315

The Tektronix Type 315 and 315D are single-channel oscilloscopes from the 1950's. They use 3WP2 3-inch CRTs and are mechanically similar to early 500-series monolithic scopes such as the 511A. The scope slides out of the case instead of having removable side covers as were used in the 53x, 54x, 55x, 56x, 57x, and 58x designs. What is the difference between the 315 and the 315D?