Re: Water HV probe: first pictures

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "B2" <bensonbd@xxxxxxx>

Hi Marco,

May I ask a few more questions to clarify the impression that I am getting 
from your divider web page?

1.   The shiny piece of ribbon coming down from the top toroid is your ground?
2.   How far is the Tesla coil toroid from the (metal ? Ferrous?) wall?
3.   How far is the conducting ceiling (metal? Ferrous?) from the ground 
side (top ?) of your metering toroid?
3.   How is the coaxial cable carrying the measurement signal brought down 
from the upper toroid?
4.   Why did you use a BNC as opposed to an N connector?
5.   What kind of impedance matching termination do you apply between the 
BNC and the measurement coaxial cable?
6.   Why are the voltage divider plates so wide?  (In my experience 1.4" 
(3.5 cm-approx.) worked down to 1 ns.)
7.   Why wouldn"t the capacitance limit the bandwidth?
8.   How do you account for voltage grading along the (apparently?) thin 
edges of the voltage divider plates?
9.   What size (RG = ?) of signal cable do you use?
10.  How long is it?
11.  How do you terminate it at or before the scope, analyzer, etc.?
12.  Do you have access to Frungel, or Chace and Moore, or the Bell System 
technical journals?

B2

----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, December 21, 2004 10:24 AM
Subject: Water HV probe: first pictures


> Original poster: "Denicolai, Marco" <Marco.Denicolai@xxxxxxxxxxx>
>
> Hello all,
>
> Remember all the fuss with the HV probe filled of distilled water? Well,
> now it's built and hanging on the top of Thor. See the first pictures at
> the bottom of the page at:
>
> http://www.iki.fi/dncmrc/work/hv_divider.htm
>
> At the moment we are trying to assess the probe bandwidth by using a 250
> V step response only. It doesn't look good (about 20 us rise time) but I
> have still got a lot of things to try in order to improve it.
> Of course, once again, questions, critics, suggestions and help are
> welcome.
>
> Regards