[TowerTalk] Antenna Spacing Question

[Williams, Richard (OAG/CPG)]

I have a TH6 right at the top of my tower and a Cushcraft A3WS about 9 feet above that. I have a serious tower and rotator and am going to add a 2 element 40 meter yagi this Fall. Can someone give me an idea of spacing requirements between the three antennas? I have a 20 foot mast, 10 feet of which is currently inside the tower. I plan to move up the rotator shelf. Right now the mast only sticks up 10 feet. It's 1/4 wall Schedule 80. I'd rather not side mount the A3WS lower down the tower as a local suggested. Thanks for any guidance. Rick VE9HF