Equivalent modulator circuits are developed in the form of linear resistance networks. They are equivalent in the sense that the current magnitude in any mesh of the network is equal to the current amplitude of a corresponding frequency component in the modulator. The elements of the network are determined by the properties of the modulator, while the terminating resistances are those physically existent in the connected circuit. With this correspondence demonstrated, the operating features of the modulator may be deduced from the known properties of linear networks. Among the properties considered are the transfer efficiency from signal to sideband, and the input resistance to signal as affected by the sideband load resistance. Equivalent networks are worked out for a number of interesting cases, involving different impedances to unwanted modulation products, together with different non-linear characteristics. The equivalents come out comparatively simple in form under the restrictions noted and followed in the text, which make the carrier large compared to the signal, and the circuit elements purely resistive.