130kW Coil Visit (fwd)

Date: Wed, 28 Jan 1998 02:42:50 -0800
From: Terry Leonard <terry-at-cruzio-dot-com>
To: chip-at-pupman-dot-com
Subject: 130kW Coil Visit

I30kW Coil Visit:
    I want to share with the group some of my experiences and
observation while visiting Greg Leyh's 130KW coil.  First off, I have a
limited knowledge of Tesla coils and  the last one I built was in 1970.
It used a  NST & window glass capacitor, not at all in a league with
Greg's work.   Greg's 130kW coil, as some of you already know, is
located at Hunters Point in South San Francisco in an old Navy
shipyard.  It is a good location away from the residential areas of San
Francisco.  The ship yard, except for the nearby Railroad Museum,
doesn't appear very active.   The facility has  gates with guards that
can sometimes be annoying  with their rules and regulation.  Each visit
is different as the guards sometimes want to see  ID, vehicle
registration, and proof of vehicle insurance.  On occasion a pass is
filled out and  must be placed under the windshield but at other times
no pass is filled out.   In any case expect the unexpected.  Once while
I was waiting at the guard shack for Greg, to escort me, an angry person
drove up at started yelling at the guards. The angry person left and
about twenty minutes later the guards showed up at the "coil" and wanted
to talk with me.  They asked me to sign a statement as to what I saw
happen with the angry person, very weird!   At other times while at the
coil the guards/police will  drive by at  night at high speed as if
chasing someone, again strange!  Maybe they get bored.  Back to the
       On first approach, the coil can easily be seen  against the
buildings and shipyard equipment as it stands about two and a half to
three stories tall!  It sits in a fenced parking lot and nearby is
another of Greg's monster coils covered with tarps in storage.  The
spare coil has come in handy and was cannibalized for copper bussing and
a pulse capacitor.
The new coil structure is supported on top of a plywood room or "vault"
which is reinforced with metal  supports to carry the weight of the
secondary  and spherical  top electrode.  The top electrode  appears to
be approximately  6-7 feet in diameter and is made of metal hand railing
circular rings welded in a net or web fashion to form a spherical
shape.  The outside surface of the rings are smooth.  The coil is made
for outdoor exposure and I believe it is covered  in fiberglass.  The
vault was recently reinforced with additional steel beams because of
rotor balancing/vibration problems.
The additional steel beams outside were bolted through the vault walls
to the interior rotor structure for added stiffness.  I believe the
rotary gap balancing is close to completion if not already  done.  Is
that correct Greg?
       The primary of this coil is located inside the secondary coil!  I
would guess that the secondary is 2 and a half to 3 feet in diameter and
the primary fits inside it  and can be adjusted up or down to change
coupling .   The coil has a rope ladder hanging inside the secondary for
passage up through secondary and primary to the top electrode.  What a
thrill it was to climb the rope ladder inside the secondary, can you
imagine climbing inside the secondary!  Wow! The transmission lines,
large diameter copper pipe maybe 3 inches in diameter, connect to the
rotary gap and capacitors.  The lines connect to the primary and the
tubing fits together in a "trombone" fashion which allows, when clamps
are loosened, for the primary assembly to slide up and down for tuning.
Three of us working with the help of a jack and long 2 x 4  managed,
with some difficulty , to slide the primary up and down for tuning
(coupling).  Adjustment results, at this time, were observe  during
single shot pulse operation on an oscilloscope.   I will continue at a
later time with more about the single shot mode of operation.
    Oh! I forgot to tell you this coil is power by DC (direct current)
in the primary/gap/ capacitor circuit.
      Images of this coil can be seen at Chips web site  www.pupman-dot-com
.If you haven't seen pictures of this 130kW coil you must check it
out.   From Chips site scroll in the left frame for Photos then click
on "The latest  images from list".  Then scroll down in the main frame
box and click on "Images of Greg Leyh's monster coil".   As I understand
it the new secondary, for the final 130kW, is used as the secondary in
all photos.  The final version of the secondary is fiberglass covered
and is shown in the photo where R. Burgert is having lunch in the top
electrode.   The great photos of "Sparky" taking arcs to the head were
done before the fiberglass was applied to the secondary.  Also all the
arc photos are done at a lower power setting because the primary
circuitry is not that which will be in the 130kW version.   The 130kW
version has not yet fired in continuous mode but has been fired in a
limited pulse or single shot mode.  Greg please gives us some feedback
on any errors I might have made in posting about your coil.   Also I'm
sure the group would like to here any other comments you might care to
make.  Good night to all.  This is my first post to the group.   Thanks
to all for the enjoyment I receive from your postings.
    Terry Leonard

* * * * * * * * * * * * * * * * * * * * * * * * * * *
Always remember you are unique, like everybody else!
Terry Leonard <terry-at-cruzio-dot-com>
* * * * * * * * * * * * * * * * * * * * * * * * * * *