXA Periodic Table of Contest - 2026" is also mentioned, indicating a structured approach to contest planning for the year.

Sixty-meter repeaters typically use a 1 MHz frequency separation between input and output, while 2-meter repeaters commonly employ a **600 kHz** split and 70-centimeter repeaters use a **5 MHz** offset. This article details the fundamental technical principles of amateur voice repeaters, explaining how they extend VHF/UHF communication range by receiving on one frequency and simultaneously retransmitting on another. It covers essential components such as receivers, transmitters, filters, and antennas, often situated on elevated locations for optimal coverage. The resource delves into the critical challenge of _desensing_—where the repeater's strong transmit signal overpowers its own receiver—and the engineering solutions employed, including antenna separation and the use of high-Q cavity filters. It also explores various control and timing systems, from basic squelch activation to more sophisticated microcontroller-based boards that manage functions like voice identification, time-out timers, and fault protection. Different access methods are discussed, including open access, toneburst, CTCSS subtone, and DTMF, each offering distinct advantages for managing repeater usage and mitigating interference. Furthermore, the article examines repeater linking, both conventional RF methods and modern internet-based solutions, highlighting how linking expands coverage and promotes activity across multiple repeaters or bands. It introduces less common repeater types such as 'parrot' repeaters, which use a single frequency and digital voice recording, and linear translators, capable of relaying multiple signals and modes simultaneously across different bands, often found in amateur satellites.

Article on 50 Mhz Yagi Antennas stacking by OH1ZAA/NN0Y

Benefits of stacking two HF antennas vertically

Kingston, Ontario, Canada A RAC Affiliated Club

King Conversions has extensive experience in amplifier repair and conversion King Conversions specialize in converting HF amplifiers to operate as monoband amps on 50 MHz

How to stack different band yagi antenna in a single tower

The new and current web presence of the Kings County Radio Club, in Brooklyn New York

Meet The Breakers is a unique exploration of the CB radio culture in the United Kingdom, hosted by Colin The Head. This series delves into the lives of various CB radio enthusiasts, showcasing their setups, stories, and the vibrant community surrounding this hobby. Each episode features interviews with notable figures in the CB world, providing insights into their experiences and the equipment they use. The program not only highlights the technical aspects of CB radio, such as antennas and signal checks, but also captures the personal stories that make this hobby special. From collectors of rare equipment to modern-day users navigating the airwaves, Meet The Breakers offers a comprehensive look at the diverse personalities that contribute to the CB radio landscape in the UK. Whether you're a seasoned operator or new to the scene, this series is a valuable resource for anyone interested in the world of CB radio.

ARDF IARU Region 1 working group

The Licking County Contest Group (LCCG) is a small group of Radio Amateurs in Licking County Ohio who enjoy contesting.

How to work the ISS using APRS Packet Radio

This is a synopsis of a talk presented to the Sydney VHF DX GROUP by VK2ZAB on how, when and why is convenient to build a Yagi antenna stack.

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.