The Ferrite Snap On Combo Pack is a convenient solution for troubleshooting RFI/EMI with various diameter cables ranging from 1/4″ to 3/4″ for use as either single turn or multiple turn ferrite chokes. The snap on chokes are useful for RF coax, AC/DC power cables, and device interconnection cables.
Always use a snap on with a larger inside diameter than the diameter of the cable and use multiple turns if possible (2 turns through the snap on is the same as 4 snap ons with 1 turns). Included in these combo packs are our most popular snap on sizes as follows:
Mix 75 Ferrite Snap On Combo 8 pack (RFI Suppression range is 150 KHz – 10 MHz)
FSB75-1/4 – 1/4″ ID – 4 pieces
FSB75-1/2 – 1/2″ ID – 2 pieces
FSB75-3/4 – 3/4″ ID – 2 pieces
Normal Retail price is $140 for these parts individually - this items qualifies your USA order for free shipping.
Excellent for AC/DC power cables on switching power supplies, variable speed motor controllers, and data/audio/video cables for AM broadcast RFI suppression.
AM broadcast transmits on a low frequency with large antennas. Consequently it takes a large antenna to receive the signals. Typical “antennas” are AC house wiring, phone lines, long satellite or cable TV cables, DSL/CAT5 lines running between rooms, etc. The device wires that connect to these “antennas” need to be choked with as many turns through the ferrite as possible. Some installation examples are shown below on this page.
For AC/ DC power cords and coax cables the F240-77 (2.4″ OD, 1.4″ ID) “Donut” toroid is the most popular. Also available are smaller toroid donuts and Mix 77 beads. Shown below is a graph with 8, 10, and 12 turns through the toroid – obviously more turns has higher choking impedance. Mix 77 toroid products are HERE and Mix 77 small beads (for small wires) are HERE
F240-77 Turns Comparison from .1 – 8.1 Mhz
Shown below is a graph of frequency response verses choking magnitude for a F240-77 in the AM Broadcast band for a 12 turn coil around the toroid. (Same info as above but different frequency range).
F240-77 Choking Impedance in AM Broadcast Band
Typical Installations for Donut/Ring Toroids
 AC Cable on F-240 Toroid – 6 turns |
 Ethernet Cable on F-240 Toroid – 7 turns |
 Audio or Mic cable on F240- 12 turns |
Extra Mix 75 Snap On Beads HERE – VERY effective for AM Broadcast RFI