Re: Floating Scopes

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

Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>

Tesla list wrote:

>Original poster: "Winston Krutsch by way of Terry Fritz 
><twftesla-at-qwest-dot-net>" <u236-at-earthlink-dot-net>

>Hi All,


>I just bought a cute little Tektronix model 321 scope.

>It is rated to only 5 MHz, but that's OK, since it's

>battery powered, and was built before 1963 :-)).  It's

>all solid state, too (not sure if that's good or bad,

>yet).

>Anyway, I was wondering if I could stick this thing on

>the inside

         Depends on the exact meaning of 'inside'.
         If inside the _tubular_ part (must be large?)
         I would think yes.  (cf below)
         If on the inner disk, on top of the coil, in
         the 'hole in the donut', I'd be reluctant.
         (cf below (II))

>of my toroid for making topload current measurements,

>without letting out its smoke.  I'd then view the screen

>from the coil's controls via binoculars

         I:
         One of the 'features' of the Electrum video was
         various people riding INSIDE the top terminal,
         while the machine made 50' or so streamers.
         Electrum has an 8' (??) or so top terminal, cage
         built, so there is room inside and one can see
         out.

         Further:
         Some early van de Graaf machines had equipment inside
         the top terminal (ca 8' dia again): power supplies,
         motor generators for same, etc.  I think some had
         an operator up there, but will not swear to that.

         II:
         Not clear where on or in the 'toroid' the scope
         would ride.  Perhaps temporarily or permanently
         making an upside down half sphere over the top
         of the toroid (mesh of some sort???), with scope
         'inside' THAT.  Downside is that the system would
         need retuning, and the measurements would apply
         to the modified system...  ....and needs work.

>;-)).  My gut says "no", since the scope's components

>use the case as a ground,

         IF the case be a continuous surface (yeah: holes for
         controls, scope) it should be OK.  But its not my
         scope.


>and RF might make things a bit messy.  Comments???

         as above.  This is one of those cases where the
         term 'ground' takes on a very specialized meaning.

>I know I could float it at a high DC potential, but I'm

>not sure about RF.
         Should float nicely.  I would be concerned about its

         becoming a breakout point if on the 'outside' of
         the toroid.  (It is Very Hard to speak unambiguously
         about 'inside' and 'outside' of toroids...  8)>>).
         Simply putting it on the 'top' of the toroid, or
         in the 'hole in the donut' would make me nervous.


-- 
         best
         dwp

...the net of a million lies...
         Vernor Vinge
There are Many Web Sites which Say Many Things.
         -me