Audio Systems: Knob Static, boom boxes, extension tube

Question
I have several radios (some favorite older portables, boom
boxes, etc.) that have over time developed server static in
the volume and tuning knobs when they are moved.
Sometimes tapping it will get it to work better for a while.
After several years it seems to develop in nearly every
radio. What is the cause of this and is there a way to clean
the knobs or repair this problem in some way.

Answer
a good control cleaner and lube will do you well, however, you will have to take units apart to make backside of control accessable. you will find that where the legs of controls are attached to circuit boards, there is a small slot in the metal cover for the back of control. this is where you apply just a little cleaner spray,(with extension tube to prevent gross overspray) work the control back and forth vigorously, and you're all set. do not use on tuners, you must use a non-residue cleaner for those . hope this helps,     g........