Have already read N3RR's reply, so will not duplicate his comments.
There appears that there might be a situation in how the antennas were
interconnected. Both antennas need to be in phase. This means that the center
conductor of the coax must be on the same "side" of the drivers in both
antennas. If they are not, the two antennas will be 180 degrees out of phase
the array will show reduced performance whenever it is switched in. Instead of
enhancing either of the upper or lower, the stack will decrease the signal
levels. With a voltage balun, this is not necessarily a simple thing to check.
The easiest thing to do is to switch the feedpoint on one of the antennas,
probably the lower one, if it is more accessible.
You probably already have both feedlines equal lengths, so that should be all
73, Tom, N6BT
Force 12 Antennas and Systems
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