Re: High Tank Circuit Q

Hi Richard,

On the balanced tank circuit,

> ......You remarked on the notable improvement in your
> test setup when you used the balanced Tesla tank circuit....
> ....This circuit is the highest performance Tesla tank circuit
> I have encountered.....

I didn't mean that I noticed a marked improvement on my balanced set-up vs my unbalanced set-up. 
 What I was talking about was the total capacitance in the system. (I'll get back to this in a 
moment)  As far as my balanced circuit goes, it is the better circuit to run.  I agree, 
wholeheartedly.  The differences I noticed on the balanced circuit is that the sparks are more 
aggressive (forky).  As far as the spark length goes, I noticed about a 10% gain in spark length 
in the balanced circuit.  The tuning is much sharper in my balanced circuit too.  I do expect 
these differences to become more marked when I get the pole transformer set-up complete.

What I had mentioned on the phone was the difference between using .025 uf and .0125 uF in the 
tank circuit, both in an unbalanced configuration.  I noticed the tone of the sound of the spark 
gaps was half the pitch with the .025 uF.  There was also a much lower output in spark.  When I 
talked to you, I attributed this to the charging time constant of the greater capacitance.  In 
short, the tank circuit was being pulsed half as often.  So, the output was much less.  Then I 
later realized what I believe to be the truth.  I had forgotten one very important factor, 
capactance/transformer matching.

It would still be true that the pulsing would be half as many with twice the capacitance.  But, 
with twice the capacitance I should get twice as many Joules per pulse.  The problem is that I 
didn't have enough current available for the greater capacitance. The 15,000 VAC -at- 90 mA is fine 
for .0125 Uf, but it is about half of the current needed for .025 uF, at 15,000 VAC.  I had 
made an oversight on the basics of matching the tranformer to the capacitor.  Don't I feel like 
the fool! :-/

> I am not surprised that Scott was able to hit four foot sparks at
> 1300 watts (neons are remarkably close to their plate ratings in
> output, if the system sucks more RMS juice out of the wall it is
> because it is not power factor corrected) using this circuit with
> two of the Condenser Products capacitors. It just goes to show
> that Scott watched me setting up the 10" coil on the video and
> tried the same experiment scaled down a bit.
> BTW Scott, I didn't know you were getting two of those caps. You
> dog! Having 23 caps to choose from I am all but sure that you
> measured every one and picked yourself out a perfectly matched
> pair! (I would have done the same thing |-)

You're right.  I did start to measure the capacitance of each one to pick a matched pair.  But, 
after measuring 4 units, I found that they were all very close.  It seemed that I could use any 2 
for a matched pair.  Since I didn't really want to unpack each one, I called Condenser Products. 
 They checked their test data, and found all of them are close, within a couple hundred 
picofarads or so of each other.  So I took the first 2 I had unpacked, since my meter said they 
were identical.  They work great in a balanced configuration (obviously).

By the way, I have three of them.  It is a strange story.  Condenser Products called me after I 
received them and wanted me to ship one to another of their customers.  So I did.  After it was 
all said and done, I ended up with a third free one.  Lucky me.  :-)  I may sell it.  I haven't 
decided yet.  Please guys, don't bomabard me with requests for it.  I already have a few people 
that have asked.