[TowerTalk] stacking different antennas

[Michael Keane K1MK]

At 09:20 PM 3/9/07, Cqtestk4xs at aol.com wrote:
>I know there may be a phasing difference, but I will be running 
>identical  lengths of
>coax to them, so I'm not sure where the phasing difference that guys  mention
>in this stacking comes from.

No, that's not it. The phasing concern with stacking dissimilar 
antennas is that the "zero phase" point the antennas will be in 
different positions horizontally. That requires an additional section 
of "delay line" be inserted into the feed path to one or the other 
antenna to bring them into phase.

The phase difference can be modeled or it can empirically determined 
(see:  <http://www.arraysolutions.com/Products/dissimilarants.htm>).

73,
Mike K1MK

Michael Keane K1MK
k1mk at alum.mit.edu