Special Features:

3971 stamped on coil form

Properties:

An item consisting of a partial turn as one or more turns of wire or other conductive material which constitutes one continuous untapped winding. It may be wound or formed in other than a circular manner and may be self-supporting, requiring no coil form. It is specifically designed to furnish inductive reactance in a circuit carrying radio frequency current ranging from 20 kilohertz (kilocycles) and above. It may include tuning devices, integral resistors and capacitors; however, excludes filter (as modified). The coil has only two electrical terminals. For items having tapped winding or more than one winding - see transformer, radio frequency. For coils wound on resistors, which are designed to be inserted in the circuit of a radio frequency stage to suppress high frequency parasitic oscillations, see suppressor, parasitic.