Measuring Filter Hum Without a Scope.

Hello Frank,
Yes that is a great tip and I use it all the time quick and easy !
I just used that while testing a old camcorder switch mode powersupply made by Panasonic.

Sincerely Richard

Did you know you can measure the AC component of DC voltage on a bad filter capacitor in a radio or TV set simply by putting your VTVM/DVM in AC volts and seeing the "hum" voltage?

Saves a lot of time and guesswork. And you don't have to dig out a scope. 

This is a great trick to know for you who are new to the hobby, if you are not sure if your filter cap is bad or not. With a bit of experience, you will learn just how much is "acceptable" AC and how much is not. The lower the AC component riding on the DC, the better the supply., or the "more pure" the DC is.

It can be a good learning experience to hook up various old filter capacitors and see just how leaky they are, or how open they are.