An own-design 6 element Yagi on a 5.7m boom. This antenna was specially designed to have exceptionally low side lobes (a very clean pattern) and very high f/b in an array. Even though we live in a country location 15km from the nearest town, there is QRN from power lines 3km away. An antenna with high f/b definitely reduces QRN and helps RX performance (confirmed by the 6m EME signals received).
Here is the computer simulation of the Yagi:
The Yagi's feedpoint impedance is 28 ohms which is matched by a 1/4 WL coax transformer and balun (a modified "DK7ZB match"). Special effort was made to get the physical antenna to replicate the computer design with a boom compensation factor determined for the particular mounting insulators used, and cutting the element dimensions within 1mm. The actual SWR curve followed the computer model almost exactly, and was essentially flat at 1:1 SWR from 50 to 50.3 MHz.
This 6m antenna was used here from June 2014 until Dec 2014.
The intention was to build an array of 4 of these Yagis, but that was abandoned after discovering the difference in wind loading between a 4-bay array of short Yagis with it's associated H-frame, and a 2-stack of longer Yagis on a rotating mast. We live on an exposed hill top, so wind survival is an important factor.