On Thu, Oct 21, 2010 at 6:32 AM, Arthur Chance <free...@qeng-ho.org> wrote: > Dredging up physics unused for 30+ years, ferrite is ferromagnetic and > intensifies magnetic fields so a coil of wire with ferrite inside is a > massively bigger inductor then an empty coil. I vaguely remember that brass > is slightly diamagnetic, but could be mistaken.
Bingo. A ferrite slug increases the inductance of a coil, relative to an air core; a brass slug decreases it. I've got a homebrew amateur radio transceiver that uses a coil with a brass machine screw in it for tuning. Wind the screw out of the coil, inductance goes up. A cheap and simple form of permeability-tuned oscillator. _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
