DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
Ever wondered how old-school AM broadcasting works without complex multi-stage LC circuits? This technical deep-dive breaks down a minimalist, single-IC AM transmitter design that leverages an integrated crystal oscillator and a simple audio transformer to achieve high-level amplitude modulation.
Ever wanted to know when a storm is brewing miles away? I built this simple but surprisingly sensitive lightning detector using a handful of jellybean transistors and a ferrite rod. Here’s how it works and why it blinks on a single strike.
The release of the zBitx v2 has sparked intense discussion within the amateur radio community. From frustrating front panel GUI freezes and FT8 automation quirks to critical safety discussions surrounding its internal EFHW transformer, we analyze the collective feedback from early adopters.
Struggling with high noise or limited space on the 40-meter band? This detailed guide explores the construction and theory behind a 762mm magnetic loop antenna, designed to deliver impressive performance from a remarkably small footprint using a unique coupling method.
Unlock the full potential of your Meshtastic nodes by mastering the art of DIY antenna construction. This technical guide explores the critical relationship between resonance and range across the 433, 868, and 915 MHz bands. From calculating precise quarter-wave lengths to building high-gain Slim Jim antennas, you’ll learn how to bypass the limitations of stock “rubber ducky” hardware. Whether you are a beginner looking to understand SWR or a seasoned maker using a NanoVNA for fine-tuning, these practical builds provide the blueprints for superior off-grid communication and maximum packet distance.
This compact 433 MHz Yagi antenna offers solid directional gain, simple construction, and reliable long-range performance. Ideal for amateur radio operators, telemetry systems, and wireless experimentation, it can be built using inexpensive materials while delivering noticeably improved signal strength and reception quality.
Discover how to build the Mini G5RV antenna, a compact multi-band solution for amateur radio operators with limited space. Learn the exact dimensions and assembly steps for this efficient HF antenna.
The Shorty 4020 antenna offers dual-band HF performance in a compact footprint. Designed for 40m and 20m operation, this shortened dipole uses linear loading techniques to fit smaller spaces while maintaining solid on-air results for portable and home amateur radio stations
This amateur radio antenna guide provides technical details for an asymmetrical dipole. By using a 6.75m and 13.5m wire split, operators can access 40m, 20m, 10m, and 6m bands. The design utilizes a specialized Balun and Toroid choke to ensure a clean 50 Ohm match for modern transceivers. Perfect for portable SOTA setups or permanent home stations.
This guide explains the design and operation of a 31-meter double dipole antenna for HF radio. You’ll learn the antenna dimensions, feedline layout, tuning process, and expected performance across the 80 to 10 meter amateur radio bands using simple, practical language.