Brb going back to the 1980s….
This is an early model cable converter — it simply let you watch cable channels on a non cable ready TV set. I have many childhood memories of watching shows through one. The top of the box always got so warm, and ours had the piano key selector on a long cable. The control, from memory, is nothing but a big resistor divider that sets the voltage presented to a varactor diode in the tuner, with a couple of logic lines going back from that selector on the left to switch the tuner between three bands. As this was all highly inexact, the fine tuning roller on the right was usually in need of a twist. Set it just right while the right two or more buttons were pressed down at once and sometimes you could juuuust watch the scrambled channels, in weird green picture with horizontal warping around a green and white color bar…!! Shhhhh don’t tell anyone….