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[AMPS] Shorted Pi-Network Turns

To: <amps@contesting.com>
Subject: [AMPS] Shorted Pi-Network Turns
From: 2@vc.net (measures)
Date: Sun, 10 Sep 2000 11:41:02 -0700
>
>> The progressive shorting of the coil presents problems for the amplifier.
>> In particular, shorted turns will act like a shorted turn of a transformer
>> and can lead to large circulating currents.  
>
>Only in cases where mutual coupling between turns is nearly unity, 
>very high, and/or there is considerable dissipative losses in the 
>system somewhere. 
>
>This is not normally a problem with any air wound inductor, 
>because flux leakage is generally pretty high. It is a problem with 
>toroids, especially if loaded Q is high. 
>
>> May, 1963 issue of 73 magazine by Bert Green, W2LPC.  Bert wrote the
>> article while working for Amperex.  He made distortion measurements of the
>> amplifier after construction and stated that "the distortion was decreased
>> even further by leaving the unused turns on the plate tank coil unshorted
>> when switching from band to band instead of shorting them as was done when
>> the amplifier was first constructed".
>
>Losses and circulating currents don't cause non-linearity or 
>distortion. More than likely he was seeing normal measurement 
>scatter.
>
good point.  73 Magazine has no technical editor.  
>.......

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


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