[Old1625]

That video genny would not produce audio--just video. But that doesn't mean that extraneous audio static cannot be heard; often there is a video buzz if the fine tuning isn't properly tweaked.

Such a source of video pattern is what was sometimes referred to as a "flying spot" video generator--comprised of a small low-persistence CRT (they have an eerie blue NTSC standard raster on them when you peek down the transparency slot!) and a photodiode tube that sits across from it in the light-tight cabinet. Transparencies with traditional test patterns are inserted in the slot at the top, and rest against the face of the CRT.

The "flying spot" that forms the tiny raster is "eclipsed" by the blackness of the image on the transparency in its travels behind it, and the phototube takes the intermittant light signal that results, and forms the video "stream" sent along with the synch signals to the modulator and RF stages.

I have two of the B&K make--IIRC, and found them very useful in TV work. Aside from the 5:AM pattern I made up numerous other dot and/or bar patterns lithographically that served well in doing linearity and convergence work on color TVs.