If you get the "Sorry, the file cannot be displayed. There seems to be a technical issue ..." error when trying to view an image, a workaround is to click on the cog icon in the upper right side of the media viewer, and then select "Disable Media Viewer". We are aware of the problem and are looking for a solution.
The Tektronix Type 67 was introduced in 1961. It is a time-base for 560-series scopes, providing calibrated sweep rates from 1 us/div to 5 s/div. It uses a 6DJ8 as the trigger input amplifier, followed by another 6DJ8 as a Schmitt trigger.