Abstract: A broad-band impedance-matching device for an RF vacuum tube power amplifier incorporates a circuit having multiple inductors and capacitors interconnected in an impedance-matching circuit, said circuit having a low impedance input and high impedance output and made up of a plurality of series connected inductors and capacitors. Impedance transformation is performed in a number of small steps, which enables the use of a much lower cue than would be necessary if the impedance transformation were done in a single step. The arrangement produces an impedance transformation which holds over a relatively broad band width, making in unnecessary for any fine tuning of the network.