Coil loudness

Subject:  Coil loudness
  Date:   Sun, 15 Jun 1997 22:15:49 +0000
  From:   davide-at-exit1.i-55-dot-com
    To:   Tesla group <tesla-at-pupman-dot-com>

Out of curiosity, I used my sound level meter to mesure the intensity of
the racket coming from our coil.  While my son ran the coil, I held the
meter and read the level.  At 10 feet ( about as close as I dared get)
the meter read 118 dB - A weighted.  This was while the coil was
operating at  8.9 KVA input.  This is loud!!  You definitely need
hearing protection at that level.  Hopefully, most of you don't get
within 10 feet of an operating coil at this power level anyway.  The
sound level falls off rapidly as distance increases but you need to
protect your hearing.

The coil is operating much better now that the secondary is raised about
3.5 in above the primary.  No more arc overs from the primary to
secondary.  Arc length is at least 7 feet.  It can only be estimated
because the longest arcs seem to go somewhat vertical.  This is with a
small (16X4 in) toroid.  We'll see what a bigger toroid will do.  I shot
some video and took some pictures that I'll try to post in the near

Dave Euans