Just a note here about noise. Your radio has an automatic gain control which varies the gain or amplification factor inside the radio, to match the signal strength. What this means is that if the radio signal is very weak coming in to the radio, the gain will be boosted and the radio signal will be boosted also. In addition, the noise will be greatly amplified. So, one of the important things is to make sure that the antenna is working properly.
Volume Control: When they have had a lot of use, there is wear that occurs inside the control. The outer finish on the wiper is worn off and the metal underneath oxidizes easily. Also, some of this metal finish and the carbon on the resistor surface becomes a residue and causes problems, which are generally described as a "dirty control". Usually once this happens, the contact cleaner is very helpful but the affect wears off fairly quickly. So, sometimes it is a matter of spraying it once in a while to keep it working properly.
