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Re: High Tank Circuit Q

Hi Mark,

You wrote:

> About balanced tank circuits:  (The Tesla "Equidrive" circuit as some call it)
> I have seen the same small increase in performance from balanced vs. unbalanced
> as Scott demonstrated.  In testing this, you cannot just remove one cap, re-tune
> and re-fire.  This changes the cap value.  You must keep 2 caps in series and
> experiment by moving both to one side of the circuit.

That is exactly as I did, using 2 caps for balanced and unbalanced.  I must comment that while 
the gain is minimal (perhaps 10% as described below) there are other things that are not as 
quantifiable about the balanced circuit that I noted.  It seems to tune sharper and the sparks 
seem more aggressive.  This is something that I can't put down in numbers.  It is my 
recomendation that if you haven't had a chance to run a balanced tank circuit yet, to give it a 
try and see for yourself.  Just don't EVER forget about the stored energy in the caps that must 
be discharged to ground before grabbing the tap on the primary.

> I have measured circuit Q's of balanced vs. unbalanced circuits and have found about a > 10% improvement in Q for the balanced.  I believe that this is strictly due to symmetry.
> Kind of like having a tuning fork with unequal vs. equal length tines.  Intuitively, any
> oscillatory system is going to oscillate better (read longer) if it is balanced in every
> way.  It is up to the individual to decide if 10% more Q is worth the extra cap and the
> extra danger.

I personally now want to run a balanced circuit most of the time.  The extra gains are worth it 
to me.

> Judging by the posts and my own mail, your results have produced a benchmark that others are
> striving for.  Congrats again.

Thank you.  I never thought of it as anything glorious enough to be called a "benchmark".

Scott Myers