Phased Delta Loops

[n2ic at bighorn.dr.att.com]

I am considering putting up a pair of phased 80 meter delta loops,
spaced 1/8 wavelength, fed 135 degrees out-of-phase.

In order to get the phasing relationships right, I need to be able to
measure the mutual impedance between the loops.  The ON4UN Low Band
DXing book gives some hints on measuring mutual impedance for vertical
arrays, but it's not clear how to do it for loops, dipoles, etc.   Based upon
some work with MN, it should be a very good antenna, but the impedance varies
greatly based on height and other objects (i.e. supporting towers).  Thus,
I think it is important to measure the Z's, rather than make any assumptions.

Anyone have any suggestions ?

Thanks,
Steve, N2IC/0