I use two of these. On 40 they are a 1/4 wave apart and on 80 they are 1/8 apart. On 40 I am feeding them with 84 degree lines and a 71 degree delay line that is switched in. On 80 I am feeding them with  157 degree lines and a 39 degree delay line that is switched in. I use 2 seperate relays to switch the feed lines from 40 to 80 at the base of each vertical and a sperate box to switch the 40 mtr box to the 80 mtr. box. I can go NE<SW and feed them in phase on both bands. It took a lot of planning and work to get this system going. In US dollars it cost me about $750 not including the verticals and the 40 mtr system. Mark W4SVO