Dial Cord Dial String Tuner String Drive Cord 0.5mm (Per 1 Meter)
Radios have a dial drive mechanism to translate motion of the tuning knob into motion of the dial pointer and increase the number of turns required to move the vanes of the tuning capacitor. A system of cords and pulleys is used to move the dial pointer horizontally.
Either the cord is slipping, or broken. If the cord is slipping, take a moment to photograph the cord stringing (or reeving) because you are almost certainly going to re-string it. Do this also if the cord is broken, but otherwise intact.
This simple precaution will save many hours of time trying to second-guess how the dial cord was assembled.
try to find the correct stringing from the radio's service manual. Sometimes the manual for a related radio is available, which can provide insight into how the stringing was intended.