Hi John,
This is all explained in my most recent reply to Eric written yesterday.
> >NOTICEABLY better with the stack. I can only surmise that there is less
> >selective fading and resultant distortion. In busting piles it is also
> >apparent because because of propagation often I am getting through on
the
> >first call but getting no better report than the next guy in line.
> >
> >73/Mike, N7ML
>
> Mike (and Eric),
> I started working Asiatic Russians that were S9 on the single 8L and were
> a bit stronger on the stack, but they were totally unreadible on the
single
> 8L (on ssb) due to "selective fading" but were without any sign of
distortion
> on the stack.
>
> That is when I made the conclusion that the distortion was just that of
> multipath rather than some sort of "polar flutter". The stack, with its
> clean
> pattern which had no significant high angle lobes only received one path.
> The single 8L had higher angle lobes and was receiving two (or more)
paths
> with different time delays--causing the "selective" fading.
Thanks for the input. It validates an effect I have long noticed on 160 and
80 meters, and something commercial texts have mentioned for years.
It isn't the fact the antenna has "spatial diversity", it is the fact the
antenna is better focused that reduces fading. Diversity ONLY works with a
intelligent voting system, and that requires dual receiving systems from
antenna to signal output.
Transmitting or receiving sky wave signals with "dual polarity"
antennas...contrary to some antenna advertisements...always increases
multipath and fading.
73 Tom
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