Hi J

Many eons ago, almost more than I care to remember, I was using SIX
102 inch whips on my rig. They were actually two sets of three whips
cophased together. Using three whips in a small 3 inch triangular
pattern allowed the whips to be shortened so they would not clip the
occasional low bridge. The purpose of cophasing was obvious, it was
to get more front and rear directional along the roadway.

Whether you use a single whip on each side, twin whips or triple whips
your spacing between the two units must be far enough apart for it to
make any difference. Or, in our case, that big box behind us was like
a shield to radio signals.

FWIW, a 1/4 wave magmount sitting on top of the trailer was often more
effective in and around cities, where a 1/2 wave magmount was more
effective on the road than the cophased whips. That is, until you
crossed under a bridge and wiped them off the trailer.

Unless you can get those whips at least 8 feet apart, it's not really
worth messing with!

TTUL
Gary