Scoping the Coil

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

Original poster: "Dave Leddon by way of Terry Fritz <twftesla-at-qwest-dot-net>" <leddon-at-attbi-dot-com>

Coilers,

I would like to measure the tank circuit waveforms on an oscilloscope.  My
scope is not battery powered so any scheme involving a direct connection
through a voltage divider puts the scope at risk.  Several people on the
list suggest the use of an antenna or some form of capacitive coupling to
get a signal into the scope but when I attempt to use these methods, the
noise and trigger jitter completely obscure any detail.  On the other end
of the scope coupling spectrum there's Finn Hammer's sophisticated fiber
optic probe which, while it's ideal, is expensive.

I've noticed on a project at work that signals from a high voltage pulse
generator are coupled into oscilloscopes magnetically using a donut-shaped
device, which I assume is just a coil of wire, encircling one of the high
voltage leads.  Although these pulsers have a much higher frequency content
than a Tesla coil I would think that the principle would still apply and as
long as the coax connecting to the oscilloscope is protected from taking a
direct strike, I think that the scope would be safe.

Is this coupling method worth pursuing?

Dave