This Extra Large size Ring and Snap-On Combo Pack is our BEST VALUE and a convenient solution for troubleshooting RFI/EMI (200-2000 MHz) with various diameter cables ranging from 1.4" to 1.4"/35.6mm for use as either single turn or multiple turn RFI filters. Great for Grab and Go portable operations or general RFI and noise suppression.
The filters are useful for RF coax, AC/DC power cables, Ethernet, data, audio/video and device interconnection cables.
Always use a snap on or ring 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 turn). Included in these combo packs are our most popular snap on sizes as follows:
Extra Large Combo Pack includes the following:
F240-61 ring – 1.4″/35.6mm ID – 6 pieces
FSB61-1/4 – 1/4″/9.5mm ID – 12 pieces
FSB61-1/2 – 1/2″/12.7mm ID – 10 pieces
Normal Retail price is $194 for these parts bought individually. You also get FREE USA SHIPPING for this item.
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