Stan said:
All I am saying is that 18 Yagi antennas and the associated switching
to cover 20/15/10 in two fixed directions is a lot of work.
Jorge, two towers with arrays pointing different directions is a good design
for being competitive. As Stan points out, you don't need the near-in
signal rejection operating from CX that we need here in the middle of the
USA. I agree with Stan that 3 antennas on each band in each directions is a
lot more than you need to do well. On the other hand, you're a long ways
from the USA and Europe, so height is definitely important, and stacking
helps accentuate the lower angles of radiation, take out any nulls in the
wrong places, and as Stan also mentioned, give you a proper null in the
right direction (straight up, for instance, which is of little or no value).
If I recall the HC8 station has all the 15s on one tower all pointing
various directions (no stacks to speak of, but stackmaster-type switching so
you can beam more than one direction at a time)(and another tower for 10 and
another tower for 20, etc), and I don't remember any practical problems
caused by this. The paths may have been a little skewed, but that station
obviously makes a huge amount of contacts successfully.
I like the two tower design best, with antennas for each band fixed all in
one direction on each tower, so you have a USA tower and a Europe tower.
When you want to talk in both directions, you split the power at the shack
and send half of it to each tower. If the towers are separated by enough
distance (I can only tell you mine are 174 feet apart), they do not interact
to speak of, even on 40 meters.
73,
Mark, N5OT
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