Wanted, Diodes
On Aug 28, 7:29*am, raypsi wrote:
On Aug 27, 3:58 pm, K7ITM wrote:
I'd bet that the shorted-turn effect is very much larger than the
permeability effect with respect to changing the inductance of the
oscillator coil.
Cheers,
Tom
I agree, except Air has no permeability, you can't magnetize air. You
can't magnetize brass.
I think you're confusing permeability with susceptibility. Even vacuum
has non-zero permeability.
I'm still considering Tom's points. What I know from decades of
experience, is if I put a brass slug into a solenoid, the inductance
goes down by a little bit. "Little" is relative to the effect of a
ferrite slug, which makes inductance go up by a lot in comparison.
The "little" is key for the PTO designs I mention, it allows rather
fine tuning with very simple mechanicals. If I think of it as shorting
turns as it moves in, that is completely out of whack in my head with
the observed changes, because shorting all the turns causes a big
change in inductance, not a small one.
Tim N3QE
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