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
Ashhar Farhan has officially unveiled the zBitx v2, a significant leap forward for the compact SDR transceiver. With upgraded hardware including a passive FET mixer and a game-changing Wi-Fi-based front-panel connection, the v2 fixes legacy bugs while paving the way for custom user interfaces.
The amateur radio landscape is shifting rapidly with the rise of the “FT” digital modes. While FT8 remains the king of weak signals, the faster FT4 and the experimental FT2 are challenging its dominance. This guide breaks down the technical differences, performance trade-offs, and best use cases for each mode to help you master the HF bands.
FT2 promises to clear a pile-up in the time FT8 takes to finish a single exchange. But speed always costs something — here is what the global ham community has actually discovered after months of real-world use.
The UA4HAZ 20-meter antenna is a clever modification of the classic half-wave dipole, designed specifically for radio amateurs struggling with limited horizontal space. By utilizing a “folded” or inverted-U geometry, this antenna maintains a resonant length for the 14 MHz band while significantly reducing its physical footprint. This guide covers the theory, construction, and proper coaxial feed techniques required to get this efficient radiator on the air.
Height is often the biggest hurdle for Hams, but what if you could trade verticality for horizontal real estate? This detailed guide explores the 21.3m-per-side hexagonal loop—a low-profile powerhouse that offers multi-band performance with minimal visual impact.
Tired of antenna tuners? The T2FD antenna offers incredible wideband performance from 3-30 MHz. This guide breaks down the essential components—from non-inductive resistors to spreader geometry—to help you build a reliable, low-noise “all-bander.”
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.