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Capasitor block replacements, philco model 20
#4

The small value electrolytics like 1 or 2 uF sold today are not rated for the amount of ripple current they will be subjected to in a vintage radio power supply. They are physically tiny and cannot dissipate the heat created by the charge and discharge currents flowing through their high effective series resistance. In use they will overheat and eventually fail.

A film cap has a very low ESR and will not have this problem. The original caps were paper and more closely resembled a film cap than an electrolytic.

The best choice for replacing these low value paper filter caps is a metallized film style cap. They are cheap enough and will last almost forever, so practically speaking you will never need to replace them again.





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