[TowerTalk] A Question of GAIN

[broz@csn.net (John Brosnahan)]

At 12:13 AM 10/20/98 -0600, Mike Lamb wrote:
>
>Eric:  I just wanted to add a little emphasis to what you said about the
>sound of the stack.  When I first put my system on the air I was
>astounded by the number of people that asked if  I was using a different
>microphone when I made the antenna change tests because the audio was
>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),

When I first started playing with my four-stack of 8L Yagis on 10M 
40/80/120/160ft) and also had a single 8L Yagi on another tower (80ft)
I was astonded at the differences in intelligibility the stack made.

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.

The copiability difference was totally astounding!

John  W0UN


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