Coil ratio; width versus length.

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

Original poster: "Edwin G. Buttell by way of Terry Fritz <twftesla-at-qwest-dot-net>" <edd.b-at-snet-dot-net>


Edd.B Writes

   I have a question for the list;

   I converted my old tube coil to a spark gap coil
   and the secondary does not conform to the "standard"
   1:4 or 1:5 rule.

   Perhaps some info on the coil will help.

   Primary: inverted cone, 6.25"I.D. by 26"O.D.
   at a 45 deg angle, 16 turns of 3/8" copper tubing.
   Tapped at 3.5 turns in. 

   Secondary: 4.5" dia 43" high, winding length is
   approximately 36.5" using 23ga enamel wire with
   the last several turns spiraling up to a 3"
   porcelain standoff terminal. No toroid is used.
   ( yet )

   NST. 15kv 30ma with 122mfd pf correction. 
   secondary protection, safety gap, choke coils,
   two 250pf caps to gnd (case).  
  
   Spark gap. 7 segment 3/4" copper couplings end
   to end with forced air cooling. A 5" blower at
   3450 rpm forces the air through the couplings.

   Primary cap. Geek caps, .01uf (longest discharge)        
 
   The streamer length is around 20" or so from the
   top of the standoff. The streamers are very steady
   and bright and quite loud.

   Getting back to the question,,, The coil L x W ratio
   is around 1:8.5. Should I cut the coil down to the
   preferred ratio of 1:4 or so ?????????
  
   I think the coil should produce 30" to 36" streamers
   when it finally completed, is that possible with a
   secondary that is too long ?????.

   Thanks for the help.
   73's de Edd.B.