Does anyone know what this knob is for?
 

I have this Philco console, and it does have four adjustment knobs: vertical, horizontal, brightness and range. What was the function of this "range" control?

Could the range control be for local/distant stations?

Sounds similar to Truetone's "Rotoscope" control that's some sort of antenna attenuator.

Clean Philco, BTW! :)

It's an attenuator. There weren't many stations in the early days of TV broadcasting so they made the front ends very sensitive to allow for poor aerials and distance. If you had a station nearby it could overload the front-end, so hence the attenuator. As more stations signed on, the overall sensitivity of sets lessened. In 1972 we replaced our '59 color Admiral with an RCA and it was a dog in comparison. Horrible audio compared to the Admiral and extremely insensitive. Had to boost the hell out of the signal to avoid ghosts and snow.

I have a table model like that. You didnt mention a contrast control. Mine has no "range" control. The other funtions you mentioned plus contrast should be 4 small knobs behind that plastic nameplate. The knobs and nameplate I am still looking for by the way, if you have any spare parts. Does your set use a 21ZP4B crt or some othe tube?

Thanks for the answers. This TV looks almost like new. I bought it from the largest TV collector in Brazil. I still don´t know what CRT it uses, because I didn´t had the time yet to take out the back cover ans take a look inside. Unfortunately, I don´t have any spare parts.