Re: Troubleshooting Sequence for Tuning, aka HELP!

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-uswest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi Stan,

Tesla list wrote:

> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<stanmoore-at-mindspring-dot-com>
>
> I am still pursuing the elusive tuned circuit.  I have rebuilt my
secondary to
> replace the one that failed due to internal tracking.  Here is what I have
> found so far:
>
> 1.  According to the calcs, my secondary should be matched to the primary.
> 2. With the toriod removed, I do get fine streamers from the loose primary
> wire.  I had to tap in several turns on the primary to get this.  It would
> appear then my my circuit is wired correctly.

Stan, "the loose primary wire"? I assume you meant secondary wire. Tapping
in on the primary
is correct when top C is lowered (or removed). It appears to be working
properly as far as
connection is concerned.

> 3. With the toriod remounted, the only sparks that I get is when I taped
a nail
> to the toriod.  This breakout point will generate small, fine arcs.  I
can hold
> an insulated metal object close and get a spark length of 8-10".  The
toriod is
> 17" OD with a chord of 4".  Could this be too big?

It is possible that you don't have enough power throughput to cause longer
arcs. Sorry, I
don't remember your transformer data. As long as your getting breakout with
a nail, I'd say
keep the toroid size with the breakout nail in place. I suspect you have
either very low
power into the system or there are extreme losses occuring elsewhere.

> 4. Various tap positions have some effect in length, but not any real
> improvements.

Just find the longest possible arc via tuning, then look elsewhere to
increase performance.

> How would you approach tuning from here?  I am using a SRSG (120bps).  I
don't
> have the phase adjustment capability yet, but I know that will be added
shortly
> to help in the tuning.  Can a grossly mis-phased SG prevent breakout?

Yes, at 120bps, you electrode alignment may be occuring near 60Hz zero
crossing. If you don't
have the capability yet to try something like John Freau's variable phasing
technique, you
can always do it manually. It takes more time and accuracy depends on your
patience. Simply
rotate the disk on the shaft. I'd recommend marking each 5 degree point on
the disk (start
from where you are now) and moving it at 5 degree intervals in one
direction. Once you find
the longest arc setting, you can fine tune further. Obviously there are
easier manual
methods, but mainly wanted to give you a method of attack to getting the
phasing correct. You
shouldn't need to move more than 45 degrees from your current position.

>  Also, I
> am looking at secondary to primary coupling.  The bottom of the secondary
> winding is about 1/2" above the top of the flat primary, and the distance
> between the two is about 3".  Where would folks go from here in the tuning
> process?

3" space between secondary and primary is quite large. This will reduce
mutual inductance
some. You could probably close that gap up to 1.5" with one more inner turn.

> Thanks,
> Stan

Take care,
Bart