uxcell 15mm Ferrite Cores Ring Clip-On RFI EMI Noise Suppression Filter Cable Clip, Black 10pcs

Using these ferrite cores on wires going in and out of my vacuum tube guitar amp really helped reduce background RF interference noise and hiss. Quite happy with this product.

I have a decent headphone amp and dac hooked up to wiim pro but everything is connected to a surge protector which a microwave and lights and a coffee machine is hooked up to as well, after putting the ferrites in different places and looped some of the cables and eventually I was able to get all the noise out of it and everything is crystal clear now

I have one of these on most cables in my ham radio station. They really helps to eliminate computer and "wall wart" hash on receive and transmit RF getting into computer speakers and other audio equipment. Always put as many turns of cable as you can fit into the ring, as this is much more effective than just clamping it onto the cable..

Perfect size for multiple winding turns of small diameter cables and wires. Very effective for filtering noise in my amateur radio gear.

didn’t do anything to help with any electrical interference. Seller is good though. Easy purchase and return.

Inductance is proportional to turns-squared so 1-turn (just clamping it over a wire pair) is 0.25 uH, 2-turns (if two will fit) is '2-squared' = 4 x 0.25uH = 1 uH, 3-turns would be '3-squared' = 9 x 0.25 = 2.25uH, etc. You can also add several of these in a row to increase RF filtering. Common mode rejection requires that both wires go through the ferrite core in the same direction (typical use). Differential mode noise rejection where noise is entering by just one wire requires that both wires go through the core in opposite directions.

So far so good, the larger diameter center hole work with cables that you want multiple passes (attenuation is the ^2 of the number of times the cable goes through if I'm remembering it correctly )

These ferrite cores are large enough to fit on the electric wiring for my air handler, AC comressor, pool pump, and tankless hot water heater. I've had lots of circuitry die in my air handler and I'm hoping that these can help suppress surges and high frequency noise that might be damaging the circuits. Time will tell, but between panel surge protection and ferrite cores I hope that I can have fewer failures.