TV oscilloscope

A special type of oscilloscope was a necessary part of every TV studio in the analog era. Generally, an oscilloscope is a device that shows the changes of an electric signal in time. In analog TV studio, it was used to check the image signal in various parts of the studio. The analog image signal contains two parts - the brightness signal and synchronisation signal. A color signal is added for color TV. The synchronisation part contains line and field synchronisation impulses that tell the TV receiver when to start a new image line or field. We can see these impulses as rectangular blocks at the bottom of the signal. The voltage of the brightness signal is placed above the synchronisation impulses. Its voltage defines the brightness of the particular spot in the line on the TV screen. On the oscilloscope, we can see it as a mix of various curves, as this oscilloscope shows all the lines of the image at once. The shape of the lines corresponds to the contents of the image.