Several Tektronix products used the Phantastron circuit which can generate very linear and very long ramp signals and displays. The Phantastron was originally used to generate a comparison pulse for use in timing radar returns thus estimating the distance to the target. The Type 512 and the Type 524AD oscilloscopes utilized Phantastron circuits.

In 2021 volunteer Phil Crosby gave a presentation on the Phantastron circuit to TERAC. Click on the image to view the PDF.