DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
The Antenna category collects all of our HF, VHF, and UHF antenna designs in one place — from compact balcony loops to multiband wire antennas and portable verticals. You’ll find step‑by‑step builds for 80 m to 70 cm, including delta loops, trapped dipoles, doublets, magnetic loops, collinears, J‑poles, Moxons, and more, each with practical dimensions and matching options that actually work on the air.
Many designs are optimised for small plots, apartments, and portable operation, with notes on noise behaviour, radiation patterns, SWR results, and tuning tricks. Whether you are chasing DX on 40 m, experimenting on 6 m “magic band,” or improving repeater coverage on 2 m and 70 cm, this section helps you choose and build the right antenna for your station
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.”
Tropospheric ducting is the ultimate “power-up” for VHF/UHF operators, turning line-of-sight signals into long-haul DX. By understanding how temperature inversions and high-pressure systems create atmospheric waveguides, hams can communicate over hundreds of miles with clarity and ease
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
Unlock dual-band performance with the Open Stub J-Pole. This comprehensive guide details how to construct a 2m/70cm antenna using a single feedline. By following precise dimensions for the 146 cm, 48.9 cm, and 15.9 cm rods, hams can build a durable, high-gain vertical dipole perfect for home or field use.
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.
Tired of “RF in the shack”? This detailed guide walks you through building a DIY RF Current Sniffer using LED and Meter indicators to troubleshoot your coax cables.