RE: my mini coil that doesn't work

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-compaq-dot-com>

Hi Robert:

While your secondary is in the mini-class, your 15/30 NST is in the
middle-weight league, so you should be capable of some respectable
streamers.

I can see from your photos that your cap is actually .015uF.  This may
be slightly on the high side for a 15/30 NST.  Mains-resonant would be
about .005uF, and with a static gap, twice that value (.01uF) is what I
would recommend.  But since you already have your cap and it's not
exactly adjustable, it may be easier and cheaper to just add another
15/30 in parallel to beef up the power supply.  Of course, now your 12"
secondary will be the limiting factor on your rig (like having a V-8 on
a go-cart) , but better too long sparks than not long enough!

Regards, Gary Lau
MA, USA



Original poster: "Robert by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<obiwan1186-at-sunflower-dot-com>

I've been working on my mini coil for a while now and i just can't seem 
to get much performance out of it. the best I can do right now is 5" 
arcs to ground with 15/30 input. here are the specs.

primary: 15 degree slanted primary with 9 turns. taps at about 5

secondary: 1.5 by 12 wound with 1000 turns of 30 guage wire. bottom turn

is grounded to bottom turn of the primary. i've tried grounding it to an

RF ground, attaching it to the primary works just as good.

capacitor: .0015 geek mmc bank

gap: tcbor gap cooled with 120 cfm fan hooked up to variac. (the fan 
improves performance a little, but not much.)

topload: small dryer duct bent into a torroid and covered in aluminum
tape.

you can see some pictures at:

http://www.angelfire-dot-com/ks3/tesla1186/minisetup.jpg              -   
picture of the whole set up (it's a really big picture)
http://www.angelfire-dot-com/ks3/tesla1186/miniprim.jpg               -   
primary coil with razor blade tap
http://www.angelfire-dot-com/ks3/tesla1186/minigap.jpg                -   
spark gap
http://www.angelfire-dot-com/ks3/tesla1186/mmc.jpg                    -   
mmc bank
http://www.angelfire-dot-com/ks3/tesla1186/minitoground.jpg        -   arcs 
to ground  (it's also a huge picture)
http://www.angelfire-dot-com/ks3/tesla1186/miniglobe.jpg             -    my

plasma globe setup (another big one)

is there anything i can do to improve performance? thanks a bunch
Robert