01-13-2014, 01:57 PM
If it were mine I would reform them and then check for leakage. Those were very high quality caps and probably will still last longer than a modern replacement.
I have test equipment from the 40's and 50's with the original quality metal can electrolytics and they still test and perform as new. Sprague made a line of long life electrolytics and yours appear to be that type ( "2" in circle on top).
I would connect each section in series with a 100K resistor and then connect to a high voltage supply to reform. Gradually bring up the voltage while monitoring voltage drop across the 100K. As the cap reforms the voltage drop will decrease and the cap voltage will approach the supply. When that happens you are done.
I have test equipment from the 40's and 50's with the original quality metal can electrolytics and they still test and perform as new. Sprague made a line of long life electrolytics and yours appear to be that type ( "2" in circle on top).
I would connect each section in series with a 100K resistor and then connect to a high voltage supply to reform. Gradually bring up the voltage while monitoring voltage drop across the 100K. As the cap reforms the voltage drop will decrease and the cap voltage will approach the supply. When that happens you are done.
