Feeding the Double X
There are three basic feeding patterns for the Double X.
For an end fire pattern, the elements are fed across the ridge line.
For a broadside type pattern, the elements are grouped differently, and fed this way
And finally, you can also feed them so you get a 45 degree angle
Obviously, one can mirror or reverse the above schemes to get the rest of the 8 cardinal directions.
How much phase shift?
The phase center of the sloped inverted V is somewhat indeterminate, so doing a phasing calculation based on isotropic point source radiators isn't particularly useful. Instead, a series of simulations were run using NEC2 with current sources on each element and adjusting the phasing.
antenna/dblxfeed.htm - 14 October 2002 - Jim Lux