Replacing electrolytic capacitors is one of the most common ways to repair (and maintain) vintage electronic gear. This article will explain what these capacitors do and discuss a few different approaches for replacing them. What are Electrolytic Filter Capacitors?
When you begin to restore a set from the 50's or older, it is hotly debated whether or not you should replace all of the paper capacitors or not. Purists and collectors feel that they should only be replaced if absolutely necessary, and if so, the new ones should be hidden inside of the old cap casing for appearances.
Second only to power cords, capacitors are the most failure-prone components in old radios and televisions. In a professional overhaul, it is common to replace all of a set's large electrolytic capacitors and small paper capacitors. This article explains how to do that.
Some kinds of capacitors—paper, molded paper, and electrolytics—are failure-prone and need to be replaced. Other kinds, such as mica and ceramic, rarely need replacement. To avoid wasting time and money, you must be able to tell them apart. Electrolytic capacitors are polarized, meaning that they have positive (+) and negative (-) leads.
Another option to consider when replacing electrolytic capacitors in your gear is to purchase modern axial capacitors with high voltage ratings. Axial caps in particular are useful in power supplies constructed on turret boards, common on vintage guitar amps.
Hold the new capacitor near the place where it is to go, bend the leads to fit, and then trim the excess wire from the end of each lead with the wire cutters. Leave enough length on the lead to allow for crimping it around the terminal. Again, be sure to avoid leaving stray bits of wire inside the chassis.