RE: New bipolar

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

Original poster: "john cooper" <tesla-at-tesla-coil-dot-com> 

That is one interesting bi-polar coil.  Did you use glue or ? to secure the 
wire to the form?  Sort of a tiny version of the original Griffith Park 
Observatory TC although the GP coil doesn't terminate into the 'point' 
yours does.  Also, 1/2 of the GP coil was removed (over 40 years ago, maybe 
50) and stored in a shack with the landscaping tools where it decayed and 
was later thrown out as trash.  The retained half was stood upright and 
converted into a 1/4 wave coil.  I've a picture of it taken just prior 
to  being put into storage while the Observatory is being renovated:

http://www.tesla-coil-dot-com/photo_2.htm

It's at the bottom of the page, to the right of the two pics of an ac 
induction motor that might have been constructed by Tesla or his workshop.


---------- Original Message ----------------------------------
From: "Tesla list" <tesla-at-pupman-dot-com>
Date:  Fri, 02 Apr 2004 11:27:50 -0700

 >Original poster: "David Thomson" <dave-at-volantis-dot-org>
 >
 >Hi John,
 >
 >If you really want to build an authentic Nikola Tesla bipolar coil, check
 >out this coil on one of my pages.  The coil itself belonged to Nikola Tesla.
 >
 >http://www.tesla-coil-builder-dot-com/double_cone_bipolar_tesla_coil.htm
 >
 >It is wound on a plywood form.  The plywood form is made by cutting circles
 >of decreasing diameter and stacking them, then turning the whole unit on a
 >lathe.  Each cone is 6" across the base and 6" in height.  The wire is a
 >cotton twill over solid copper wire.  The wire appears to be between 20 and
 >16 gauge.  I'll mic it if you need it.
 >
 >The history of this coil is that an FBI agent passed away and some guy
 >bought it from his estate.  That guy sold it on eBay.  The other bidder I
 >was bidding against (I didn't know it at the time) had the empty forms for
 >this coil already made up.  His father received the form pattern directly
 >from Nikola Tesla.  He was bidding on the coil so he wouldn't have to wind
 >the forms he has.
 >
 >I examined the materials of this coil carefully and they do fit in with
 >early 1900 construction.  I first thought the plywood construction indicated
 >that it was from the 40s or 50s.  Then I found out that plywood was invented
 >over 1000 years ago by the Chinese.  From my experience in dealing with
 >antiques, I could tell the patina on the copper primary was genuine (I had
 >to replace it with new copper because it was kinked in several places - but
 >I still have the original).  The cotton covered secondary wire was Tesla's
 >secondary wire of choice for small coils.  The patina on the end screws and
 >plywood are also genuine.
 >
 >Because this coil was obtained from the estate of an FBI agent, I have
 >wondered whether the FBI agents divvied up some of Tesla's personal effects
 >after they searched his room?  That, in itself, would be an interesting
 >revelation.
 >
 >Oh, yes.  The guy I was bidding against told me the coil is supposed to have
 >antigravity properties.  If it does, they are minute.  I put the coil on a
 >regular household foot scale while running it.  The scale did change
 >slightly when I started the coil, but the change was so slight I chalked it
 >up to electromagnetic force.  The scale I used was made entirely of a
 >ferrous metal.
 >
 >Dave
 >
 > > -----Original Message-----
 > > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > > Sent: Friday, April 02, 2004 3:36 AM
 > > To: tesla-at-pupman-dot-com
 > > Subject: New bipolar
 > >
 > >
 > > Original poster: "John Richardson" <jprich-at-up-dot-net>
 > >
 > > Hi,
 > >
 > > Just would like to run this past anyone who has built a bipolar, and see
 > > what they think.  I've never built one, and am open to advice.  Killing
 > > time until I can run the big TC outside!
 > >
 > > Lately I've been into building small TCs, and would like to keep the guts
 > > for this one in an 8" by 12" enclosure, with the only external item,
 > > excluding primary and secondary, being the gap.
 > >
 > > Secondary:  12 inches of #32 heavy build.
 > > Primary:  1/8" soft Cu tubing, turns to be determined with scrap
 > > wire after
 > > assembled before made permanent.
 > > Cap:  MMC array, out of .15 CD 942s, close as I can get to .0133.
 > > Trans:  The smallest and cutest little 9/30 on the planet.
 > > Gap:  3 or 4 gap tungsten.
 > >
 > > Even though the trans is small, space in my chosen enclosure size will
 > > still be limited, so I plan to run the MMC bank in an equidrive
 > > arrangement.  Are there any inherent disadvantages to this?  And, after I
 > > determine the number of capacitors required, and if that amount is odd
 > > instead of even, can there be an even number on one side and an
 > > odd number
 > > on the other?  I wouldn't think this would matter, but I've learned to
 > > expect the unexpected with these things.
 > >
 > > Lastly, there seems to be limited sites with bipolars, so if anyone has a
 > > link, I would appreciate it.
 > >
 > > Thanks as usual,
 > >
 > > John Richardson
 >
 >
 >