DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
The HF category brings together all content related to high‑frequency bands, from 160 m through 10 m, with emphasis on practical antennas, propagation, and station hardware. Here you will find compact 40 m verticals, multiband wire antennas, HF QRP transmitters, SDR transceivers, and accessories designed for real‑world home and portable operation. Articles often include measured SWR curves, on‑air reports, and build photos so you can understand how a design will behave before you start cutting wire.
There is a strong focus on getting HF on the air from small Indian plots, apartments, and field locations without sacrificing too much performance. Whether you are preparing for your first HF QSO, improving your 40 m NVIS coverage, or chasing DX on higher bands during good conditions, this section provides tested ideas to upgrade your HF station step by step
Unlock elite DX performance with the Switchable Delta Loop. This detailed guide covers everything from the 141-foot 40m foundation to the ingenious 18-inch tuning tails that enable seamless 30m operation. Perfect for hams seeking a low-angle radiator with a manageable footprint
The Doublet Dipole remains a favorite for hams seeking multiband efficiency without complex hardware. By utilizing balanced feed lines and a 4:1 balun, this antenna design overcomes the limitations of traditional coax-fed dipoles. Our guide breaks down the essential formulas and provides a detailed dimension table for the 80m, 40m, 20m, and 15m amateur radio bands for your next project.
Build a triband delta loop antenna for 80M, 40M & 30M. This trapped delta loop antenna guide covers traps, matching section & construction details
Discover the secrets of the Beverage antenna. We explain how to match 450-ohm impedance to your coax and how to build a termination load that survives accidental 100W transmissions.
Struggling with limited space or high local noise? The Magnetic Loop antenna is the ultimate “stealth” solution for hams. We dive deep into the PA0WIT design, featuring a 1/5 ratio Faraday loop for a perfect 1.1 SWR and peak performance from 7MHz to 18MHz.
The W8JI Super Mini Loop antenna is a compact full-wave loop design that delivers multi-band HF performance. Learn how it works, why it’s efficient, and how to build and optimize it for your stati
The Half Square has been quietly delivering low-angle DX gain to operators who know about it, while remaining invisible to everyone else — including curious neighbours. Shaped like the Greek letter π, it uses two quarter-wave verticals fed in phase through a half-wave horizontal section, matches directly to 50-ohm coax without a tuner, needs no radials, and can beat an Inverted-V by 4 dB toward the horizon. Here is everything you need to build one
On the day Israel and the United States launched their first strikes against Iran, a mysterious shortwave radio station flickered to life on 7910 kHz. It hasn’t gone silent since. Broadcasting streams of numbers in Farsi — a Cold War spy radio technique that was thought to be fading from use — the signal has now been logged from Europe to North America. Radio amateurs have given it a name: V32
It took just one night — February 16, 2026, 22:47 UTC — for a small group of Italian radio amateurs to change the digital HF landscape forever. FT2, developed by Martino Merola IU8LMC of ARI Caserta, compresses a full ham radio QSO to as little as seven seconds, running four times faster than FT8 and twice as fast as FT4. Within two weeks, it had been spotted on PSKReporter from dozens of countries, spawned two incompatible software implementations, and ignited a fierce debate about open-source ethics, automation, and the soul of amateur radio digital operating. This is the complete story of FT2 — the mode, the schism, and what comes next.
If you are running a multiband doublet or any antenna with a tuner, ladder line will outperform coax on almost every band. Here is how to build your own from scratch — four proven designs, common materials, and every practical detail from spacer drilling to routing it through the shack wall.