I want to address another twist to the stacking observations, that may
or may not be noticed at all stations. At KN2M, my 15 meter stack is
fully rotatable at 100/50 on a 140 ft tower. By fully rotatable, I
mean the antennas can rotate individually or as a pair for 360 degrees.
The antennas are the traditional B/L/U W2PV configuration. I too notice at
times the higher is better during initial openings, but the whole thing is
further complicated by the location and type of antenna at the receiving
station. At times, quite frankly, my reports into EU vary considerably
depending on the receive antenna. Moreover, I am seeing an advantage with
the stack that I was not seeing last year at this same time of the year.
I believe this is due to atmospheric/ionospheric changes. My conclusion
is that the advantage for stacking AT MY HEIGHTS is further dependent on
time of year/sunspot cycle. This year the stack seems to have more
punch with my reports into EU than last year.
My reports into JA are similar, but the lower antenna is never better.
It is interesting to have stations report that the upper is louder at
their end, when I hear them in NY best with the stack. Moreover,
this pattern has daily variation. Some days in the evening JA opening,
the top is best, other days the stack is the better performer.
By the way, my 140 ft towers are the highest my property and the riggers
can safely support. The environment in Western NY is very close to the
lake. We were just battered with 100 mph winds in my location last
week. The upper antennas can just be reached with our 160 ft rough
terrain crane.
Any other comments on my stacking observation.
73, Dave.
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