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Understanding current in loading coils

An Arduino based CW contest keyer addon, ideated and designed for the use in conbination with the K3NG Arduino keyer open-source firmware.

Ross distributing amateur radio equipment in Preston Idaho

Victor Valley ARC

Royal Belgian Union of radioamateurs Koninklijke Unie van Belgische Radio-amateus Union Royale Belge de Amateurs-?metteurs

QST Article on what you should know about matching networks for class C RF power amplifiers

"Shows who is ""active"" on VHF in EI, Solar Auroral and Tropo information, Vhf logs and maps."

Manufacturer of pultruded fiberglass shapes,

11 metres d.x. group northeast england.

The RAGS web site filled with information about the club and its happenings, as well as other ham info in the Syracuse area NY

low-noise amplifier for HF reception, amplifies signals 80 to 100 times between 0.15 MHz and 30 MHz. It will let you hear more signals with your RTL-SDR plus Ham-It-Up setup

Receive-only loop antennas have some nice response characteristics that make them ideal when used for reception of skywave signals.

Edwin H. Armstrong's foundational contributions to radio technology are presented, including the _Regenerative Circuit_ (1912), the _Superheterodyne Circuit_ (1918), the Superregenerative Circuit (1922), and the complete FM System (1933). This resource functions as a curated collection of historical documents and artifacts, many previously uncirculated, stemming largely from the _Houck Collection_. The site's purpose is to offer these primary source materials for study and enjoyment, rather than to retell Armstrong's life story, which is covered in works like Lawrence Lessing's "Man of High Fidelity" and Tom Lewis's "Empire of the Air." The collection emphasizes original documents, photographs, and equipment, all sourced from the Houck Collection unless explicitly noted otherwise. The site is structured for browsing chronologically, by selected year, or by highlight, allowing users to explore Armstrong's technical evolution. Document files are intentionally large to preserve readability and detail, while individual pages are kept concise to optimize loading times. The content provides direct insight into the technical development of radio communications.

This program simplifies the design of the single-ended Class E amplifier. Operation is intuitive and encourages "tuning" and exploration.

Examining the _Angle of Radiation_ and its impact on amateur radio operations, the resource provides insights into optimizing antenna performance for DX and local contacts. It features a design for SPOTTO, a direct conversion high-performance universal DSB transceiver, detailing its construction and operational characteristics for homebrew enthusiasts. Additionally, the site presents a 7-element VHF high-gain antenna design, offering practical schematics and expected performance metrics for those seeking enhanced gain on VHF bands. The resource also covers the development and popularity of the _FT8_ digital mode, highlighting its effectiveness in weak-signal conditions and its role in special event operations like the FT8DMC anniversary. It includes information on Hamfest India 2023 and the Lamakaan Amateur Radio Convention, providing dates and organizational details for significant Indian amateur radio gatherings. Technical articles on Direct Digital Synthesizers (DDS) VFOs and low-cost multifunctional frequency counters offer practical project ideas for radio amateurs.

Schematic diagram of the VLA 200 power amplifier by RM Italy

A Weather ATV Repeater project I am currnetly working on.

The Meteor Scatter tips and tricks described here are based upon more than 20 years of active MS operation

Independence FM amateur radio club

The JSCARC, located at NASA's Johnson Space Center, Houston, Texas, supports the U.S. Space Program and the International Space Station.

Amateur radio online store based in CA USA

The home page of the boca raton amateur radio association. we meet on every first tuesday of the month and operate the 145.290 repeater. Palm Beach County, Florida.

The main function of the Ugly Balun is to help eliminate rf currents from flowing on the outside of coaxial cable using the principle of choke action.

European supplier of radio communication receivers and scanners, transceivers, antennas, cables, connectors, GPS and accessories based in Prhaha Czeck republic.

A multiband coax trapped dipole for 10-80 meters bands by DF1PU

F.A.R.G. The Friends of Amateur Radio Group Home Page.A fraternal organization dedicated to the advancement of Amateur Radio. Many links , Club roster.

TAPR, an international organization dedicated to amateur digital communications, is pleased to present this collection of information about TAPR, via the World Wide Web.

This large, colorful wall map features current geographic detail and labels, grid squares, call sign prefixes, boundaries and more.

A Morse code TEXT-to-MIDI converter that creates a Morse code standard MIDI file from ASCII text.

Decibels: dB, dBA, dBC, dBV, dBm and dBi? What are they all? How are they related to loudness, to phons and to sones? This page describes and compares them all and gives sound file examples.

Understanding Amateur Radio NVIS Antennas and Propagation, derived from The ARRL Antenna Book and QST Articles

BRATS amateur television, amateur radio, and public service, Baltimore Radio Amateur Television Society

This web article by VK3BLG details the construction of an experimental 70cm (432 MHz) circularly polarized patch antenna, intended for satellite communication. The resource provides dimensions, feed point specifications, and impedance matching considerations for a single patch element, with discussion extending to array configurations for circular polarization. Construction involves a copper patch element on a dielectric substrate, fed via a coaxial cable. The design is based on information derived from AO-40 satellite antenna specifications, focusing on achieving circular polarization for satellite reception. The article includes specific dimensions for the patch and feed points, along with impedance values. Validation is implied through on-air satellite reception reports, with initial signal reports of **1 S-point above noise** for AO-40 beacons using a grid reflector, improving to **3-4 S-points above noise** with a 2-turn helical feed. The author references a _NanoVNA_ for impedance measurements and discusses the relationship between slot and dipole antennas in the context of patch design. DXZone Focus: Web Article | 70cm Patch Antenna | On-Air Satellite Reception | Circular Polarization

A motor tuned magnetic loop antenna that can work from 14 MHz to 30 MHz

Article on the Dentron MT-3000A antenna tuner and some good modifications by W1AN

Vacuum Tubes and Radio Tubes Our specialty. We carry over 5,000 radio and vacuum tubes in stock every day and we ship world wide. Tubes for industry, music, ham radio, the audiophile.

A new HF transmission protocol for Winlink 2000

An high gain long yagi antenna, seven elements, for six meters band

Easy to use award tracking software for ARRL, 10-10, CQ, HRN, OMISS, EPC, RAC and more.

Web Morse Runne is an online CW (Morse code) contest simulator developed by DJ1TF - Thomas Fritzsche. This tool allows users to practice their Morse code receiving and sending skills in a simulated contest environment. Key configurable parameters include CW speed, with options ranging from 300Hz to 900Hz, and RX bandwidth, adjustable from 100Hz to 600Hz. Users can also set a monitor level and simulate various band conditions. The interface includes counters for calls and QSOs per hour, along with a timer. Pre-defined function keys are available for common contest exchanges such as F1 (CQ), F3 (TU), F6 (B4), F7 (?), and F8 (NIL). The simulator is designed for ham radio operators looking to improve their CW contesting proficiency.

ICNIRP is a calculator software that allows you to determ safety distances for many know amateur radio antennas with respect to ICNIRP limits developed by DL9KCE

Amateur Radio Web based logbook, initially linked to ham radio deluxe log and now supported by other popular log book programs, permit to publish a searchable contacts log, maps logs, and display a timeline of contacts.

Just Learn Morse Code is a free windows software designed to make it easy to learn Morse code, as well as improve the skills of those who already know the code

The Skywide Club, established in 1952, has been serving the amateur community for four decade

Homebrew GMRS 3 Element Yagi yagi for 462-467 MHz

This is the official site of the Milan branch of A.R.I.

Shows which beacon is currently transmitting on the selected radio band Displays information about transmitting beacon Informs about direction and bearing from users position towards transmitting beacon

The Research and Documentation Center for the History of Radio Communications and the Electronic Media (our full name) is the world's biggest organization to collect, save, research and present whatever relates to the history of radio communications, particularly amateur radio and broadcasting

Professional award management program, currently only in german

A review of the Yaesu FT-857D mobile transceiver by yo3hjv