Re: Spark Gap VI Scope Capture

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

Original poster: "Mark Fergerson by way of Terry Fritz <teslalist-at-qwest-dot-net>" <mfergerson1-at-cox-dot-net>

Tesla list wrote:
>Original poster: "Lau, Gary by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><Gary.Lau-at-hp-dot-com>
>Hi Terry:
>Nice stuff, this is the stuff that fascinates me.
>The negative and diminishing voltage offset that appears on the gap 
>voltage is certainly odd.  One thing that strikes me is that there does 
>not appear to be an identical ground shared between the low side of the 
>gap and the HV probe.  Any difference between the "RF" ground and the 
>scope signal ground would be seen as an offset, although I would have 
>expected it to be more HF in nature.  I know, it's probably not a good 
>idea to connect either side of a spark gap to the low side of a probe, but 
>could this be affecting the reading?  Interesting that the quench 
>coincides with the zero-offset point, but perhaps that's because the 
>difference between the RF and scope grounds disappear then also?

   Just a thought; sparkgaps do have a negative resistance characteristic. 
Could this explain (part of) what you're seeing?

   Mark L. Fergerson