[Hallicrafters] Dial String "twang" on an SX-130

[Julian Bunn]

I am refurbishing an SX-130, and trying to understand why both the 
bandspread and main tuning cords "twang" at various points while tuning. 
I have a similar problem on an S-107. I think I can see what is 
happening: for example, on the bandspread knob's spindle there are about 
three loops of the dial cord, which sit in a rounded groove in the 
spindle. As the spindle turns, these loops move backwards and forwards 
slightly, according to the direction of the turn. As they do so, they 
tend to move up the sides of the rounded groove, and at some point slip 
back, so causing a scrunchy twanging noise (Perhaps I shopuld provide a 
link to an MP3?!) - the dial cord vibrates.

Is this a common problem? How can it be fixed - does it indicate that 
restringing is required?

Many thanks!
Julian