[s-cars] Radio schematics?

[Kirby Smith]

Igor Kessel wrote:

> 
> Kirby,
> Once upon a time, namely back in my radio amateur days in the early 
> 1970-s no special electronics volume control lubricant was available in 
> the old Soviet Union. I used to take a potentiometer apart, rub a soft 
> pencil over the horseshoe shaped resistive track so that a nice fat 
> layer of carbon was left on the surface, after which I would add a 
> droplet of spindle oil on top of it. This would not fix the 
> potentiometer permanently, but it would none the less buy a few mos of 
> service for the volume control.
> 

Igor:

How many times could you do that before the tabs on the shell would break?