Rob1, a jouneyman electrician never would know about it. A typcial one wouldn't. My lab tech has creditials like you, and was shocked on how much he didn't realize about electronics when he came to work here. We both taught each other alot. He showed me proper grounding techniques, and home wiring expertise, we showed him about ground loops, and very specialty electronic gear working in the RF world. So he was a smart feller that could live in both worlds of high frequency analysis and home wiring which is rare. They rarely use occilliscope's or spectrum analyzers, in fact only time he looked at a specturm was in tech school. Typical home appliances have enormous dynamic range for voltage fluctuations. Almost all your home sterios, and TV's are immune for high frenquecy spikes due to almost all the power is converted to DC thru a typical 4-way bridge, and capacitance inline for filtering out such. Of course washers dryers, ovens, and lights are even more immune to the issues, as washers work on AC motors and could care less about a 10V 2KHz spike, ovens just heat an element. The human eye can't pick up a 2KHz-10KHz change in light, and even if it could the capacitance in a light would filter it out.

A peizo electric devices and tranducers unfortunatly works on a different set of rules in the uV range. uV is .001volts. Compare that to 110v AC. Yes, at my company, we use the digitals also. We have our own power, and are immune to the outside world. Totol different set of rules for proper commercial power. Since you are a journey man you know all about different standards for grounding for a commercial 10 story goverment building and mossy oaks split foyer in a developement so you actually could easily school me in stardards. I know I sure as crap don't know everything, but these devices, I do have a grasp on. hey, if you don't believe me or think I am full of it, just ignore me.