Original poster: "Chris Swinson by way of Terry Fritz <teslalist-at-qwest-dot-net>" <exxos-at-cps-games.co.uk> Hi all, If I have a coil which has a frequency of say 100khz, could I build a coil which is say 50khz, and add a capacitor in series or parallel across this coil to make it look like it is 100khz ? is that makes sence..... Thanks, chris