[TowerTalk] Need help ref. spacing elements, 2 el 20 m wire beam

[Steve Davis -Davis RF Co.]

 Hi,  I'd like to put one up, fixed on KH6M  (Midway)  DX pedition. 
Wondering what anybody suggests for best possible signal to them, short 
haul,  from East coast, as far as reflector length and
spacing to driven element ?  I will have the ant. at 33 ft.
  Driven element will be 1/2 wave , imped. adjusted to 50 ohm.
  Tnx a lot,  Steve  K1PEK