Ballast inductor

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Esondrmn-at-aol-dot-com>

I wound a new ballast inductor last night using the previously mentioned 7.5 
amp variac core that has a 1/4" slice cut out of it.  I managed to get about 
28 turns of #8 wire on this core.  My previous ballast, using a 5,000 watt 
variac, measured about 25 mh at the one half scale position where I normally 
had it set.  The new inductor measures only .40 mh.  I was surprised it was 
this low.  Is it possible that the Wavetek meter cannot supply enough current 
to magnetize the core, thus the measurements are about what I would get with 
the same number of turns wound around say a plastic form?  If this is the 
reason, why does the meter appear to measure the 5,000 watt variac properly?

Maybe I should hook it up to a low voltage 60 hz source with a series 
resistor and try to calculate the inductance.

Thanks, Ed Sonderman