[kbmuri]

Looks like your reflector could be out of phase. The Gray-hoverman has it 3.94 inches behind the plane of the active elements. The website you modeled after uses the wide dimension of a 2X4, which I think is around 3.75 inches. I bet someone out there can show us the math, but if I'm looking at your antenna correctly, it looks lke you used a 2x2. If the reflector is too close (or far), it's out of phase, and the reflected signal, instead of augmenting the incoming signal, will interfere with it instead -- do more harm than good. Don't know if this will help your antenna or not, but might be worth looking into.