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The Yorkshire ATV group promotes the use of Amateur Television in Yorkshire, UK and runs the ATV repeaters GB3YT and GB3YX.

Learn how to start using ham radio satellites for your DX contacts, PDF presentation by Dave Long

A circuit for a 5 milliwatts super QRP morse code transceiver by VE2ZAZ

The oscilloscope simulation shown on this website is based on the HAMEG HM203-6 20 MHz oscilloscope of Hameg GmbH in Frankfurt/Main, Germany

Pre-inked - re-inkable stamps

A Co-ax Trap Dipole For 40, 30 and 20 Meters or at last that was the intention

The County Hunting software, version **6.1**, is designed for amateur radio operators focused on USA-CA Award tracking and logging. This application supports _Windows_ environments and facilitates the import and export of ADIF files, enhancing QSL management by integrating electronic confirmations via LoTW and e-QSL. The software has been updated to align with the new award rules managed by MARAC, following the discontinuation of CQ magazine's involvement. Users can visualize QSLs post-scanning and benefit from enhanced ADIF import functionality. Version 5.4 introduced accelerated county searches via FCC databases, with filters for QSL confirmations and e-QSL enhancements. The software also includes a feature for backing up and restoring QSOs by LoTW confirmations. Visual County tools have been refined, offering improved map interactions and the addition of county flags. The software supports various digital modes including FT8, FT4, and SSTV, and includes functionality for PSK250 and 60m bands. The application is multilingual, with support for Italian, English, French, and Spanish, and provides automated updates and web-based county searches. DXZone Focus: County Hunting | ADIF | Windows | LoTW

Ham radio manuals in italian and english for several makers and products

KCAWG web site with lots of informations for local APRS operations by KU0G

San Diego Police scanner

Two-meter and aircraft band receiver specifically designed for RDF on foot, sold by Bryan Ackerly VK3YNG

The X80 multi-band HF vertical antenna, a commercial iteration of the Rybakov design, exhibits a physical length of 5.5 meters, or approximately 18 feet, and is constructed from aluminum tubing. It operates as a non-resonant vertical, requiring an external antenna tuner for impedance matching across its intended operating frequencies. The antenna's design incorporates a 1:4 UNUN at its base, facilitating a nominal 50-ohm feed point impedance for the coaxial cable. Performance observations indicate effective operation on 40 meters, 20 meters, 15 meters, and 10 meters, with reduced efficiency on 80 meters and 160 meters due to its relatively short electrical length for these lower bands. Comparative analysis with a G5RV dipole and a half-wave end-fed antenna reveals the X80 offers a lower take-off angle, beneficial for DX contacts, particularly on the higher HF bands. Field tests conducted with an Icom IC-706MKIIG transceiver and an LDG AT-100ProII autotuner demonstrate the X80's ability to achieve acceptable SWR across 80m through 10m. The antenna's compact footprint and ease of deployment make it suitable for restricted spaces or portable operations, though its performance on 80 meters is noted as a compromise compared to full-size resonant antennas.

Cloudlog is a web-based amateur radio logging application built with PHP and MySQL, supporting station logging activities from HF to microwave. It integrates with companion tools for CAT control and automation, offering a flexible solution for managing QSO data. The application provides a self-hosted platform for amateur radio operators to maintain their logbooks, facilitating interaction with various ham radio operations. Its open-source nature allows for community contributions and customization, enhancing its utility for diverse operating preferences. Originally started by Peter, **2E0SQL**, Cloudlog was designed to enable simple interaction with the Ham Radio Deluxe logbook using MySQL.

New York's Hall Of Science Amateur Radio Club.

Fabricates baseplate components, and provides hardware kits for DIY hex beam, spiderbeam and moxon antennas.

Expeimenting with DSP digital signal processing on Arduino

Radio Club Argentino

A really simple LF receiving loop antenna

An homebrew Lindenblad antenna designed specifically for LEOs reception.

A 50-ohm generator feeding a 50-ohm line connected to a _quarter-wave transformer_ (150 ohms) terminated in a 450-ohm load is analyzed to understand transient behavior. The paper meticulously tracks voltage and current waves, reflection coefficients, and power levels through a sequence of events, starting from quiescent conditions. It details how incident and reflected waves combine and interact at impedance discontinuities, illustrating the dynamic changes in impedance and SWR at various points in the system. The analysis reveals that the impedance at the interface between the 50-ohm line and the 150-ohm transformer changes from 150 ohms to **64.3 ohms** after the first reflected wave arrives. Subsequent reflections cause the impedance to asymptotically approach 50 ohms, reaching **53.22 ohms** after five wave terms. The study also examines the generator's reaction to transient SWR changes, noting that a 3:1 SWR can temporarily reduce generator output to 0.75 watts, but these effects are temporary and diminish as the system approaches steady-state conditions.

Tubes and antique radio buy and sell classified ads

Alan Applegate (K0BG) article on mobile oprtations

Kc2uoo review of the yaesu ft-450 in this youtube video

6 Meter 1/4 Wave Antenna by Mike Fedler N6TWW. A detailed article with pictures of construction details of this 50 Mhz antenna

Free windows morse code learning program. Whether you want to learn Morse code from scratch, never having heard a dit in your life, or you just want to speed up your copy for CW contesting, CW Teacher will help

A spiral antenna experiment for RTL SDR usage.

Quarter wave omni-directional spider antenna for 2.4GHz 802.11b

How to become a High Speed CW operator, summary of information by AH6NB

Assembling a Code-Practice Oscillator, a PDF by ARRL

A magnetic loops for HF pedestrian mobile project by VK3YE

A very portable Umbrella Dish for the A0-40 Satellite operation, by G6LVB

Assisting applicants in obtaining the various FCC-issued Amateur and Commercial Radio Operator licenses.

A simple antenna analyser for the HF spectrum with a built-in signal generator with 3-digit LED frequency display.

Repairing and restoring a Yaesu FL-2100Z amplifier

Software for analysis of guyed and self-supporting towers & poles

The Double Bazooka Dipole is a very efficient single band antenna which is very quite,and does not require the use of a balun. This antenna consists of coax (RG58) with the shield split at the center and the feedline attached to the open ends.

A comparison of multiband dipoles, including jumpered dipole versus fan dipole antennas, dipole fed by ladder line, resonant dipoles antennas. ARRL lab notes

High pass filter schematics for TVI and examples of finished filters

The ZS6BKW multi-band antenna, an optimized variant of the classic G5RV, is presented with detailed construction and tuning instructions. This resource outlines the antenna's design principles, which were developed by _Brian Austin (G0GSF)_ using computer programs and Smith charts to achieve optimal dimensions. It provides specific guidance on calculating and adjusting the lengths of the radiators (L1) and the matching ladder line (L2), emphasizing the critical role of velocity factor (VF) in achieving resonance. The article includes a step-by-step procedure for empirically determining the VF of ladder line using an antenna analyzer, ensuring accurate physical lengths for the matching section. It details the tuning process for the radiators, offering practical tips for incremental adjustments to achieve the best SWR curve. The resource presents SWR measurement results obtained with an _AIM-4170C_ analyzer across multiple bands, alongside predicted SWR graphs from an AutoEZ model. It confirms successful contacts on 80, 40, 20, and 17 meters, including a **17-meter DX contact** to Italy. EZNEC and AutoEZ models for the ZS6BKW antenna, covering 80 through 6 meters, are provided for download, allowing further analysis and customization. The document specifies component details, such as the use of Wireman 554 ladder line and #14 AWG THHN copper wire, and discusses the antenna's performance characteristics, noting high SWR on 15 and 30 meters but successful tuning on 6 and 80 meters with an external tuner.

We intend for this page to tell our story as well as be a resource for other "hams"

Telephone EMI, questions and answers on how to solve interference problems to phone lines

The resource details the construction of a homebrew 50-watt FET amplifier, based on Don W6JL's _QST Homebrew contest_-winning design from 2009. It functions as an afterburner for QRP transceivers, providing a **12dB** power lift. The amplifier utilizes IRFZ24N FETs and covers the 80, 40, 30, and 20-meter bands, with the 20m LPF extending to 17m. Key technical aspects include an FT37-43 transformer for the input network, a relay-switched 3dB pad for lower bands controlled by an _Arduino Nano_, and an RF-actuated T/R switch. The LPF board integrates four relay-switched filters rated for 50 watts, using capacitors with a minimum 250VDC rating. Performance measurements indicate a power gain ranging from **4.4dB** on 20m to 8.1dB on 80m, with a required drive power of approximately 5 watts. The article also discusses thermal management, current limiting considerations, and component sourcing.

A vertical antenna for Six Meters band

Low signal, noise-high AC gain preamplifier

Heathkit Icom Kenwood Power Transistors Ten Tec Yaesu spare Hamradio parts.

Pics and specifications

5000+ member discussion group for the low-cost series of SoftRock SDR receiver and transceiver kits.

Home Page of Ivan, 9H1PI, QRV from the island of Malta on 50 MHz.

Sounds from the 136 kHz band

A compact 2 element W8JK beam antenna for 20M to 10M bands by AF6SA