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[Amps] al-1500 parasitic?? or some other problem?

To: <amps@contesting.com>
Subject: [Amps] al-1500 parasitic?? or some other problem?
From: W8JI@contesting.com (Tom Rauch)
Date: Fri, 17 May 2002 21:45:40 -0400
> Well, I can now say for sure that it is not the amp.  I have found
> that by feeding only the top 6 ele 20m beam and pointing it either due
> east or west I can generate the f/2 and 3f/2 products with as little
> as 45 watts.  The beam heading is not what I was expecting as it puts
> both the 40m and 15m towers off the ends of the 20m elements.  The low
> power needed does really narrow it down to something related to that
> top antenna or something very close to it... especially since I can
> not generate them with 1500w to a 4 ele 20m beam 45' below it.
> 
> I can also say that its not the guy wires as the 17 year old rusty
> ones were replaced yesterday.

Hi Dave, 

I'm positive you are wasting time looking for non-linear joints 
producing a F/2 or 3F/2 product. Sub-harmonics are impossible to 
produce by virtue of a non-linear system.
.
Look for a mixing product with another local oscillator or signal of 
some sort, or a spurious oscillation in a device with gain.
 73, Tom W8JI
W8JI@contesting.com 


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