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[QUOTE=&quot;tballister, post: 45168, member: 5087&quot;]I did read with interest your description of the stacked Y10-7-13's.&nbsp; Its a respectable piece of empirical work and I appreciate the contribution.&nbsp; Gives me a little pause about my own plans for my modified unit.&nbsp; I've been pondering spatial diversity a lot lately.&nbsp; I never really needed the gain; I needed better directivity and that was the original motivation.&nbsp; However, (I've begun to theorize) multiple units may perhaps have a small advantage.&nbsp; The following is a comment I left at the highdefforum related to UHF receptioin.---------------------------------------------------I've often pondered the notion that where reflections are a significant contributor to quality (or lack of), the 8-Bay designs in general might provide better long term performance. There is a little bit of a concept of spatial diversity involved. A Yagi design, like the 91XG, concentrates energy along a single axis. On the other hand, an N-Bay design aggregates signals received along N different axes. At UHF wavelengths the separations between active elements approaches several wavelengths. It is easily imaginable that if you could independently observe the waveform levels and quality (I, mean &quot;flatness&quot;; absence of serrations), of each contributing element, there is some non-zero probability that at one point in time one element might produce the most optimal signal, while at other times some completely different element would be the better contributor.---------------------------------------------------I'd invite comment on that concept! (Note that it ignores level, focusing instead on flatness).By the way I also appreciated your anecdote about the VSWR meter of your youth!&nbsp; Its that necessity being the mother of invention thing.&nbsp; I've been there!Best Regards,t[/QUOTE]

[QUOTE="tballister, post: 45168, member: 5087"]I did read with interest your description of the stacked Y10-7-13's. Its a respectable piece of empirical work and I appreciate the contribution. Gives me a little pause about my own plans for my modified unit. I've been pondering spatial diversity a lot lately. I never really needed the gain; I needed better directivity and that was the original motivation. However, (I've begun to theorize) multiple units may perhaps have a small advantage. The following is a comment I left at the highdefforum related to UHF receptioin. --------------------------------------------------- I've often pondered the notion that where reflections are a significant contributor to quality (or lack of), the 8-Bay designs in general might provide better long term performance. There is a little bit of a concept of spatial diversity involved. A Yagi design, like the 91XG, concentrates energy along a single axis. On the other hand, an N-Bay design aggregates signals received along N different axes. At UHF wavelengths the separations between active elements approaches several wavelengths. It is easily imaginable that if you could independently observe the waveform levels and quality (I, mean "flatness"; absence of serrations), of each contributing element, there is some non-zero probability that at one point in time one element might produce the most optimal signal, while at other times some completely different element would be the better contributor. --------------------------------------------------- I'd invite comment on that concept! (Note that it ignores level, focusing instead on flatness). By the way I also appreciated your anecdote about the VSWR meter of your youth! Its that necessity being the mother of invention thing. I've been there! Best Regards, t[/QUOTE]

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