Abstract
A simple model of the electrical characteristics of thin‐film‐bridge, point‐contact, and tunnel junction Josephson devices is given, along with some comments on their relative performance at very low and at very high frequencies. A particular example is the dc IV characteristic of a point contact at the center of a parallel‐disk microwave cavity. Some recent developments in devices and the application of a point‐contact loop (SQUID) device to magnetocardiography is described.