Ferrite Ring Combo Pack

The Ferrite Ring Combo Pack is a convenient solution for troubleshooting RFI/EMI from unknown frequencies or multiple frequencies that require multiple  suppression mixes.  Included in this combo pack are ten 2.4″ OD/1.4″ ID ring toroids as follows:

Mix 75 effective from .15-10 MHz including AM Broadcast band – quantity: 3

Mix 31 effective from 1-300 MHz for general purpose – quantity: 4

Mix  61 effective from 200-2000 MHz for cell phone, WIFI, HDTV,  Cable TV interference – quantity: 3

Also available in .9″ ID for smaller projects


The ring toroids are useful for AC/DC common mode choking with multiple turns as shown below

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AC Cable on F-240 Toroid – 7 turns

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DC Cable on F240 – 4 turns

The ring toroids can also be used on coax or signal lines as shown below:

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RG58 12 turns on FT240

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Ethernet Cable on F-240 Toroid – 7 turns

For RFI/EMI wrap as many turns as possible for higher choking (under 30 mHz).