pdp-8/l supply

Brad wrote: You don't really need an ESR meter for that. A lab power supply (i.e., adjustable current limit) will work fine. For a DC power supply, the main things you look for are: 1) Is the capacitor excessively leaky at the operating voltage? It shouldn't pass much DC. Set the PS voltage to the operating voltage of the capacitor, and set the current limit low (say tens of mA). Connect the capacitor and see what the voltage does. If the capacitor is good, the PS will start in current limiting, and the voltage will go up linearly as the capacitor charges. Eventually the voltage will hit the supply setting, and the capacitor should draw almost no current at this point. If the voltage gets stuck at some point, that means the capacitor is leaky. It may just need reforming; if so, leaving it on the PS for a while may do the trick. 2) Is the capacitance within spec? Measure how long it takes to charge. If you're using constant voltage, the rate of charge exhibits exponential decay. If you use constant current, it is linear. Eric