RF Chokes/Ferrite Beads, do they have a place in your system?

Ferrite beads/clamps roughly act as a transformer where the primary is the cable or wire in the clamp and the secondary is shorted.  The end result is that high-frequency current is converted into heat.  Since the high-frequency (EMI) currents are fairly low unlike 50/60Hz mains currents, the amount of this heat is minuscule.  Absolute majority of ferrite materials are targeting high-frequency spectrum (tens of MHz and up).  They don't address low-frequency (tens of kHz to few MHz) conducted noise that is prevalent on AC power.   The main purpose of ferrite beads/clamps is to reduce radiated emission (30MHz and up) for EMC test - any cable is an antenna and these ferrites introduce losses making what would be a good antenna a bad antenna.  One should expect perhaps 10dB attenuation which may be just enough to pass CE/FCC radiated emission test.  If you are looking to reduce conducted noise on AC mains, ferrites would be of very little help - you would need to have an AC EMI filter for that.

For one thing current doesn’t have a frequency. At least not the last time I looked. 👀 Besides ferrites hurt the sound. So the technical description is kind of moot.

For one thing current doesn’t have a frequency. At least not the last time I looked

How do you think inductors work??

I’m not sure we’re on the same page, as one senator once said to another. 🤗

Thanks all, I appreciate the description of how a ferrite choke works.

I have noticed that certain electronics in my home such as some HDMI cables, computer system cables, and power cables came from the manufacturers with chokes molded right into the cable or clamped on such as my Audioquest power cable. What is it that these manufacturers are trying to accomplish by installing the ferrite chokes on all of these different types of cables? Are they trying to reduce radiated noise or are they trying to stop something from entering the equipment from the AC mains or something in the signal chain? Thanks!