Here are a few pros and cons I found while using a four high stack. Would be
interested to hear how this compares with experiences of others using stacks.
In 1991 I did a single 10 in the CQWW SSB test from W0UN. Antennas were a
four high stack (8 el DX Eng. clones 48' booms @ 160/120/80/40 ft.) and
a single 8 el DX Eng at 40 ft. The stack opens the band about 1 to 1.5 hours
before (and closes it that much later) than the single 8 el. Those scatter
EUs we hear beaming the Carribean before the band opens are easily worked
with the stack (even run on CW), this is usually tough from Colorado. I was
able to work VK/ZL after most all the west coast had lost propagation
(reports of "only US signal I can hear"). Really impressive so far but....
Now for the not so good stuff. In the rush to get the stack going by contest
time we ended up with the following configuration. On the stack all four
antennas were always on. We had several phasing arrangements we could use
with the stack, similar to the out-of-phase mentioned in the article about
N2RM. Once the band matured (to EU and JA) the single 8 at 40 feet was
generally 1 to 3 db better than the stack, no matter what the phasing.
Sunday afternoon the opening to JA was very poor and stack seemed about
even with the single 8. One QSO would be louder on the stack the next louder
on the single 8.
So it would seem that the stack with all four antennas going (despite playing
phasing games) has to low an angle to be effective after the opening
matures. That leaves me wondering how much of the time a station like N2RM
(2000 miles closer to EU) can use the upper (or upper 2) antenna(s) when
running EU? Any comments?
73, Jay K0GU jayk@fc.hp.com
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