Topband: Dual band array

[MERVW2OE@aol.com]

Roger, my models, as well as some experience, agree with your statements 
about increased spacing or phase angle.  However, what I m seeing is that if 
you go too far you pick up some pretty big side lobes.  phase angles of -100, 
and -200 seem to be optimum, but beyond this you pick up some pretty good 
lobes at about 135 degrees.  Similarly, a spacing of 70 feet on a side 
(approximately 100 foot diagonal)  seems optimal, but again if you go beyond 
this you pick up the same side lobes.  

My radiators are wires pulled up into trees with a diagonal of 90 feet.  
There was no easy way to move the trees so I pulled the base of each vertical 
back about 5 feet, giving me a diagonal of 100 feet at the bottom, but with 
each vertical sloping in at the top so that the diagonal at the top is still 
90 feet.  Models indicate a 5 db improvement on front to back and a marginal 
gain improvement - almost as good as increasing the spacing overall.  I set 
my system up this way the beginning of this season and while I cant quantify 
it I feel there is an improvement.  

No ideas on making it work on 160, but would love to if you come up with 
something.

Regards, Merv  


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