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
The RFI-ICOM-PS125 is a common mode noise reduction filter set which filters both the AC input and DC output of common SMPS power supplies. These filters effectively isolate the AC power cord and DC output cable from acting as antennas for the internal switching power supply generated noise. The mix 75 filters suppress RFI fundamental frequencies (and the harmonics also) from 150 KHz to 10 MHz. Simple to install on cables without any device modification.
Since the 12 Volt DC cord is very short, we use simple snap on ferrite filters for the DC cable, and a ring filter for the AC power line filter.
Used for amateur and commercial radio transceiver power supplies, cable TV boxes, laptop computers, or any electronic device powered by an external switching power supply.
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).