Transceiver RFI Kits

 

F240-31, ID=1.4", AC/DC/Coax Noise Filter, RFI Range 1-300 MHz, AKA FT240-31

SKU F240-31-1
$9.99
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F240-31, ID=1.4", AC/DC/Coax Noise Filter, RFI Range 1-300 MHz, AKA FT240-31
Product Details
MPN: F240-31
Country/Region of Manufacture: China
RFI Range (MHz): 1-300 Mhz
ID-B (in/mm): 1.4/35.6
OD-A (in/mm): 2.4/61
Height-C (in/mm): .5/12.7
Weight (oz/gm): 188 grams
Initial permeability: 1500
Case/Box lot size: 100
Frequency (MHz)/Single turn impedance (ohms): 1MHZ: 12 ohms, 10MHz: 40 ohms, 25MHz: 63 ohms

Very useful for AC/DC power, coax cable common mode current suppression. For highest choking resistance, wrap cable through center of ring as many turns as possible. DO NOT use for impedance transformers (2:1, 4:1, 9:1, etc.) - use Mix 43 or Mix 61 for high power.

All F240-31 singles individually labelled with specifications for ease of identification.

Customer Feedback:

At 100 watts on 40 meters, my CW sidetone used to be the smoke detectors in my house! After installing a set of ferrite rings on the 120V and 12V lines, I can finally work 40 meters CW without hearing my code through the smoke detectors. Thank you!
Paul
K7SHR

 

Also make sure you connect a good RF ground to the transceiver ground post.

Note to Flex Radio users:  Use snap on ferrites for firewire cable, speaker cable and mic cable,  Ring ferrites for Antenna output and DC power.

For additional RFI suppression, use a feed line choke at the antenna to suppress common current on the coax feed line – see our store for feed line choke alternatives for use at the antenna.

 

If you use a linear amplifier we have RFI kits for linear amplifiers that help suppress RFI in your shack or in your neighbor’s house.