[Fwd: Re: Topband: Long Path Direction!]

Ken Brown ken.d.brown at verizon.net
Tue Mar 30 20:24:45 EST 2004



What is the half power beamwidth of the most directive antenna that any 
of you have for receiving on 160 meters? What about the half power 
beamwidth of the most directive rotatable antenna that you have?

You may know which beverage the signal is strongest on, which may tell 
you approximately which direction it is coming from. But then the exact 
directional pattern of your beverage is unknown. Sure, you can predict 
what it ought to be using modeling programs. I haven't read any 
discussion here about having a helicopter with a signal generator flying 
around several miles from your QTH to measure the actual pattern of your 
antenna, so you don't really know for certain what the pattern is.

If you have a rotatable directional antenna, you might be able to 
resolve the direction that the signal is coming from to within perhaps 
several degrees. If you use the null of a loop, that would probably be 
the most precise way to determine the direction, but not on a weak 
signal that you can barely receive. I have also not read about anybody 
here putting the desired signal in the loop's null. Of course we all try 
to get noise sources in the null.

So all this discussion about azimuths of incoming signals expressed in 
the precision I see here is rather silly, isn't it? Sure it is fun to 
speculate about which path a signal followed to get to your receiver. I 
think you may be trying to split hairs just a little too thin though.

DE N6KB






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