Hmmm.... "hot spots" .... Sounds like grade 9 physics :)
Perhaps the correct utterance is that the windings gaps provide a
redistribution
of the inter-thread capacitance that can and will form an resonant circuit
:)
In other, simpler, words, the gaps prevent the accumulation of capacitance
and/or inductance
for a specific frequency. Common occurrence with LONG and NARROW coils :)
The same effect can be achieved by having a coil that allows for some
spacing (at least
one diameter of the wire) between all threads, but this makes it to long
for a practical application.
Alex
> -----Original Message-----
> From: amps-admin@contesting.com [mailto:amps-admin@contesting.com]On
> Behalf Of Tom Rauch
> Sent: Sunday, June 30, 2002 8:51 PM
> To: 'Amps'; Phil Clements
> Subject: Re: [Amps] choke resonances
>
>
> > Please inform us, Tom, if you his name, the person who
> > wound up one of these things for the first time. I would like
> > to ask him his reasoning for making gaps in the winding.
> >
>
> Someday when I have time I will put some amplifier stuff up on my web
> page, and testing chokes should be one of the more useful things.
>
> The gaps are there because those areas were "hot spots" where
> voltages were highest when series resonances were checked. Removing
> turns from the voltage hot spots has by far the largest effect on the
> series resonance frequency compared to changes on other frequencies.
>
> With that in mind, if you want to move a series resonance don't just
> peel turns off on the end, remove turns at the area of voltage peak.
> Doing so will let you move the series resonance up much more rapidly,
> because you are removing both inductance and capacitance from the
> critical area.
>
> 73, Tom W8JI
> W8JI@contesting.com
>
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