TE>From: Esondrmn-at-aol-dot-com
TE>To: mark.graalman-at-mediccom.norden1-dot-com
TE>Subject: Current transformers

TE>Mark Graalman

TE>You are correct, air wound pick up coils do not work.  Last night I tried
TE>using a coil out of a large solenoid.  It is wound with small wire, like #30
TE>awg, thousands of turns on a plastic form.  I passed the main RF ground wire
TE>from the secondary through the center.  Running the coil at half power, I
TE>could not measure any AC voltage on my meter.  I built a full wave diode
TE>bridge and put a .005 mfd capacitor across the outputs.  I could see the vol

TE>meter just barley move on the lowest DC voltage scale.  I switched the meter
TE>to the 25 microamp current scale and could measure a couple of microamps
TE>which did change as I varied the power input to the coil, but not much.

TE>I hauled all my old televisions to the dump years ago.  I guess I will have
TE>to call some TV repair shops and see if I can find an old flyback

TE>Ed Sonderman

Ok. I have done this with air wound coils as I said before. BUT I
reckon I must have had an amount of 50 Hz component in the RF. In
those days I wasn't using any proper grounding system. so I was
tuning to 50 Hz rather tha true RF.

As I said before: some strange things happened and the exercise
wasn't all that useful for tuning, but it might be a good
indicator of mains component. (In New Zealand we use 50 Hz)

Jim Oliver <jim.oliver-at-welcom.gen.nz> (3:771/370)

 * SLMR 2.1a * "I am Homer of Borg! Prepare to be ..OOoooo ! Donuts !!!"