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Re: Arnold Toroidal Ferrite?? Cores

Re Ed Phillip's comments....

>     Will be very interested in hearing the results of measurements
> of transformer voltage waveforms using your (capacitance compensated)
> voltage divider.  Please post results when available, particularly
> if you play with different series inductors.

I have JUST finished the probe and given it some prelim. tests on 
HVDC. All looks perfectly in order. I am not in a position to scope
the transformer/chokes just yet as I don't have a suitable system 
lashed together. However, I will be doing some single-shot primary 
scoping on a small setup this weekend to clear up a mystery concerning
primary behaviour. I am waiting for Scott's capacitors to arrive for 
the neon and choke tests (I need something that will last the 
distance).
    On the subject of long-life capacitors, I finally built the case 
for my polyeth. plate caps and submerged them. The case is clear so
I can see what's going on inside. I noticed two things after two days.
Firstly, air bubbles remain trapped (I now think this must be a prime
cause of failure in the homebuilt caps) and secondly, apart from some
apparent absorption by the plastic of some oil (it has swelled a 
little), there is a cloudy haze that has settled towards the bottom 
of the tank. I am going to haul the cap out and loosen its bonds in
an effort to clear the trapped air (this'll lower its capacitance
but lower is better than none).
    I built this cap as a double unit so that I had 3 values at hand -
two singles, parallel and series with minimal interconnect wiring.
The original nominal capacitance was about 13nF/unit in air.

Malcolm