Take an inductor and test it at 100 khz which many cheap testers use.? Then do it again with a more costly instrument which more then likely will test at a higher frequency then 100 khz.? This same inductor will read differently.
Lee, w0vt
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On 11/1/2017 4:41 PM, Alan G4ZFQ wrote:
Yes, a scientific fact.
Does this "fact" only apply for iron dust cored inductors because the
equations for the inductance of air cored coils do not include a
frequency term.
Peter
So do iron dust cored inductors include a frequency term?
If so just how much difference?
My tests on air and ferrite cored coils have been with this and using 1% capacitors to make these coils resonant at around working frequency and careful GDO measurements.
People quote that frequency makes a difference, say it's a fact but then do not seem to be able to give examples of when any differences become significant, say more than a few per cent.
73 Alan G4ZFQ
