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Re: well, this is interesting

Subject:  Re: well, this is interesting
  Date:   Tue, 6 May 1997 00:53:16 -0400 (EDT)
  From:   richard hull <rhull-at-richmond.infi-dot-net>
    To:   Tesla List <tesla-at-pupman-dot-com>


At 12:10 AM 5/4/97 -0500, you wrote:
>Subject:  well, this is interesting
>  Date:   Sat, 3 May 97 05:02:48 UT
>  From:   "William Noble" <William_B_Noble-at-MSN.COM>
>    To:  "Tesla List" <tesla-at-poodle.pupman-dot-com>
>
>
>well, I learned a few things tonite - maybe even some make sense.  I
>added 
>some capacitance to my new coil - I started from .001 mica and added a
>.001 
>14.5KV capacitor made by Plastic Capacitor company (it's about 1"
>diameter, 8 
>inches long, encased in glass) - sparks went from dinky little 3 inch
>sparks 
>to really nice looking 18 inch sparks with lots of forking.  So, adding 
>capacitance is good, and the little Plastic Capacitor unit is good too -
>it 
>warmed up just a bit in a 20 to 30 sec run (about as long as I can run
>with my 
>half done RQ spark gap with no fan) - it felt like it raised up about 5 
>degrees or so.
>
>I also learned that the toilet float I used for a top capacitor (a
>plastic one 
>with some aluminum foil wrapped around it) keeps a charge - I got a
>small 
>shock when I went to dismantle the coil - I don't quite understand this
>since 
>I thought it would be grounded through the secondary (the low side of
>which is 
>grounded), but the connections were't the best, so maybe there was an
>open 
>circuit???
>
>What I don't understand is the following - when I doubled the tank 
>capacitance, I would have thought I would halve the tank inductance to
>keep LC 
>about constant and maintain resonance with the secondary.  But I found
>that 
>with .002 uf it was best on turn 13 (I only have 14 total turns on a 1/4
>inch 
>{50 ft} tubing flat spiral primary), and with just the .001 mica
>capacitor it 
>seemed to like fewer turns - my notes say that with the same secondary 
>configuration (toilet float on top, etc) I got best performace at turn
>8, and 
>with no top capacitance, best was at turn 13.  does this make any
>sense???
>
>And, can I expect still better performance by adding more primary 
>capacitance?? (input xformer is 15KV 30 ma neon) - it would seem so....
>
>

William,

18 inches out of .002ufd!!??  Good goin' guy!  Nice touch the thirteen
turn
primary.  (warms my heart).  I think you finally hit tune on the
.002ufd.
The earlier tune (.001) was probably a harmonic. The second tune with
the
.002 was real.

The inductance on a primary soars with each turn out at turn 13!  It
isn't
linear turn for turn, so one can't expect16 turns to be twice the
inductance
of 8 turns it could be 4 times as much, or even ten times as much
depending
on a number of factors.

With your transformer, about .005ufd would be a good limiting point
before
needing more ammo at the head end.  Watch those glass caps carefully,
but
watch them with safety glasses on.

Richard Hull, TCBOR