I understand you did extensive analyses considering the terrain around
you. To what extent did this impact the stack spacing and/or final
73 de Brian/K3KO
Bill Tippett wrote:
> "What happens if the elements are several feet in from the ends?
> Do we still use the boomlength as expressed in wavelengths, or do we use the
> actual length between the elements?"
> Hi Bob et al!
> Boomlength is distance between reflector and the last director.
> SQRT [boomlength] is only an approximation and you should model it exactly
> as others have suggested. My 10M antennas are .791 wl long, WX0B's model
> suggests .889 wl spacing, but EZNEC said 1.007 for maximum gain. If you
> really want to do things right, use YO7 which will let you optimize much
> more rapidly and flexibly than EZNEC. K6STI is still in business and can
> be contacted at email@example.com. I put my KLM's up with stock dimensions since
> I was in a hurry, but later retuned them for ~1 dB more gain, ~8 dB more F/B
> and better bandwidth over 28.0-28.8.
> I believe better RX patterns are more important than small
> in gain, so I optimized with higher weighting to F/B. I also discovered that
> better F/B can be obtained with wider separations. You can see this in YO7
> as you optimize with different stack separations. I verified the F/B using
> another RX antenna ~500' away from the stack.
> Another point...YO7 would allow you to mount the elements at the
> ends of your boom and take full advantage of the boom length you have. It's
> a waste to not use every available inch of boom you have since the wind
> loading, weight, etc are essentially the same. If you have several stacks,
> the cost of YO7 would be well repaid IMHO.
> I'm very happy with my stack now...it holds alltime USA SOSB10 records
> for both CQ WW's, both CQ WPX's, ARRL DX SSB and ARRL 10 CW (missed ARRL DX CW
> by 0.21% last year and it appears I missed it for 2001 also...connector
> during the middle of EU run!)
> 73, Bill W4ZV
> P.S. This is not a paid YO7 commercial...I just happen to be a big fan of it
> because it has worked so well for me!
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