LF: ferrite coil

["mal hamilton" <g3kevmal@talktalk.net>]

Jim es Co

Instead of winding a tight coil on to a ferrite rod to get 270 uH and tuning with a 250 p variable capacitor, instead wind an air core coil and move the ferrite rod into/out of coil for the required inductance necessary for frequency of interest. This would further reduce losses.

Coil former just sufficient inner diameter to accommodate ferrite rod(s) so size is virtually the same.

 

mal/g3kev