Re: mindless question: measuring mot voltage.

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

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

belatedly...


>Some HV probes have a very high resistance and can

>act like an antenna picking up AC voltage even if

>not connected to anything.
         True of any hi z probe, anywhere, any time.

         8)>>
         Most notable in a high field situation, true
         always.
         Demonstration:
                 take any hi z meter (and i have done
                 this with an 'old black moving coil
                 meter').

         Bring near the face of a the TV set (while set
         is on...)

         Note deflection/indication.  May go quite high.
         Further experiment::
                 Experiment with lead placement, etc.
                 (twisting the leads will reduce pickup
                 to minimum/close to zero, etc.)

         Experiment:
                 It may be possible to 'find' the HV
                 (CRT B+) from OUTSIDE the case of the
                 set the same way.
         (I've done it, but with older sets...)

         ANY instrument has 'characteristics' which may
         mean that the indications means something
         different than what they seem to.

         best
         dwp