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 RA9SUS simple loop is a compact HF antenna covering 14–30 MHz using a 4.7 m rectangular loop and variable capacitor tuning. Ideal for balconies and small spaces, it enables efficient multiband operation without large wire antennas or ground systems
Full-size Delta Loops for the 40-meter band normally require around 42 meters of wire—often impossible for operators with limited space. To overcome this challenge, Andy (2E1TAP) documented his attempt at constructing a space-efficient, shortened 40-meter Delta Loop.
Compact 4 m shortened vertical antenna for the 80 m band using a 64 µH loading coil and LC base matching network. UR0GT design enables efficient 3.65 MHz operation in small spaces with full-size radial system for strong HF performance.
The broadband butterfly (bi-square) antenna uses two connected square loops to deliver stable 50–75 Ω impedance, low noise, and several dB gain over a dipole across VHF/UHF bands. Simple bidirectional design requires no tuning and scales easily for 144 MHz and 430 MHz operation
Common-mode currents are a well-known enemy of clean RF communication. When RF travels along the outside of your coaxial cable, it causes feedline radiation, noise pickup, RFI in the shack, audio distortion, and unpredictable SWR variations. To solve this, radio amateurs typically install a CMC choke (also called a current balun or common-mode filter) at […]
The dual-band 144/430 MHz Square Loop Antenna is one of the most efficient and compact VHF/UHF antennas that amateur radio operators can build at home. Designed to cover both the 2-meter and 70-centimeter bands, this antenna offers excellent gain, low noise reception, and impressive SWR when constructed correctly.
Ditch the lossy traps and discover the Morgain Antenna—a clever, compact dual-band dipole for 40m and 80m. Operating at just 20 meters long, this wire-only design uses folded elements to achieve resonance without bulky coils. The ultimate space-saving solution for your HF station
Limited on space but want to get on 40m? Learn how to build a high-performance, reduced-size 40m antenna using high-Q loading coils. This guide covers calculations, coil winding, and tuning techniques to fit a 20-meter band antenna into a compact 10-meter footprint.
Low on space but want to reach the 80m band? This technical guide walks you through building a shortened Inverted V antenna for 3.700 MHz. Using high-inductance loading coils, you can fit a full 80m radiator into a restricted urban footprint while maintaining a low SWR
Build the legendary G5RV multiband antenna with this comprehensive DIY guide. Discover the technical balance between the 102ft radiator and the critical matching section that allows for 80m–10m operation. Learn how to optimize your feedline and avoid common RFI “growing pains”