1ea 85X55X20mm Toroidal Transformer Core 3.3X2.2X0.8 inch Toroid Inductor Ferrite Core Filter Ferrite Ring Chokes Ferrite Bead MnZn PC40

Was having issues with my 40m Hamstick giving feedback to my car's speakers (even with the car off) so I bought this RF choke, wrapped my Hamstick base's coax around it about 8 times and, voila, the RF feedback is gone.

We installed led lights in our meeting room at church which cause the remote control for our projector to be almost unusable (we had to turn off the lights nearest the projector and still it only worked 50% of the time from 6 ft). After installing this we can use the remote with all the lights on and there no problem. We could use the remote from up to 20 ft from the projector with out a hitch. To install just run your power cord of your device though the center and wrap it around the toroid twice.

The price was great and the size was the biggest I could find. I bought them to use in an electromagnetic experiment. I am very happy with them.

Did what I needed two of them to do. In conjunction with some line filtering, got the S7 noise level across the HF bands down to S1.....even less on higher bands. No small feat. I live in an apt...lots of noise on lines.

One of the Toroids has severe pitting on one side. It won't affect the operation of the ring, but it looks really bad. Really disappointed in the quality.

I use these for RF chokes to keep noise out of my radios. Some things need more help than others. This makes a good choke for some of those heavier lifts.

Great size for large (10AWG) DC wires--5 turns and that's it. Best DC noise filter one can make (IMHO).

Used this on my IC7300’ DC cable. Works well.