an old, electro-decor - variable capacitors of glass, kerosene for a dielectric... Zeiss galvanometers... Siemens milliammeters... Gülcher Thermosäule
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an old, electro-decor - variable capacitors of glass, kerosene for a dielectric... Zeiss galvanometers... Siemens milliammeters... Gülcher Thermosäule |