geoffkait13,658 posts01-21-2019 7:06am
, shielding on power cords doesn’t actually do anything when the rf is coming in on the conductor along with the current. Hel-loo!
Except the shield will stop EMI/RFI from passing through the jacket of the power cord and being induced on ICs and speaker cables that are in close proximity of the power cord.
A simple test to check how well shielding will prevent EMI/RFI from radiating from a power cord is with a signal receiver probe. Just hold the probe next to the power cable outer jacket. If unshielded you will clearly hear the 60Hz magnetic field. You can also hear harmonics that may be on the AC line, like a light dimmer.
Next conduct the same test on a shielded power cord. Depending on how well the cord is shielded there is a good chance you will not hear any sound, noise, from the probe receiver.
Example of a Tone and Probe Tracing Kit.
https://www.amazon.com/Greenlee-701K-G-Professional-Probe-Tracing/dp/B0042VII7A?ref_=fsclp_pl_dp_3
.