DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
DIY VHF/UHF antenna projects, designs, and build guides for amateur radio and FM communication. Explore loop, collinear, J-pole, bazooka, and dual-band antennas with dimensions, theory, and construction tips to improve gain, bandwidth, and on-air performance.
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
If you could only ever hang one wire in your backyard for the rest of your life, the 94-foot Doublet would likely be it. Often called the “all-bander’s dream,” this specific length is a classic in the Amateur Radio world for a reason: it’s short enough to fit in most yards, yet long enough to be highly efficient on the 80-meter band.
Unlike a standard dipole that’s stuck on one frequency, the Doublet uses balanced ladder line to turn your entire feed system into part of the antenna. In this guide, we’ll look at why the 94-foot length is the “sweet spot” for multiband performance and how to properly interface it with your tuner. Forget complex traps and multiple dipoles—one wire can truly do it all. Let’s get that ladder line hanging!
Learn how to build a high-performance Full-Wave Loop Antenna for VHF and UHF FM radio bands. This DIY guide covers dimensions, polarization, and impedance matching for clear local communication and FM broadcast reception.
The Hotel Antenna is a clever space-saving vertical antenna design popular among VHF and UHF amateur radio operators. It is especially useful for radio amateurs living in apartments, hostels, or temporary locations where installing large outdoor antennas is not practical.
The double bazooka antenna, often described as a coaxial dipole, is a time-tested antenna design widely used by amateur radio operators. Its popularity comes from a combination of simple construction, predictable impedance behavior, and noticeably lower received noise compared to thin wire dipoles.
DIY 300 Ω twin-lead J-pole antenna for the 2 m band offering efficient VHF performance, easy coax feed, and portable installation without radials
Build a simple twin-lead J-pole antenna for VHF/UHF using 300-ohm ribbon cable. This end-fed half-wave vertical with quarter-wave matching stub delivers omnidirectional coverage, low noise, and reliable FM/repeater performance without ground radials
High-gain 435 MHz UHF collinear antenna using three 5/8-wave vertical sections with inductive phasing. Provides ~6 dB omnidirectional gain and low-angle radiation for repeater, base, and long-range 70 cm band operation.
Build a VHF Super J-Pole (collinear J-pole) antenna by stacking two half-wave elements with a phasing stub for ~3 dB gain over a standard J-pole. Omnidirectional, low-angle radiation vertical ideal for 2 m repeaters and long-range VHF communication
Build a 5/4-wave VHF antenna for 145 MHz using 450 Ω ladder line and a choke feed. Shows how to mount, feed, and match this high-gain vertical for FM, repeater, and simplex operations on the 2 m band