[CQ-Contest] Stacking of two towers -any experiences?

[Jim Brown]

The phase relationship between the radiation of two antennas, and thus 
their combined directivity, is determined by ALL OF these factors -- the 
design of the antennas, the precise operating frequency, their relative 
positions in space, their orientation, the position of the listener, the 
interaction of their respective wavefronts with the earth, the ratio of 
power fed to each, and the phase shift that results from the electrical 
length of their feedlines.

The most effective and predictable stacking performance depends on the 
two antennas being in vertical or horizontal alignment, using identical 
antennas, and having electrically equal lengths of feedline. That is, in 
vertical alignment on the same tower for control of vertical angle, or 
in horizontal alignment for narrowing the polar pattern. Anything 
different from that is wildly unpredictable, and likely to be much less 
useful.

73, Jim K9YC

On 11/12/2024 10:42 AM, SM0HRP Kari Gustafsson wrote:
> Winter is approaching and I did not make it in time for a vertical stack.
> 
> I have two towers with a JK2015 (5 el on 15 and 20 meters) and JKmidtri (4
> el on 15,20 and 10 meters ) respectively on each tower. I have a Stackmatch
> II for 20 meters and a StackMatch II Plus for 15 meters prior HP BP filters.
> Then I use the PB2 and PB3 Hamation controllers to steer the phasing and
> combinations (1,21+2 or 1-2).