The QDFA is one of the MW receiving antennas designed by Dr. Dallas Lankford. He published many documents (see the Dallas files) where can be found a lot of new interesting ideas for 160 meters.
This is a Quad Delta Flag Array: four in-line triangles (same family of Pennants and Flags) 10.8 m. long and 4.5 m. high for a total length of 107 meters, which I was intended to install 20 cm. above my fence. With correct phasing delays the results appeared amazing with this beautiful lobe, and an RDF of 11.3
Downloadable EZ files:
But, if not installed in the clear, the pattern can be ruined this way:
…..or even totally destroyed like here:
Read more on this PDF file: RXant.PRK_QDFA (1.24 MB)