2" Miniature TV/Radio Strange Problem

[compucat]

I purchased a Broksonic 2 inch TV and AM/FM shortwave radio. This is that set that was sold under many different brand names including Realistic. I have a Realistic branded version but I have always wanted the one with shortwave band. I found one in practically unused condition with all accessories. The original owner bought it to use during storms and it was only used twice. the trouble I am having is with the radio. At first, the radio would work intermitently. Resoldering the function selector switch sorted that out when Deoxit did not help. While the radio works consistently now on AM and shortwave, the FM band sometimes loses reception starting with the upper end of the dial and gradually moves downward. If I leave it off for a day it comes back and works fine. Using the TV seems to bring it on if I have the TV on for an hour or so then switch to FM it acts up. It does not seem to be a bad connection as far as I can tell. I am wondering if an electrolytic cap can cause this as a result of the set sitting unused for almost the past 29 years. When I had the set opened up there were no electrolytics leaking or bulging. Everything inside looks factory fresh. I really want to use this as the radio is nice and the TV is functional with my agile modulator. I have never had a problem with one of these sets except a Unisonic version that would blow the internal fuse when the batteries got weak. These are generally well made little sets that sold for $200 when new 30 years ago. I would be interested in any suggestions.