DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
Most hams think of the G5RV as a giant HF wire, but scaling it down for the 2-meter band creates a surprisingly effective portable antenna. Using a 3lambda/2 center-fed design, this 145 MHz version offers gain and simplicity for your next hilltop excursion.
Living in an HOA or apartment doesn’t mean you can’t get on the 20-meter
band. This stealthy window loop design by PD7MAA provides a low-profile
solution for effective DX without attracting unwanted attention.
This shortened 80 meter dipole antenna offers a practical solution for radio amateurs who lack enough space for a full-size HF antenna. Using carefully positioned loading coils, the design reduces overall antenna length by nearly half while maintaining surprisingly good on-air performance.
This compact open sleeve dipole antenna provides efficient operation on both the 40 and 20 meter amateur radio bands while requiring significantly less space than a traditional full-size dipole. Built from 450-ohm ladder line and fed with RG-58 coaxial cable, it is especially suitable for portable stations and restricted installations.
This compact crystal-controlled DSB transmitter combines a 2N2222 oscillator, diode balanced modulator, and tuned RF output network into a simple yet effective amateur radio design. The circuit is ideal for homebrew experimentation on the HF bands and can be assembled with commonly available components.
The ATS Mini firmware v2.34 now includes experimental support for the LILYGO T-Embed SI4732 receiver. Here is what the hardware does, how ATS Mini firmware works, and what this update means for radio hobbyists
Tired of wasting signal in every direction? This directional Slim Jim antenna design combines the low radiation angle of a traditional Slim Jim with the focused power of a Yagi. Using precise metric measurements, you can build a 2-meter powerhouse that provides high gain and excellent interference rejection for your station.
This shortened EFHW antenna covers 80m through 10m using a 49:1 transformer, 110µH loading coil, and RF choke. Ideal for small spaces and portable HF setups, the design delivers low SWR, easy installation, and reliable multiband performance for amateur radio operators seeking a compact antenna solution.
The VHF slingshot antenna is a compact and efficient design ideal for reliable signal transmission and reception. With a balanced structure and simple coaxial feed, it offers strong performance while remaining easy to build, making it a practical choice for hobbyists and radio enthusiasts working in the VHF frequency range.
Discover how to build a reliable 3-band antenna for 40m, 20m, and 10m. This simplified DL1BU modification uses an asymmetrical dipole and a toroid balun to deliver exceptional SWR performance using standard coaxial cable for your amateur radio station.