[Boatanchors] Q of electrolytic capacitors

[Brian Clarke]

Q is not an important measure of the quality of a capacitor. Firstly, Q depends on the 
frequency at which it is measured - which often is quite different from the frequency at 
which it is used; and secondly, Q depends heavily on how you measure it.

If you really want a good measure of the quality of electrolytic capacitors that are to 
be used in power supplies or as bypass capacitors, measure the equivalent series 
resistance [esr]. This requires a special piece of test equipment. A kit for this 
featured in at least one of the electronics mags a few years ago. 

73 de Brian, VK2GCE.

You asked:

My questions is what is the appropriate value of Q for a good electrolytic
capacitor?