Scott-
I have a very similar setup, and have had very similar results.
Mine is XA's at 70/40, and later 80/40 feet, using in-phase feeds.
I have found that the top XA is always 1-2 S-units louder on 20,
for the past 2-3 years. I think the problem is that with these
cruddy sunspot condx, the elevation angles are so low that the
lower antenna just doesn't work very well. You aren't going
to get any benefit from phasing two antennas together unless the
signal strengths from each of them are approximately equal.
When I first put the system together, about 2-3 years ago, I found
the stack to work VERY well on 15, where the lower antenna is capable
of working well, due to it's greater height (in wavelengths ) above
ground.
My advice is to keep it all well maitained, and wait for the spots
to return. It should work VERY well when they return....
As for guys interacting, I've noticed some things in this area
as well. My guys are 27.5 feet long, broken with insulators.
I've found that this length is close enough to a director on
20 that it causes detuning. I determined this by temporarily
removing they guy at the ground (I have 3 sets of guys, so one
set can be removed at a time in good weather for work) and
moving the loose guy in towards the tower. I was able to watch
the SWR change (improve) as I did this. I cured the problem
permanently by adding several big ferrite chokes on the guy
to detune it.
GL!
-Tony, K1KP, fisher@hp-and2.an.hp.com
"The KT-34XA: The Worlds Best Triband Antenna" -K1KP, 2/10/97
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