Hi group... Need some input.

I need to stack two 432mhz quads, not in the traditional vertical plane,
but horizontal. This brings me to two questions... (1) What distance
apart? 1/2 wave length or 1 wave length or ?? (2) Do I need to make
that measurement from boom center line to boom center line OR would it
be end of element to end of element?

Thanks & 73,

Steve
ab5mm