Consulting the far left side of the schematic it has two wires running vertically, the top left is for your
Looooooooooooooooooooooooooooooong outdoor antenna wire if you wants your SHORT WAVELETS coming in,
and usually that reception is particular about the time of day versus different frequencies.

Differentiating your 2 wires :

The top left ANTENNA wire (brown if still can be made out ) is going in to the band switch.

The left bottom GROUND wire ( black color) is going to a connection to the metal chassis.