RE: acmi error found? (LCR meters)

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Gary.Lau-at-compaq-dot-com>

I can't agree that inexpensive LCR meters can't be used with primaries.  I
have a Wavetek 27XT, in the neighborhood of $100.  My previous primary was
69uH, and it always gave reliable readings.  Today I decided to test it on
my new high-inductance primary.  As a reference, I measured the resonant
peak with a frequency counter.  The cap is a Maxwell with a printed value of
.0196uF.  The Wavetek reads .0193uF.  If I use the printed C-value, the full
primary calculates out to 225uH from the measured Fres.  The Wavetek reads
227uH, though there is about +/- 4uH of "noise" (I noted the highest and
lowest values seen and averaged them).  If I tap in a few turns, L
calculates out to  169uH, again with noise, and the meter reads 171uH.  I
without reservation recommend this meter, as it's the only inexpensive one
I've come across that can measure inductance, capacitance, and frequency,
plus the usual V, I, & R.

Regards, Gary Lau
Waltham, MA USA

>Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>
>
>An LCR meter is great for the secondary, caps, and all kinds of other stuff
>but they are pretty bad for the primary inductance.  The inductance is so
>low that LCR meters are pretty bad.  I used a scope, frequency generator,
>frequency counter, and the HP 34401a to detect the absolute peak in my
>measurements.  Yips!  that's about $3000 bucks worth of toys!!  But get the
>LCR meter!  They are invaluable and I use mine all the time!  The B&K 878
>or 875 are fine toys!  I have an old Elnico but I use the B&K's at work.
>Stanford makes a super ultra nice one but it is an extra grand :-(.
>
>Cheers, Terry