HAM Radio 101

Word of the Day: Ferrite–What it is and Why You Need It

If your station suffers from radio frequency interference (RFI), today’s Word of Day, ferrite, should become an immediate and permanent part of your Ham Radio vocabulary. Different mixes of ferrite—a ceramic made from oxides of magnetic metals—have proven to block and dissipate RF currents. Extensive testing has shown that each mix works best over a certain frequency range. DX Engineering ferrite RF noise reduction toroids and beads are color-coded so users can select the right choke for the right application at a glance:

31-Mix, Blue—1 MHz to 300 MHz
43-Mix, Silver—25 MHz to 300 MHz

52-Mix, Orange—200 MHz to 1 GHz
61-Mix, Red—200 MHz to 2 GHz
75-Mix, Green—150 KHz to 30 MHz
77-Mix, Pink—100 KHz to 50 MHz

DX Engineering offers Color-Coded Ferrite RF Noise Reduction Kits featuring bead/toroid combinations designed to suppress RFI in AC/DC generators, HF base stations, AM broadcast radios, and linear amplifiers. Other kits, such as DXE-TC43-14-10 (ten .90 inch I.D. 43-Mix  toroids) can be used for a variety of applications. Choose from 29 kits.

Also available from DX Engineering are High Impedance Common Mode RF Choke Kits, featuring 40, .500 inch I.D. 31-Mix Toroid Beads (DXE-RFC-160-20) or 30, .500 inch I.D. 31-Mix Toroid Beads (DXE-RFC-20-10). Kits come with heat shrink tubing to secure the beads in place. The beads slide over any standard .405 inch coaxial cable.

For more details on what is ferrite, what is a ferrite choke, and what is ferrite used for, click on these links for articles from OnAllBands blogger Ward, N0AX.


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