Re: Current XFMR

> The best CT for 60 hz use is an iron core version.  These can be had 
> for as little as $30.00 new.  

Here's a tip from another satisifed low-budget hamfest scavenger - if 
you have any hamfests near you, GO - there's no telling what you'll 
find.  CT's for 60Hz can be found in the $2 to $5 range and although I 
didn't see any this weekend, I did buy a Tek 556 dual BEAM (not trace) 
50mHz scope in decent working condition w/one 1A1 dual-trace plug-in, 
probes, and the manual for $40.  If I can find another 1A1 plug-in, I can 
use this as a four trace scope.  Alternatively, are any of the other 
plug-ins useful for TC work - like differential input, frequency sampling, 
etc... and does anyone have any of these (or a 1A1) for sale?

> The Rogowski coil is better for 1000 amp 
> currents and above of short pulse duration  An op amp integrator is 
> necessary to get a wide and linear bandwidth.  Mine is used in the 
> 20,000 amp range for pulse discharges

Just FYI - the day after I posted my original question, I picked up some 
of the TCBOR report tapes at the Timonium hamfest - including the one 
where the Rogowski coil and the calibration procedure is described (I 
haven't had the time to watch it yet).

Steven Roys (sroys-at-radiology.ab.umd.edu)