Bud,
I have a stack of two C51XRs with a C31XR in the middle, effectively giving
me a three-high stack of C31XRs.
I feed each band with a separate feed line. Consequently there are 11 feed
lines going up the tower to the three antenna. I also employ three-port
StackMatch on 10, 15, 20 & a two-port StackMatch on 40.
Stack spacing is 33'.
Top at 118'
Middle at 85'
Lower at 52'
I spent a great deal of time studying the installation heights and stacking
distance. As has been pointed out, the multi-monoband (single boom)
antennas do introduce some compromise in stacking performance because the
distances change with frequency. I designed for max performance on 20, then
40, and had to somewhat accept what happened on 10 and 15, which is still
great.
My HFTA terrain files and much more data is available on my website:
www.W5WZ.com
73,
Scott, W5WZ
Secretary/Treasurer, Louisiana Contest Club
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|