John, phasing two electrically different driven, shunt fed towers is
not a task for the beginner... It is done by technically experienced
hams (and there are a number on here who can do it in their sleep) and
by broadcast professionals...
However, simply adding a tower 1/8 wave away, loading it to tune~3%
below the operating frequency and having it act as a parasitic
reflector is really quite simple... This is what I recommend you and
your buddy consider... Top hat load the tower and use the inductor
between the top of the tower and the hat as the final adjustment to the
tuning... Use a field strength meter to get the tuning correct...

denny / k8do

John Phillips wrote:
A friend of mine is shunt feeding his 80 foot tower on
75 meters. He asked me if he could install another shorter (35 ft)
inductively loaded vertical 1/4 wave away from the tower
and phase them to favor Europe. I was not sure. Will two unequal
physically, but resonate, vertical antennas have the same low angle of
radiation as two that are equal in size? My thought is that they may
have some kind of directivity, but not as low an angle as equal ones.
Yes, there will be a good system of ground radials.

John / K1BXI