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 known as Big Clamp On. Very useful for AC/DC power, coax cable, etc. Use multiple turns for best results or multiple chokes in series (recommended for large amperage power cables). Always put +/- dc cables through the same ferrite filter so their fields cancel and the ferrite suppresses the common mode current on each cable.. Bulk pack of 3
The ring toroids are useful for AC/DC common mode choking with multiple turns as shown below
 AC Cable on F-240 Toroid – 7 turns |
 DC Cable on F240 – 4 turns |
The ring toroids can also be used on coax or signal lines as shown below:
 RG58 12 turns on FT240 |
 Ethernet Cable on F-240 Toroid – 7 turns |
For RFI/EMI wrap as many turns as possible for higher choking (under 30 mHz).