Wall Wart RFI Noise Filter

FSB31-1, ID=1", RFI Range 1-300 MHz, Case of 36 Pieces, FREE USA SHIPPING

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Product Details
MPN: FSB31-1-36
Initial Permeability (@ 10KHz): 1500
Material: MnZn
Max cable size - in/mm: 1.0/25.4
OD (A) - in/mm: 2.22/56.4
ID (B) - in/mm: 1.02/25.9
Length (C) - in/mm: 1.69/41.9
Z (ohms per bead - single turn 1 MHz): 45
Z (ohms per bead - single turn 5 MHz): 90
Z (ohms per bead - single turn 10 MHz): 125
Z (ohms per bead - single turn 25 MHz): 218
Z (ohms per bead - single turn 100 MHz): 375
Z ohms (per bead - single turn 250 MHz): 340
Case/Box lot size: 36
: 36
: 15.28

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 (RFI/NOISE) on each cable.. Full case of 36 pieces - Best bulk rate.

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Wall Wart switching DC power supplies that plug into the AC power line plug and provide DC power to laptops, routers, battery chargers, cell phone chargers, etc are a known source of broadband RFI (a.k.a dirty electricity) that effects many electrical devices including computers, radio receivers, HDTV systems, etc.  In many cases this extra RFI noise effects computer I/O speeds since they have to error correct the information packets many more times due to the noise interference causing packet errors.  A ferrite ring can often increase data throughput by reducing the error correction to normal rates.

A simple ferrite ring filter on the DC power line can help suppress the RFI noise affecting the victim device or keep the DC power cord from acting as an antenna and radiating RFI into other victim devices. This kit is also useful on laptop computer supplies, routers, cable modems, wireless phone charges, etc.

RFI WW Installation 300x288 - Wall Wart RFI Noise Filter

Installation is quick and easy: Just wrap the DC power cord through the center of the ring filter as many times as you can and reinstall.  For best results with long DC power lines, use one at the ring filter at the wall wart end (to prevent the wall wart power supply from using the DC line as an antenna) and another at the DC plug end (to prevent the electronics in the powered device from using the DC power cord as an antenna).  Typical installation is shown below:

The filter suppresses RFI in from .1-100 MHz.   Inside diameter is 3/4 inch/19 mm.

Since most households and office environments have multiple wall warts we offer the Wall Wart RFI Filter kit in bulk quantity packages.

Known RFI Generators include Roku/Sling-TV power adapter - Interference heard in the AM broadcast band
 and harmonics.
Also many ethernet Cable/DSL modems, cell phone chargers, computer power adapters have the same issue:
using the AC or DC side of the power supply as a radiating antenna.

RFI solution is to use a linear power supply, change adapters or wall wart ferrite filters