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New and refurbished test and measurement instruments

Gao engineering offers a wide range of affordable, popular and reliable rfid products, dsp, arm and other microprocessor evm and development boards, ides, universal programmers, emulators, dsp learning systems, micro-network terminals, test and measurement products for engineers.

Somalia

The South Alabama Radio Club is located in Covington County, Alabama in grid square EM61

Technical supplement manual of the Yaesu FT-8800R in english

Civilianized and Militarized HF antenna systems for Portable, Base, Mobile, Manpack. Antenna manufacturer based in MO USA

The Colorado AMSAT Net Page

An overview of coax cable often called coaxial feeder or RF cable, used to feed antennas and deliver radio frequency power from one point to another

Some things I've discovered about learning and operating CW by Chris Kantarjiev K6DBG

SW Radio Africa is the independent voice of Zimbabwe broadcasting on the short wave

The Microsniffer is a fully autoranging VHF or UHF sniffer which has been designed for those who are foxhunting on a budget.

The Rochester VHF Group, the oldest VHF-Oriented club in the World

Designing a beacon keyer that transmit the relative output power along to call sign.

Designed to handle audio signal interfacing as well as transmit/receive switching Reviewed by Steve Ford, WB8IM

Radio Interferences, QRN, or noise, information by W8JI

The Indianapolis Police Scanner on Broadcastify allows users to listen to live police radio transmissions from Indianapolis. The website provides access to emergency communications and public safety broadcasts.

A presentation of the Yagi Antennas, and other interesting tid-bits by Brian Mileshosky. The document provides an in-depth exploration of the Yagi-Uda antenna, detailing its historical development, design principles, and performance characteristics. Originally described in the 1920s, the Yagi antenna features a driven element and parasitic elements, including reflectors and directors, which collectively determine its behavior. The document highlights how element lengths, diameters, and spacing influence gain, impedance, and directivity. It also discusses the antenna's reciprocal nature and presents data on typical gain values for various element configurations. Additionally, the text covers practical considerations, such as the construction of a "Tape Measure Yagi" for amateur use, and touches on related antenna types like dipoles and their application in Near Vertical Incident Skywave (NVIS) communication.

Changing band selector to a Kenwood TL-922 power amplifier by IW1PUR in italian

Article on setting up a shotened beverage antenna with picture and setup notes by VE1ZAC

Two find dipoles one for 75/40/20 and the other for 20/15. These 2 dipoles are at right angles to each other and the 20/15 dipole is located about 6 feet below the 75/40/20 fan dipole.

Depiction mapping software can download and integrate maps, elevation plots, weather data, situation reports, damage assessments, volunteer movement, and more. It interface with your APRS ssystem

Heathkit SB220 refurbishing by PA5CA

The TransWorld Antennas TW4040 The Adventurer Monobander™ is a portable HF antenna designed for rapid deployment in field operations, including **SOTA** and **POTA** activations. This manual details the antenna's assembly, tuning procedures, and operational guidelines for optimal performance on the 40-meter band. It outlines the specific components, such as the telescoping whip and base unit, required for proper setup. Instructions cover mast erection, radial wire deployment, and impedance matching to achieve a low **VSWR** across the designated frequency segment. The document also provides guidance on antenna orientation and environmental considerations for portable use. It specifies the antenna's power handling capabilities and physical dimensions when fully deployed and collapsed for transport.

Presentation about finding, restoring, updating and operating vintage Ham Radio by K4QKY and Bill Call, KJ4W

Handcrafted Accessories for the shack by W2ENY includes Full range headphones with a mic, computer interfaces, mic ptt adapters

Designing your own QSL card is now easier than ever. This is a Program that helps you design and then Print your QSL cards filling them automatically with QSO data.

How can the current "flowing" out of the top of a mobile loading coil be greater than the current "flowing" into the bottom of the coil?

This R.F. current meter was developed to assist in measuring line currents in balance feed lines as used in the All Band HF Antenna.

Tait electronics provides advanced and reliable voice and data radio communications products and solutions, specialising in customised solutions for organisations worldwide.

WinXXDataConverter is a Windows GUI application that will convert files between the various formats used by Win92, Win93, Win95, and Win96.

Tips and tricks to start working Meteorscatter with WSJT. Author: PE1AHX

All risk ham radio insurance plans

Serving Columbia and Greene Counties of New York State

Manual of the BD-35 Dual Band VHF UHF RF power amplifier by Mirage Amp

The Short Mountain Repeater Club (W4YXA) maintains an open repeater operating at 146.910 MHz using a negative offset (146.310 MHz). The repeater is located about 60 miles SSE of Nashville, Tennessee

This project involves the construction of a 5 Watt Morse code beacon transmitter that operates in the 28.200 to 28.300 section of the 10 Meter Amateur Radio band. The beacon controller uses an Arduino Uno microprocessor board to produce the three signals that control the transmitter.

How to setup and install custom filters, usually inrad, into Yaesu FT 857 and FT 897 transceivers

A distributed capacity coaxial dipole antenna. The antenna is very broadbanded with a very flat swr on all band when setup of the antenna is done at the proper lenght and height.

Gnerate morse code at various speeds and with lots of different types of content, everything from individual letters up to a full QSO.

Operating a ham station often involves encountering radio frequency interference (RFI), RF feedback, or RF burns, which are frequently misattributed to poor equipment grounding. This resource meticulously dissects these assumptions, asserting that RF grounds on the operating desk often merely mask more significant system flaws. It identifies five primary causes for RF problems, including antenna system design flaws, proximity of the antenna to the operating position, DC power supply ground loops, equipment design defects, and poorly installed connectors or defective cables. The content emphasizes that issues like "hot cabinets" or changes in SWR when connecting a ground indicate substantial RF flowing over wiring or cabinets, a phenomenon known as common-mode current. The article provides detailed explanations of common-mode current generation, particularly from single-wire fed antennas like longwires, random wires, and OCF dipoles, which inherently present high levels of RF in the shack. It also illustrates how vertical antennas, lacking a perfect ground system, can excite feed lines with significant common-mode current. Through simulations, the author demonstrates how a dipole without a proper _balun_ can cause RF problems at the operating desk, showing current patterns and voltage distributions on feed line shields. The discussion extends to the proper application of _RF isolators_ and _ferrite beads_, clarifying their role in modifying common-mode impedance on cable shields and cautioning against their use as a band-aid for fundamental system defects. The resource advocates for correcting the actual source of RF problems, such as antenna system issues or poor connector mounting, rather than relying on internal shack grounding or isolators. It highlights that properly functioning two-conductor feed lines, like coaxial or open-wire lines, should result in minimal RF levels at the operating position, even without a desk RF ground. The author shares personal experience, noting that his stations since the late 1970s have operated without RF grounds at the desks, relying instead on proper antenna system design and feed line integrity.

The Radio Reference Database for United States

Batterieries for ham radio handheld radios and more

Handcrafted sending instruments for the Morse enthusiasts. K4VIZ Morse keys and paddles manufactured by K8UL.

Converting a HyperDawg to an antenna launcher

QST Green Radio Round-up from April 2006

Mobilinkd Bluetooth APRS TNC. With your radio, your Android phone and this TNC, you have everything you need to get started with APRS.

Explains the fundamental principles of Software Defined Radio (SDR) and Digital Signal Processing (DSP) within the amateur radio context, serving as an initial entry point for hams interested in these technologies. It covers the architectural shift from traditional analog hardware to software-centric radio systems, detailing how digital signal processing algorithms are applied to modulate, demodulate, and filter radio signals. The resource compiles a list of external links to _white papers_ and project pages, offering further technical depth. This page provides a foundational understanding of SDR/DSP, enabling operators to grasp concepts like direct sampling and quadrature mixing. It references various projects and discussions, allowing users to explore practical implementations and theoretical underpinnings. The curated links direct users to resources that might cover specific SDR hardware platforms or software applications, facilitating deeper research into the subject.

Site officiel du world lighthouse on the air award - official web site for wlota award

A sharewave windows logging program for the ARRL 10 meter contest by N3FJP

The CSV19 is an homemade antenna launcher project. In this article you can find pictures, drawing, and material list