assuming they are being fed in phase and are polarized the same way they
should work best at an odd multiple of 1/2 wave apart... measured boom to
boom. of course at 70cm a 1/2 wave spacing is only 35cm, which is pretty
close and will probably result in unwanted interaction between them. i
would go for at least 3/2 or 5/2 wave spacing... 3/2 spacing is only about
1m which is very workable even in a small space and would be reasonable for
fairly short quads. if they are long ones you may want to go for 5/2 or
even wider spacing. one kind of generic rule of thumb is that you want them
at least as far apart as their boom length..

one other thing, this is not an odd application. it is fairly common to see
horizontal stacking of yagis for vhf and uhf. cushcraft used to sell a pair
of 2m yagis with a cross member and phasing line. many big gun uhf stations
will stack 4x70cm yagis in a square with an H shaped framework.


"ab5mm" wrote in message
...
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