With a 2x6,5m dipole it is not optimal on 80m. But if we double the length to 2x13m makes a lot of difference. I tried this on a field day and it worked very well on 80m with good reports. Also tried the two baluns and both gave the same result as the short one. If you have the possibility to hang out 2x13m you have a great multiband antenna to work on 10-80m and its home made.
Download Multibad 1 and 2 as pdf: Multiband1&2.pdf