12-21-2021, 05:53 PM
Electrolytic filter caps began appearing commercially in radios in the late 1920's. The first instance I am aware of was in a Crosley Bandbox from 1928. It had a large cylindrical cap labeled "Mershon Condenser". It was a triple section liquid filled wet electrolytic.
Commonly, elecrolytics appeared more frequently in radios around 1931 or so, replacing the large paper filter cans.
I believe both of the caps in your photo are paper. The cylindrical one appears to be a hermetically sealed oil filled cap, given the capacitance is only .47 uF, and is a lot newer than the other.
What are you using for the power supply of your 1920's radio? These sets were designed to run on batteries for both the filament and B+ supplies. Is it a later set with a built in supply or battery eliminator?
Commonly, elecrolytics appeared more frequently in radios around 1931 or so, replacing the large paper filter cans.
I believe both of the caps in your photo are paper. The cylindrical one appears to be a hermetically sealed oil filled cap, given the capacitance is only .47 uF, and is a lot newer than the other.
What are you using for the power supply of your 1920's radio? These sets were designed to run on batteries for both the filament and B+ supplies. Is it a later set with a built in supply or battery eliminator?
