In a message dated 7/31/2006 4:19:30 A.M. Greenwich Standard Time,
w7ce@curtiss.net writes:
In my models, I've also noticed that the F/R suffers when the antennas are
stacked. However, I've been able to re-optimize the element lengths based
on the stacking distance and height above ground and can get F/R numbers
that meet or exceed those of a single antenna. In some cases, the change
in
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This is not only the case with SteppIRs, I had the same thing with my KLM
monobanders. However, living in FL, giving up some F/B to get the benefits of
stacking was worth it.
Most of the stacks I had used around .75 for spacing....pretty much what the
master W2PV recommended.
Plans for KH6 include three SteppIRs...the MonstIR at 90, a 4 el at 60, and
another at 30, all phasable with a Stackmatch on Rohn 65.
Over the last 20 years I used Ameritron boxes for switching the
stacks...BIP/BOP/TOP/BOT, and will miss the second one, BOP, since I will be
using the
Stackmatch which has no provision for BOP. Yes, I know I can use the lower
single antennas to achieve that, but I have always been a fan of using all
antennas to get the maximum gain for the higher angle radiation.
Spacing on the antennas for 90/60/30 should be a bit close on 20, but with
the middle one switched out it should be close to the killer stack W2PV spoke
of for 20. The three high should scream on 15 and 10, since I have used stacks
at this height before for those bands.
I'd like to hear from the guys who have used the Stackmatch to phase their
SteppIRs.
Bill K4XS
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