That is probably the best presentation I've ever seen on any subject.  Extremely well done.

I learned two additional tricks that I'll add here to supplement your presentation in the "locating the noise section:

Tune a AM-FM larger size portable radio with a larger ferrite bar antenna to a unoccupied frequency nearest 850 kHz as it seems that the receiver is most sensitive to noise at that frequency.

When using this radio to triangulate the location of the offending noise source, often the noise will peak around a cluster of possible objects: example: the noise peaks around the electric service entrance in the basement which is next to the oil burner and water heater which are all in close proximity to each other and the offending noise is extremely loud. It's here somewhere!

At this stage of noise detection, switch the receiver to FM, and extend the telescoping whip, finding a frequency that's unoccupied by a station, and move around with the whip trying to find a peak in the noise.  Usually an FM receiver is designed to reject this type of noise until it is extremely loud which it will be when it is nearest the noise source. In fact, when you get within one or two feet, you will need to retract the whip to continue to locate the noise. When the whip is fully retracted and the noise is still extremely loud and you're still unsure of the noise source, touch the whip to any metal of nearby objects, when you find the offending object, like in my case, a defective doorbell transformer, the noise will be overwhelmingly loud. 

73

DR

N1EA