Ferrite filter products can help speed up digital devices by suppressing common mode current from RFI sources OR prevent digital devices from emitting RFI on its connecting cables and power supply lines.
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 1.4″ OD/.9″ ID ring toroids as follows:
Mix 77 effective from .1-50 MHz including AM Broadcast band – quantity: 2
Mix 43 effective from 25-250 MHz for general purpose – quantity: 2
Mix 61 effective from 200-2000 MHz for cell phone, WIFI, HDTV, Cable TV interference – quantity: 2
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). For over 30 MHz, 1-3 turns is usually sufficient due the to capacitive effect of multiple turns reducing choking effect.
The rings are also useful for making impedance transformers like 4;1, 9:1, etc.