Reply from FB group Vintage Transistor Radios
Jonathan Eastwood
Said, “… never designed to last over 50 years…”
That’s blasphemous. The germaniums were protected by a hermetically sealed package that used leads made out of kovar which has the same coefficient of thermal expansion as the glass they go through so that no air or moisture can seep inside. As long as the case is sealed the transistor should work for scores or hundreds of years. Now that most of the transistorized equipment uses plastic capacitors and the old paper caps are gone, the plastics should last a very long time too. And if the electrolytic capacitors are replaced with MLCCs that don’t dry out, the radio or other equipment should work for a very long time.
The transistors can withstand very powerful mechanical shocks and vibrations. The circuits they’re in are not as tough, and a lot of the equipment failures are not caused by the transistors. One thing that puts stress on transistors is thermal cycling — going from cold to hot and back.
