DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
Explore Balun and Unun projects on VU3DXR. This tag features DIY guides for building high-performance 49:1 EFHW transformers and 4:1 voltage baluns using T80-6 or FT140-43 toroids. Master essential antenna impedance matching techniques to optimize your portable and home station HF wire antennas.
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.
The GM4JMU shortened dipole uses loading coils to deliver full 40 m band performance in under 10 m span. Ideal compact HF antenna for small gardens, rooftops, and portable ham radio installations.