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Re: Double humpin'



On Tue, 5 Nov 1996, Tesla List wrote:

> All,
> 
> I get the impression that some of our folks think that you get a double 
> hump or spliting of frequencies at tight coupling.  Double humping only 
> occurs in spark systems when we exceed the point known as "critical 
> coupling".  critical coupling has only a little to do with 
> actual inductive coupling (about 50%)
> 
> If we throw a fixed gap of a fixed dwell/quench in a system, critcal 
> coupling occurs at some fixed coupling coefficient K=X.  If we have a 
> variable dwell/quench gap, and a fixed tight coupling, by varying the 
> dwell we can make the system go from  below critical coupling to well 
> beyond.  In short, critical coupling is a sliding point based on actual 
> inductive coupling and dwell/quench time of the gap's realizable 
> quenching ability.  In theory we can have a single frequency output (no 
> splitting) at k=.65.  This was the struggle in the early days of spark 
> transmitters in the 100KW-.5MW class.

It was my impression that the "double humping" occurring at critical
coupling was dependent on the Q's of the coupled circuits.  Certainly the
gap affects the Q of the primary, but I thought that the shorter quench
times were more effective in allowing you to use higher couplings and
still get the gap out of the way before the energy started transferring
back to the primary circuit, rather than using the gap to actively
modify the point of critical coupling (or is this a matter of semantics
biting me in the a** again?).

Steve Roys, TCBOM.