I restore vintage kit and up to know I just replace all caps as I had no way to test them properly. I have managed to get my hands on a mint vintage Heathkit IT-28 capacitor tester. Its a nice piece of kit and allows one to test capacitors for: Capacitance, Leakage and ESR. Not bad for a vintage tester made before 1977.
2 of the results are easy to interpret. Capacitance should be in the design tolerance and leakage should be 0.
As far as ESR goes I'm not sure what is acceptable. It seems it depends on the application. It also seems that higher voltage caps have a higher ESR by design.
Does anyone know what acceptable limits for old coupling caps and power filter caps are?
(Can we please not have everyone telling me that all old capacitors should just be replaced without any consideration. For the most part I agree but I want to keep this thread about the testing and interpreting results so we can learn more.)
2 of the results are easy to interpret. Capacitance should be in the design tolerance and leakage should be 0.
As far as ESR goes I'm not sure what is acceptable. It seems it depends on the application. It also seems that higher voltage caps have a higher ESR by design.
Does anyone know what acceptable limits for old coupling caps and power filter caps are?
(Can we please not have everyone telling me that all old capacitors should just be replaced without any consideration. For the most part I agree but I want to keep this thread about the testing and interpreting results so we can learn more.)
