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LA3ZA on magnetospheric ducting as an explanation for delayed signals on 3.5 MHz

Home made LF converter, listen to signals below 300 KHz

NOAA Satellite Signals With a PVC QFH Antenna and Laptop, this website also link to a github where you can find files and supporting documentation for constructing a QFH Antenna

Morse Code Decoder for Android based on the algorithms implemented in CW Skimmer. Morse Expert decodes Morse Code audio to text. It is optimized for decoding weak, fading signals in the presence of interference, especially on the Amateur Radio bands. The input audio might come either from the built-in microphone or from another device, such as a radio receiver.

This antenna is designed for stations having a difficult time putting a decent signal on 160M from small or CC&R d lots. It is a 24.5 ft. vertical antenna, made from three 10 ft. PVC sections bolted together, and half wavelength of antenna wire helically wound around the PVC sections.

A guide to properly use FT8 ALC and power when transmitting in FT8 Mode. Incorrect usage of power and audio from your computer may cause unreadable signals and transmit harmonics that can didturb other signals.

An excellent guide to operating FT8 mode available in English, German and Czech that cover several aspects of the FT8 operations. Includes and exaustive guide to how configure FT8 software, how to conducto a QSO and how to operate DXPeditions in FT8 F/H mode. Covers aspects of FT4 contesting operations and interfacing with logging programs

An exaustive document on frequency multipliers with a particular attention on ways to generate high frequency signals for microwave

Single antenna with multiple polarization for diversity, diveristy receivers and propagation effects on signal polarization

Article on propagation basics. The ground wave used for radio communications signal propagation on the long, and medium wave bands for local radio communications

The Badger Contesters is a club of like-minded hams who are interested in VHF/UHF/SHF weak signal communications. Our geographic focus is Wisconsin, however hams in Northern Illinois, Michigan's UP, and Eastern Minnesota are welcome to join us.

overview of radio signals and radiowave propagation and how different areas of the atmosphere affect radio communications.

Signal marker for the microwave bands

Weak Signal Audio 160m, choosing a headphone for weak signals reception

Experimental Stations Run by W1TAG WD2XES has been used to study LF antenna design, propagation and communication modes. Signals from WD2XES have been copied as far away as Russia.

Use your Smartphone as an Oscilloscope to visialize signals from 150 Hz to 15kHz and as a Signal Generator to generate sinusoidal, square and triangular signals up to 15kHz

A tutorial on how to setup a receiver capable to decode SSTV signals with a small RaspberryPi version 2 and a RTL-SDR dongle. The author explains how to install the needed software to interface the RTL-SDR and a step by step guide to install the QSSTV software used to decode the signals.

Microwave Signal Processing Components and Subsystems, from design to manufacturing.

Microprocessor based interface designed receives a signal from a Morse key, processes it, and re-transmits it to the radio. A microprocessor in the circuit is pre-programmed with a proprietary algorithm which makes a number of measurements and adjustments to the less percise human generated code.

Using a simple calculation, measure the distance between Earth and the Moon with the help of a local amateur radio station

This project takes after the VGA-to-Scope converter by using composite video rather than VGA signals to create a display on an oscilloscope.

This page contains Contributions to a Discussion on the Moon-Net about the Application of Digital Signal Processing (DSP) Methods in Moonbounce.

2-Meter Weak-Signal Enthusiasts

WSJT-X is an experimental version of WSJT implementing JT9, a mode designed for making QSOs under extreme weak-signal conditions

When one starts in amateur television, one begins with a small simple transmitter and a small camera. But very quickly, one needs to transmit audio signals with the pictures, then comes a second camera

Showcasing innovative RF solutions, Hofi Hochfrequenztechnik manufactures high-quality _antennas_ and RF switches. Their products, including the **versatower** and **fritzel** brands, cater to both casual operators and serious DXers. With a commitment to performance, Hofi's offerings enable operators to achieve optimal signal gain and reliability in various conditions. The company's expertise in antenna design ensures that users can effectively communicate across _HF_ bands, enhancing their overall operating experience. Whether setting up a new station or upgrading existing equipment, Hofi provides essential tools for successful ham radio operations.

A microprocessor based interface designed to go between a standard Morse code key and a radio transmitter. The circuit receives a signal from the key, processes it, and re-transmits it to the radio.

From 1921 to 1924, radio amateurs experimented with transmitting across the Atlantic. Everyday Engineering magazine organized the first sending test with English amateurs prepared to listen for signals from the US

An article describing basic concepts of antenna radiation, and in particular directional antennas like Yagi antennas or Quad antennas and how they determine the direction or signals.

The wire antenna described in this page provides much stronger signal strength while staying within the concept of a dummy load antenna.

Frequency Counter w/Selective Power Measurement, Microwave Sythesized Signal Generator

Manufacturer of low cost RF signal generators and portable measuring instruments.

Active Receiving Antennas, designed for reception of shortwave, mediumwave and longwave signals and VHF/UHF signals

Available worldwide can be used as Arduino Shield or plug it in to you PC , or with a bluetooth adapter connect to Android. With a highly optimized software, KAI200 brings you: a. Antenna analyzer form 1 up to 200 Mhz; b. WSPR transmiter (set up by serial terminal); c. Square Wave Signal generator KAI200 is all you need for your radio whatever it is Yaesu, Icom, Kenwood or Drake and DIY projects.

This FM wireless mike can transmit voice signals to any FM Radio receiver 100 meters away.

How to setup a band-tracking panoramic signal display to work along to your transceiver.

Do you want to see how your FT8 signals are being received in the other parts of the globe?

Code Synthesizer for 2-way Radio Signaling works on Windows XP and Windows 7

Starman Electric manufactures DataBridge wireless RF modem modules for easy point-to-point wireless data transmission of analog, digital, and serial RS232 UART signals.

Several national physics laboratories operate radio transmitters that broadcast a time code signal.

Article about tropospheric propagation and the way in which radio signals at VHF and above propagate over greater distances than strictly line of sight in the troposphere

The video delves into the fascinating science behind antennas, which are crucial for receiving and transmitting electromagnetic waves. It explains how antennas convert electric signals into electromagnetic waves for transmission, and how they operate through the oscillation of positive and negative charges in dipole arrangements. Practical antenna implementations, such as dipole antennas for TV reception and Yagi-Uda antennas with reflectors and directors, are also discussed alongside modern dish TV antennas with parabolic reflectors for signal processing. It's a comprehensive overview of how antennas work and their significance in communication technology.

Antuino is an accurate instrument that can be used in the field to measure SWR, field strength, modulation, etc. In the lab, it can be used to sweep filters, measure gain, distortion, frequency response, etc. It works upto 150 Mhz. On the third harmonic, it is usable on 435 Mhz band as well (with reduced sensitivity).

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.

Virtual Signal/One Radio Museum

The AA4F Key Contact Cleaner is designed for maintaining key contacts, ensuring reliable operation in 2-way radio communications. **Regular use** of this cleaner can significantly improve contact performance, reducing the risk of intermittent signals. It is particularly effective for cleaning contacts on various key types, including _straight keys_ and _paddles_. Proper maintenance extends the lifespan of your equipment, ensuring consistent operation during contests and DXing activities. Users report improved key responsiveness and reduced key chatter, which is crucial during high-pressure operating conditions. Regular cleaning can prevent oxidation and buildup, which can lead to erratic key performance. This product is essential for serious operators who rely on their equipment for successful communication.

Sending and receiving text with Morse code light pulses across the room is a fun and cheap project you can do on a Raspberry Pi or Arduino or any other microcontroller. This post explains how I did it, and how you can do it too.

OpenHamClock is a modern, open-source dashboard for amateur radio operators, designed as a web-based successor to the original HamClock. Deployable locally on a Raspberry Pi or via the cloud, it centralizes essential DX operations into a single, intuitive interface. At its core is an interactive world map that visualizes real-time DX spots, signal paths, satellite tracking, and POTA activators. The software seamlessly integrates critical tools like WSJT-X, DX Cluster, and PSKReporter for monitoring digital traffic. Additionally, it provides vital environmental data, including real-time space weather indices, solar activity, and personalized HF propagation predictions. With customizable themes and a modular architecture, OpenHamClock offers modern operators comprehensive, at-a-glance situational awareness of global radio conditions

A blog by W1REI dedicated to ham radio hobby

The problem with making your own trapped HF antennas is usually getting the coaxial traps tuned to frequency. This article explains a method using a RF signal generator at +10dBm output into the coaxial trap.