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Associacao de Radioamadores de Amadora-Sintra Portugal

A collection of 450 MHz Cheap Yagis that have proven great portable operations, back-packing and transmitter hunts, and are something inexpensive you can throw up in the attic for that weak repeater

Article on common Classification of Spy Numbers stations.

A project to turn a Raspberry Pi into a very versatile tracker, digipeater and an iGate

Vacation style dx pedition as VK9X and VK9C

A list of links to semiconductor manufacturers, including direct links to their datasheets index page

Ultimax antennas manufacturer of amateur radio End-Fed and bazooka antennas made in USA

Coastal Amateur Radio is for hams south of the Fraser. Even if you live north of the Fraser you are welcome to join in. Hams who come together for the love of HF & VHF in the hobby.

Narrow-bandwidth Television Association devoted to all aspects of early television.

Flight cases manufacturer, plastic cases, waterproof Storm and Explorer cases plus padded bags, plasma screen cases, foam inserts and aluminium boxes.

GM4YEQ Galashiels and District Amateur Radio Society (GDARS)

SDR as an RFI site survey tool. This article will show how a site survey tool was built to use in RFI mitigation.

Master Callsign Database Editor allows to create and modify Super Check Partial database files used by many contesting programs in DTA and SCP formats. The files produced by Master Editor in DTA format can be used with CT, WriteLog, TRlog, SD, and others. The SCP versions of the produced files are for use with Win-Test, N1MM+, and others. Master Editor allows to create a callsign database from a separate log or from a set of logs in the Batch Import mode.

An online calculator for designing and evaluating capacitors based on the capacitor's area, separation, number, and dielectric constant

Solar and Heliospheric observatory

An FCP is not magic. It has no gain. An FCP improves an antenna system by replacing more loss with less loss. Some have been able to erect better wires in the air because the small size of the FCP allowed better placement of the antenna.

Encrypted messages, fancy technology, spies use them all to communicate, but sometimes the best way to hide is in plain sight. Right now, broadcasting across the airwaves around the world, are automated, anonymous shortwave AM radio stations that most governments won't acknowledge even exist, much less explain

This page describes an entirely simple, One-Knob matchbox that will match this antenna efficiently on 40, 30 and 20m, using a simple circuit that can be switched between series-resonant and parallel-resonant with just one banana jumper

Shipping case and custom foam specialists

If you want to have a closer look at the weather, you can download software and visually display data.

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

Provides a robust logging solution for amateur radio operators across multiple operating systems, QLog simplifies the process of recording contacts and managing station data. It leverages the _Qt framework_ for its graphical user interface and stores all QSO information efficiently in a local SQLite database, ensuring data integrity and accessibility. This design choice supports a streamlined user experience for daily logging activities. QLog supports essential logbook functionalities, enabling hams to accurately document their two-way radio contacts. While not specifically designed for high-speed contest operation, it serves as a reliable tool for general amateur radio logging, allowing operators to maintain detailed records of their on-air achievements and station activities. Its cross-platform compatibility, including Linux, Windows, and macOS, makes it a versatile option for a wide range of amateur radio enthusiasts seeking a free and functional logging application. The project is a fork from _7h0ma5/QLog_, indicating a continued development path.

IK5RUN, I5OYY I5IHE will operate from Praslin Is. Seychelles IOTA AF-024 respectly as S79UN S79YY S79LC Log Online and DX Spots Operations will start From Sunday 21st October 2012 till Sunday 4th November 2012

A homemade simple and inexpensive portable antenna support, handy for quick trips to the field and other portable operations

Online coloured Azimuthal Map Generator. By default, this map shows the current gray line. The parts of the Earth that are currently in the sun (i.e., daytime) appear brighter, and the parts of the Earth that are experiencing night appear darker

Alcatel Amateur Radio Association

The Western Washington Amateur Television Society (WWATS) is a group of amateur radio operators in the Puget Sound area with a common interest in amateur television

A.I.R.A. is chartered by the State of Illinois as a non-for-profit corporation and has been in existence over 21 years

TJ2TT log online and QSL request

Association Nationale de Television Amateur

An online morse code trainer application that allows to select the digits and play them at the wpm speed you desire. While decoding will evaluate the results and will indicate your proficiency level

Experiments on vertical antennas for HF bands.

A cavity backed antenna is a practical slot antenna tipically used in microwave applications

Washington IA

The antenna ground or earth system can be key to its operation whilst also being a key safety feature. This article is about grounding systems for antennas, covering different aspects of grounds made for antenna safety, or expressly for lightning or just to improve antenna performance, being ground an antenna component.

Amateur radio repeaters, often designated by an "R" number like _R6_ or _R5_, serve as crucial infrastructure for extending VHF/UHF communications range. This resource from Essex Ham explains the fundamental concept of a repeater, detailing how it receives on one frequency and simultaneously retransmits on another, typically with a 600 kHz offset for 2-meter repeaters. Understanding the input and output frequencies, along with the required CTCSS tone, is essential for successful access, ensuring your signal is processed and relayed across a wider service area. The article clarifies the importance of using the correct _CTCSS_ (Continuous Tone-Coded Squelch System) tone, often referred to as a sub-audible tone, to activate a specific repeater. It also touches upon the concept of _simplex_ operation versus repeater use, highlighting the benefits of repeaters for mobile and handheld transceivers. Proper operating procedures, such as listening before transmitting and keeping transmissions concise, are emphasized to maintain good amateur practice on shared repeater assets.

Analysis of flag receiving antennas using MININEC with focus on relation of size and atenna height by VE6WZ

High-performance rugged antennas and RF accessories such as magnetic mounts, RF coaxial gooseneck adapters, LNAs, BDCs, for law enforcment, military, maritime and video markets.

This presentation applies to HF / VHF / UHF antennas and is about 14 different type of antennas suitable for indoor od apartament installations

Enables Android users to operate various _miniVNA_ antenna analyzers via Bluetooth, USB, or Wi-Fi, providing a portable solution for RF measurements. The application supports full control over data acquisition, offering features like custom frequency range selection from 1 KHz to the VNA's full range, and automatic screen adaptation for diverse Android device resolutions. It facilitates intuitive, wizard-based calibration for both reflection and transmission modes, saving calibration data for different VNA types (Standard, Pro, Pro with Extender) to avoid repeated procedures. The software displays critical parameters such as SWR, |Z|, Return Loss, Phase, Rs, and |Xs| on 2-axis graphs or Smith charts, with multi-touch gestures for zoom and frequency shift. It includes a frequency generator mode with independent channels and attenuator control for the miniVNA Pro, along with a sweeper function. The cable data mode automatically calculates phase and loss, measures cable length from less than 1 meter to hundreds of meters, and includes a table of common coax cable velocity factors. An experimental X-tal mode measures resonance frequency, Rs, and Q. Data export options include CSV, ZPLOT, and S1P formats, with CSV import capability. The application also features an SM6ENG Audio mode for SWR tuning without visual reference and provides a miniVNA battery voltage indicator. It supports a wide frequency range, with the miniVNA Extender extending coverage up to **1500 MHz**. The application is compatible with Android version 2.2 and later, tested on devices like the _Galaxy TAB 7.7 P6800_.

Scottish ham radio society

Latest news from WIA also in podcast

The areas noted in the forecast have the necessary atmospheric conditions to produce tropospheric bending of VHF, UHF and/or microwave radio waves. Tropospheric bending extends the range of radio & TV stations well beyond their normal limit and thus increases interference amongst stations as well.

Operating on Airplane scattering. Scattering of radio signals by airplanes. An introduction to operating ariplane scattering, using aircraft to redirect RF that would otherwise be lost in space. Antenna Pointing, Doppler Shift/Digital Modes, using digital modes to operate airscatter.

All asian dx contest cw and phone rules and results of previous editions

The "DIY Telescopic-V Antenna £35" project showcases the creation of a budget-friendly, portable telescopic V-shaped antenna inspired by commercial designs. Using eBay-sourced telescopic whips and custom mounting solutions, the author documents their process, testing, and adaptations. Despite challenges like weather and missing tools, the antenna performed well across multiple bands, enabling successful QSOs. Future improvements include exploring loading coils and testing in better locations. The compact design offers versatility for amateur radio enthusiasts seeking an affordable and practical solution.

Construction tips of a basic wire antenna, the half wave dipole. Inverted V dipoles and effects of inverted v on radiation pattern.

Have you ever thought of setting up a portable HF station for an activity like the Field Day ?

All available frequencies & offsets configurations for repeaters can be downloaded as database for Kenwood MCP-2A memory channel programming software for TM-D710 & TM-V71. Zip file is no more available from the author, but the full table of frequencies is still online