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[Amps] Non-linear subharmonics was: Nonsense, AL-1500 parasitic

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Subject: [Amps] Non-linear subharmonics was: Nonsense, AL-1500 parasitic
From: W8JI@contesting.com (Tom Rauch)
Date: Wed, 22 May 2002 00:09:01 -0400
> I still think something in the amp or something in the
> feedline/antenna/tower/guy system can cause the problem.  In response
> to the initial question, I asked about ferrites in the tank.  But
> maybe a solid state driver could produce the sub-harmonic. If the
> measurements are correct, then the spurious is truely a sub-harmonic
> and it becomes interesting to find the source. 

It is especially interesting now that Dave says he duplicated the 
problem with diodes.

I have never been able to generate a submultiple of a signal with an 
form of non-linear system, including saturated ferrites. 

I wish it were that simple.
> from one > cycle to the next to be lower in frequency. To be an odd
> fraction of the > fundamental would mean that the non-linearity
> effects one cycle of the rf > fundamental but not the next!

That is correct. Dividing frequency requires more than a simple non-
linear junction, or a non-linear device like saturated ferrites.  

Whatever it is it requires that one point in one cycle is *not* 
treated like the next repeating point. That's why you never find 
subharmonics generated in solid state or tube-type PA's, ferrites, or 
conventional diodes. 73, Tom W8JI
W8JI@contesting.com 


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