COLIN WONFOR: Power line noise

Colin - can we get meaningful measurements of power line noise? Is the noise too low-level to measure without exorbitantly expensive equipment? What equipment is required? Outside of laboratories, who has it? We buy all sorts of devices to clean up power. So why can't we measure the noise that's there and target it? Wayne Rydle


Hi Wayne, you can see on a scope but better still on a spectrum analyzer. You need a box called a LISN, this has a large filter that is tuned to reject input noise so you can test the noise a piece of kit is producing but if used correctly I can be used to analyze mains born noise also. They are fairly simple to make but beware of that nasty bite that the mains has and if built wrong lots of smoke.