>
>> 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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