Re: Tesla and Measurements.

To: tesla-at-grendel.objinc-dot-com
Subject: Re: Tesla and Measurements.
From: mrbarton-at-ix-dot-netcom-dot-com (Mark Barton)
Date: Tue, 26 Mar 1996 02:30:55 -0800
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Malcolm,

Bravo on a tour de force of an explanation.  It really got me 
re-re-re-thinking the primary thing again.  I realize you have been 
trying to get this across to me for some time now, but I've been on the 
Q.  You are definitely right about the importance of primary impedance 
match to the secondary.  I witnessed the phenomena you mention about 
matching to a certain secondary spark and power input.  While 
experimenting with the FET coil, which was single tuned (no primary 
cap), it was found that the number of primary turns was critically 
important.  Too many and you could not get the power in, too few and 
you blew breakers (or worse).  However, the primary was VERY closely 
coupled.  How much do you think the primary X matters (from an 
impedance matching point of view) when K = .2 or less?

Zap,
Mark

========================================================
>     I think it's probably time to let the cat out of the bag. I have
>now scoped a range of coils from 11uH to >300uH with several different
>capacitors including an extended foil cap and a single static spark
>gap. The scoping was done single-shot. To date and without exception, 
>all operational (read with gap-in-the-circuit) Q's have measured 
>around the 10 mark. I was interested in your measurement of 9.8 and I 
>have yet to hear from anybody who has measured a Q of, say, 12 or 
>greater.
>     SO, bearing this in mind, I asked myself, why would a particular
>coil's performance improve with a large Lp/small Cp combination? Bear
>in mind also that Mark Barton once said on usa-tesla and I will try to
>quote as accurately as possible: "don't just try a capacitor that some
>program calculated for you. Try different combinations of capacitors
>(and by implication Lp) and break rates - there is definitely a PEAK
>(my italics) in performance to be found".
>     I think the word "peak" is the key here. It implies there is 
>some intermediate value of Cp/Lp between the obvious extremes that 
>works best.
>
>     I have two hypotheses :
>
     <very large snip>