[TowerTalk] Stacking tribanders (SteppIRs)

[Cqtestk4xs at aol.com]

In a message dated 7/31/2006 4:19:30 A.M. Greenwich Standard Time,  
w7ce at 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