[TowerTalk] Re: Yagi's

[Bill Tippett]

KB9MZ (via K3BU):

>And it appears that even the most seasoned of amateurs just focus on GAIN,
>F/B and SWR which is really a very unwise and immature aproach.

        I just wanted to give a plug for K6STI's Global Yagi Optimizer
program YO7.  An article about it was in the July CQ (page 30).  There
was an incorrect figure (Fig. 4) which was corrected in a later issue.  

        This is one of the most powerful and easy-to-use programs I've
ever seen to do exactly what Art described.  It will allow you to weight
Gain, F/B, SWR and Zo over any chosen bandwidth.  The program statistically
searches different combinations of element spacings and lengths to optimize
the tradeoff combination you choose.  F/B is optimized for a figure of merit 
based on the backside pattern rather than a single point measurement at 180 
degrees.  YO7 also shows you a graphical plot of the patterns at the low,
middle and high ends of the frequency range you choose.

        Using YO7, I optimized my KLM 610 3-stack for 35' spacing.  Gain
improved by .85 dB, F/B by 7.15 dB, and SWR by 0.2 at the center frequency of
28.4 and improvements were even better at 28.0.  It was well worth the $100
cost and I only wish I had used it before I put the antennas up the first
time!  After using my stack the first season, I felt the F/B was not what it
should be and YO7 told me how to make everything work better.  Brian does
still his software and can be contacted at k6sti@n2.net.  I have no interest
in his software except as a VERY satisfied customer.

                                                73,  Bill  W4ZV


--
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com