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[AMPS] Re: Choke Isolation Using Coax Cable

To: <amps@contesting.com>
Subject: [AMPS] Re: Choke Isolation Using Coax Cable
From: 2@vc.net (measures)
Date: Mon, 8 Jan 2001 10:26:24 -0800
>Rich Said:
>
>You prefer to use a core that can saturate?.
>
>Fred Says:
>
>I don't have or ever will have a ferrite toroid core saturation problem 
>because Amidon specifies the ones to use and also states what happens well 
>before saturation can ever occur. You might like to get their more detailed 
>publication that specifies and provides salient characteristics of their 
>products. 

I have saturated ferrite cores.  

>The air  core "ugly balun" is saturation proof.  

>Mine is dated 1996 so there is probably a more current one 
>available. They have no title to the book (8 x 11 size) so you have to ask 
>for the detailed manual.
>
I have the book provided by the ferrite manufacturer.  
>Rich says:
>
>This tuner was not intended for QRPP.  Not saturating with large suds was
>an important issue for the balun.
>
>Fred Says:
>
>Understood. I am not referring to a QRPP area.  I am only referring to the 
>ferrite core issue.
>
power counts.  SWR counts.  

>Also, I mentioned the problem where an L-Matching network can not match all 
>impedances . Nevertheless, a fairly wide load impedance range is covered by 
>swapping input and output of the L-network -- 

good point.  This is why I used a 2-position switch.  

>but there are load impedances 
>that can not be matched as I previously stated (included the fact that it 
>takes eight L-network configurations to match all load impedances --

either the shunt C is across the input, or it is across the output.  I 
count 2.  

> I have 
>proved that to myself and Phillip Smith, like I said before, also has). 
>But, like the old EF Johnson Matchbox which many are still using, an 
>external shunt or series reactive component can easily be added to allow a 
>conjugate impedance match.
>
If a conjugate match were provided, amplifier efficiency would be no more 
than 50%.  
>Rich says:
>
>A saturation-proof, low-cost, non-resonant, non-incendiary balun is a
>"poor solution" ?
>
>Fred says:
>
>Again, they are not balun ferrite cores as you describe.  The correct 
>choice of a ferrite balun toroid core, will prevent those problems 
>concerning saturation from occurring.
>
>Rich says:
>
>I deliberately did not answer that question because I smelt red herring.
>
>Fred Says:
>
>I don't understand the "smelling of a red herring" statement? Am merely 
>curious regarding what you use to measure the balun and toroid ferrite core 
>characteristics? 

I did not measure the ferrite core balun./see below.    

>Also, how did you determine that the configuration you 
>chose will match all load impedances?
>
>Have you experienced any ferrite core saturation problems and/or failures?
>
I experienced  Feculent TVI at 555MHz.  

-  Rich..., 805.386.3734, www.vcnet.com/measures.  
end


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