Re: Experimental Help - Terry?

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

> 
> My experiment involves placing two large shunts in both the primary
> circuits.  I bought two old radio current shunts at a hamfest.  They are
> fortunately stamped on the side as to Amps vs millivolts.  They handle
> hundreds of amps and calculated resistance is milli-ohms and less.  Most
> any shunt if high enough power capacity will work, just keep R very small.
> 

Measuring high RF currents with a shunt is a tricky business because of
skin effect and parasitic L and C.  Pulsed current shunts typically use two
coaxial cages of tubes. The idea is to account for skin effect, mechanical
distortion due to the fairly high forces, etc.  

Since you are going to be looking for very small differences, calibration
and measurement technique is going to be important.  

Think about how to calibrate the setup. Some sort of precision current steps??

> P. S.  Terry, I've well insulated my Pearson CT.  It's bandwidth is 10 MHz
> with a huge amount of amps.  It can be used to measure a lot of other
> "unknown" TC parameters, example, HV current from HVTX to capacitor.
> Actually, one of these low resistance current shunts can also be used here
> before the SG.  I haven't done it yet, but I want to put a very large HV,
> high powered, noninductive, very high ohm resistor (10 - 100 Mega-ohm)
> across the SG itself and measure current and voltage wave forms.  I would
> use the fiber optic probe here and NOT the Pearson.  Then there is NO
> guessing about power loss in the SG.  It can be measured and analysed.
> Lower power loss SGs may be developed.