Re: VTTC

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 8/9/01 10:48:26 PM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes:

> Original poster: "RICHARD HALL by way of Terry Fritz <twftesla-at-qwest-dot-net>" <
> richhallpfs-at-mcleodusa-dot-net>
>  
>  Hello :jcouture and coilers
>  " j" I have been using your JHCTES  3.3  Question do I play the numbers to 
> get
>  a higher coupling num. ie is .227 better than .160 and I know that when I 
> get
>  the pri. to close to the sec. I chance an arc over.  But for vt use is 
this 
> as
>  much of a concern.   2. coil-h/d ratio  I am considering using a 6" sec.
>  because I'll be running about 1kw min. Is their a min coil heith 
considering
>  spark strikes to the pri. etc. I know that I really havent given you much 
to 
> go
>  on but I'll start here. Rich

Rich,

Since tube coils are so "inefficient" compared to spark
gap TC's, the secondary can be much smaller for a given
power input than for a spark gap TC.  For example, I run
my new staccato tube TC on 2400 watts, and I use a
3" x 11 3/4" secondary.  The coil gives 24" sparks.  The
2400 watts is for steady running.  When I switch on the
staccato feature discussed below, the coil then uses less
input power, for the same output spark length.

I used to run the same secondary at 1000 watts, and it
worked fine too, but gave only 15" sparks or so.  If you
make the secondary larger, for instance 6" x 24", the
sparks most likely won't be any longer at 1 to 2kW.

About 10 years ago, when I wanted to make tube coils 
more "efficient", I developed what I called the "sputter mode" 
and also the "staccato mode" of pulsed operation.  These modes
caused the coil to give a pulsed output which reduced the
input power, and also gave the spark and the sound of the
coil a more interesting nature IMO.  I now incorporate the
staccato feature into all my tube coils.  I can vary the pulse
rate to give various effects.

I don't worry much about coupling in my tube coils, I just
use a spacing that looks and works well, and I adjust the
other parameters to give the best output results.  I generally
use couplings between the numbers you mentioned.

Sparks from the output won't strike the primary unless the
secondary is very short.  For example, I once made a 
secondary 7" dia x 9" tall, this gave 34" sparks at 5kW,
but a massive flashover occured from top of secondary to
the priamary, and destroyed the windings.  For a tube coil,
a sharp metal spike should be placed at the top of the
secondary to let the sparks emit from.  The sparks will
go upwards only.

Some of my staccato tube coils can be seen at my website at:

  http:hometown.aol-dot-com/futuret/page3.html

You'll need to click on the tube coil link to see some of the
coils.

John Freau