[Prev][Next][Index][Thread]

Yet another first coil question



Subject:  Yet another first coil question
  Date:   Wed, 4 Jun 1997 16:55:26, -0500
  From:   RSNV02D-at-prodigy-dot-com ( MATT MCARTHUR)
    To:   Tesla-at-pupman-dot-com


Hello all,

 I have been silently watching this list for a month or 
so now (except when I argued on how caps work) and
I finally finished my first coil.  I am using a 10KV 23mA 
OBIT transformer with a .0061 uF leyden jar cap. My 
primary is 7" in diameter, with a total of 10 turns -at- 
about 6" tall. The secondary is 3.5" PVC with 486 turns
of .025 enameled wire.  My supposive operating 
frequency is around 600KHz. 
  I am running two series gaps made out of brass angle
brackets and carriage bolts. My discharge terminal is 
pretty cheesy, its a large globe 60 watt light bulb covered 
with aluminum foil.
  The only problem I am having is that after I fire it up and 
tune the primary at about 7 - 8 turns (depends on the
spark gap spacing) I only get 6 inch sparks at most.  The 
sparks sre pretty weak too. The bottom of the secondary 
is earth grounded and the discharge was to a spool of chicken 
wire that was also grounded.
  The only thing that I can think of that is wrong is primary 
secondary coupling. The secondary sits almost all the
way down in the primary.  I just read a post that said
something about raising the secondary to about an inch and
a half above the primary to improve coupling.
  Could someone please help me out here!!!???

   Thanks 
      --Matt