Radio Communication Technology Blog

Near Vertical Incidence Skywave (NVIS): The Definitive Guide to Reliable Regional HF Radio : Learn how NVIS (Near Vertical Incidence Skywave) enables reliable short-range HF communication, including propagation, frequencies, and use cases.

ADSBee 1090: An Open-Source ADS-B Receiver Built for Modern Aviation Tracking : A detailed look at ADSBee 1090 open source ADS-B receiver, covering features, architecture, variants for aviation tracking embedded projects. Aircraft tracking has long been dominated by SDR dongles and proprietary receivers, but the  ADSBee 1090  introduces a different approach. Designed as a compact, open-source 1090 MHz ADS-B receiver, it targets aviation enthusiasts, developers, and educators who want reliable decoding without the complexity of traditional SDR setups. Instead of relying on wideband sampling and heavy post-processing, the ADSBee 1090 is purpose-built to decode aircraft transponder signals efficiently, making it well suited for embedded systems and always-on ground stations

Evolution of the ATS Mini: A Technical Deep Dive into V1 through V4 : Explore the evolution of the ATS Mini DSP receiver. Compare V1, V2, V3, and V4 models, featuring shielding, Si4732 enhancements, and Hi-Z circuit improvements.

Just came across a very nice DIY project on building a high sensitivity regenerative receiver using a 2N7000 MOSFET. The design shows how a simple regenerative circuit, using positive feedback and a single active device, can achieve impressive sensitivity on medium wave and shortwave bands. The article explains coil winding, tuning, regeneration control and practical construction tips, making it ideal for radio amateurs, students and experimenters who want to understand classic receiver principles with modern, easily available parts. It is a great weekend build for anyone interested in analog RF, homebrew receivers and learning how regeneration can rival much more complex superheterodyne designs in sensitivity when carefully adjusted. The full project is available at https://vu3dxr.in/build-a-high-sensitivity-regenerative-receiver-with-2n7000-mosfet/

Working on the LARCSET v3.0?  The Bitx20 community is full of brilliant minds, and many of us have faced similar challenges when putting this version together. I’ve compiled the most frequent problems and their proven solutions into one guide to help fellow builders. From troubleshooting common errors to fine-tuning for better performance, this post is meant to be a "workbench companion" for your project. Read more here: https://vu3dxr.in/building-the-larcset-v3-0-real-world-problems-and-proven-fixes-from-the-bitx20-community/ Let me know in the comments what your experience has been with the v3.0 so far! 73! 📻 #HamRadio #Homebrew #Bitx20 #RadioBuilder #VU3DXR

Radio Waves Weekly Digest — Issue #001 : Curated digest of recent and useful links related to SDR, ham radio projects, tools, and online listening resources — all from blogs, forums, community posts

The  40m  vertical antenna  is one of the most effective solutions for amateur radio operators who want strong DX performance without needing a full-size tower or large open yard. The 40-meter (7 MHz) HF band is prized for its reliability—offering both daytime regional communication and long-distance propagation at night. Yet, a full quarter-wave vertical requires around 10 meters of height, which can be impractical in residential areas. That’s where a base-loaded 40m vertical antenna comes in—shortened to just 3.4 meters tall, it uses a coil at the base to achieve electrical resonance, allowing operators to enjoy 40m contacts from almost anywhere.A practical solution is a base-loaded vertical antenna, which uses an inductive loading coil at the base to achieve electrical resonance with a shorter radiator. The design shown above, originally credited to PY7NQ, is a compact yet efficient vertical antenna optimized for 40m HF operation. This antenna is a base-loaded quarter-...

Series Modulated AM Transmitter : A series modulated AM Transmitter is a type of radio transmitter that uses amplitude modulation (AM) to transmit audio signals over a carrier wave.

Check out this neat DIY project: a simple microphone compressor using the LM1458 op-amp —perfect for improving audio clarity and level consistency in amateur radio and audio projects. Great for homebrewers looking to add professional-sounding compression with minimal parts! 🎙️🔧 👉 https://vu3dxr.in/microphone-compressor-using-lm1458/

Discover more Amateur radio ham radio amateur radio Ham Transmitter transmitter radio Radio Mini rádió SI4732 Antenna The  Mighty Mite 40 Meter QRP  CW Transmitter  is a legendary low-power Morse code transmitter widely built by amateur radio operators for portable, minimalist, and educational operation. Operating around 7.023 MHz, this compact rig delivers approximately 5 watts RF output, making it ideal for QRP (low power) CW contacts on the 40-meter band. Mighty Mite 5W Crystal Controlled QRP CW Transmitter

Building End Fed Half Wave antenna (EFHW) for 40M – 10M : Learn how to build an End fed half wave antenna EFHW for 40m-10m bands with detailed specifications, including the 34 uH loading coil, 1:49 UNUN balun.

Flipper Zero – A Comprehensive Technical Guide : The Flipper Zero is a portable multi-tool device designed for cyber security professionals, penetration testers, hardware hackers, and radio enthusiasts. The  Flipper Zero  is a portable multi-tool device designed for cyber security professionals, penetration testers, hardware hackers, and radio enthusiasts. Launched through a successful crowdfunding campaign, this compact device has gained significant attention in the security community for its versatility and educational value in understanding various wireless protocols and digital systems.

Getting Started with FreeDV: A Beginner’s Guide to Digital Voice on Amateur Radio : Learn FreeDV digital voice for amateur radio. Beginner's guide covers setup, equipment, modes, and making your first contact using open-source software. If you’re an amateur radio operator looking to explore digital voice modes beyond the usual FM repeaters,  FreeDV  offers an exciting opportunity to experiment with open-source digital communication. This guide will help you understand what FreeDV is, why it matters, and how to get started with this fascinating mode.

Microphone Preamplifier with Diode Clipper for SSB Transceivers : Learn how to build high-performance microphone preamplifier featuring a diode clipper. This guide breaks down transistor stage and 1N914 limiting mechanism

J-Pole Antenna Using 300 Ω TV Ribbon Line : Simple 300 ohm twin-lead J-Pole antenna for 2-meter ham radio. Lightweight, no radials, easy to build, and ideal for portable, emergency, and home use. The  J-Pole antenna  made from 300 Ω TV twin-lead is a simple, lightweight, and very effective antenna for VHF operation, especially for the 2-meter amateur band. With no ground radials required and an easy feed arrangement, this antenna has become popular for portable use, emergency setups, apartments, and antenna-building events. The attached diagram illustrates a proven design that has been successfully built and tested by many amateurs.

VHF Collinear J-Pole : The DIY Super J-Pole Antenna : Take your VHF/UHF station to the next level with DIY Super J-Pole guide. Learn how to build this collinear antenna for maximum gain and clear long communication

Housing the LARCSet: A Community-Designed 3D-Printed Enclosure : A detailed look at a 3D-printed enclosure for the LARCSet transceiver, featuring Peter Marks’ open-source design and real-world build photos by Michael VE3WMB.