[TowerTalk] Modelling a basic stack

Bill Tippett btippett at alum.mit.edu
Sun May 9 22:51:20 EDT 2004


N4CW wrote:
 >I'd appreciate being guided to some good references regarding stacking 
before
I get in too deep :~)

         Bert, I would first use YO7 to optimize the
antennas in their free space stacked configuration.
YO7 already has the A50-5S in the database so it is
simply a matter of selecting it and the stacking
distance you want to try.  YO7 is still available
and is supported by K6STI.  Brian can be reached at
bbACn2.net where AC is the new Morse symbol for @.

         Once you've optimized the F/R, Gain and SWR
performance as a stack, you can then use N6BV's
HFTA program included in ARRL's 20th edition of
the Antenna Handbook to model different stacking
heights over your actual terrain.

         Here is a sample YO7 output showing before
and after results for two stacked KLM 610's:

http://users.vnet.net/btippett/yagi_optimizer_7_0.htm

In my case YO7 gave me ~1 dB more gain, ~8 dB
more F/R and better SWR bandwidth from 28.0-28.8 MHz.

...and here is a sample of what HFTA will show:

http://users.vnet.net/btippett/terrain_&_toa's.htm

         YO7 is a phenomenal program and the best $100
you will ever spend on any Yagi modeling program!

                                 73,  Bill  W4ZV





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