What is behind that little door in the Baird Televisor?

[kareno]

The 'classic' Baird Televisor - the one with legs and a visible disk housing - has a little panel opposite the viewing tunnel. I'd like to think it's a little cupboard where you can store your tea cakes.

Mr Baird was very forward thinking and would realise that people don't want to miss any viewing while they go to the kitchen for more tea cakes.

[kareno]

Drat! I was hoping someone would say what the panel was for and what the knob does. I'm guessing its not a handle to open a cupboard door...?

[gary]

Rheostat.

http://users.skynet.be/telehor/46.jpg

[kareno]

There's also a knob that operates a gear to rotate the motor case, isn't there?

[gary]

There's also a knob that operates a gear to rotate the motor case, isn't there?

yep - right in the middle at the bottom of the logo plate.