Depends on what's wrong with it. I've fixed several myself but it's not for the novice.

You need the testing equipment, and a place to get parts from etc... Potentiomiters, Diodes, resistors, tubes, transistors, etc... You also need the knowledge of how to solder, and how to follow circuts in a circut board. Then there are parts not avaliable anywhere else than with another broken radio, exactly like yours to get parts from. And hopefully it's not broke in the same way etc...

First thing I'd check is to look inside for any dry or cracked solder joints, especially where the radio ground wire attaches to the radio chassis on the inside. If it all looks good you can clean the inside of the radio with electronic cleaner if it's really dusty and dirty inside.

Other than that, not much help for it.