Someone wrote me recently about a Capehart early 50s set with controls on the front labeled "Balance" and "Shading". They are shown on the photo in the Sams folder, but there is no mention of them in the parts list, schematic, or elsewhere. Anyone have any idea what they are?

http://www.earlytelevision.org/pdf/Capehart_CT-27-38-45_Sams_160-2.pdf

Balance = fine tuning, shading = brightness. Not merely going by process of elimination, I have one with controls so marked.

Thanks David