Every hobbyist wanting to dabble in radio has to – at some point – wind a coil or two, be it the antenna coil of an AM radio, a coil on a toroidal core for a bandpass filter in a communications transceiver or a centrally tapped coil for use in a hartley oscillator. Winding coils is not hard but quite time-consuming. There are different methods of making coils, depending on the area of use and inductance needed.
