The 7 mhz band has always interested me mostly due to it's consistent propagation characteristics. You can usually find 40 meters open to some place in the country or world. It's where I enjoy experimenting with antennas the most. Antennas for 40M are or managable size and anyone can get something to radiate from even the smallest piece of real estate.
The Double Delta Loop Array was 2012 experiment. It was a solid performer especially for stations down under. I kept almost daily skeds with my long time friends VK3RP and ZL1BVB. The antenna also has a lobe to Europe and made many contacts with my good friends CT1ZQ , EI6AK, F6ACD.