Topband: VERTICAL SPACING

[Mr. and Mrs. Magoo]

A friend up north is attempting to install a pair of phased 60 ft verticals, 
top-loaded for 160M using wires dropped from fairly tall trees.  He can't 
get the needed 134 ft spacing...the trees went on strike and won't move! 
The best he can do is about 128-130 ft.

What effect will this have?  I suggested that it probably would not make a 
lot of difference in the forward gain but might change the shape of the 
forward lobe and also the F/B somewhat, but what do I know!  Can someone 
enlighten us here?  Best he discover these things before he starts 
climbing!!

Bill, VE3CSK