Im looking for a clamp on ferrite bead to use on a 18 gauge wire. I’m not sure which one to use. If there is one for 14 to 20 gauge that would be great. Thank you
These are the smallest clamp-on style ferrite cores I could find:
Both have inner diameter of 0.138" which would be large enough to double wrap the cable for some of the thinner insulation jacket 18 gauge wires.
If you do two or more wraps, you’ll get significantly better attenuation. With that in mind, here are some others you might consider as well.