High quality clip on ferrite to suit up to 10mm ( RG-213 , RG-8 , LMR400 , SLMR400 )cable or wire
These fit onto 9mm to 10mm O/D coaxial cable with a nice firm fit. They are also ideal for USB cables with up to 4 turns of cable onto core eliminating noise from the device. May also help to stabilise SWR so that touching cable connectors no longer affects the SWR.
Ferrite Mix 31 (MnZn) is a specific Manganese-Zinc (MnZn) magnetic material formulated primarily for broadband electromagnetic interference (EMI) and radio frequency interference (RFI) suppression. Originally developed by Fair-Rite, it has become an industry standard in RF engineering and communications for taming unwanted noise and common-mode currents.
Superior for lower frequencies (1 MHz to 10 MHz). It provides a much higher choking impedance in the lower HF bands. Mix 31 suppresses RF noise through two distinct mechanisms depending on the frequency:
The Reactive Region (Lower Frequencies (~1 to 10 MHz): At the lower end of the HF spectrum, Mix 31 operates primarily as an inductor. The magnetic permeability of the core concentrates the magnetic field, significantly increasing the inductive reactance of the wire passing through it.
- The Filtering Effect: In this region, the ferrite opposes changes in current. It essentially acts as a reflective barrier, bouncing the common-mode energy back toward its source rather than absorbing it.
The Resistive Region (Higher Frequencies ( ~10 to 300 MHz): As you move higher in frequency, the physical characteristics of the Manganese-Zinc (MnZn) material change. The magnetic domains inside the ferrite can no longer flip fast enough to keep up with the alternating RF current.
- The Filtering Effect: The core becomes highly "lossy." The inductive reactance drops off, and the equivalent series resistance becomes the dominant factor. In this region, Mix 31 acts like a frequency-dependent resistor. It absorbs the RF interference and dissipates it harmlessly as minute amounts of heat. This broad, lossy characteristic is exactly why Mix 31 is the go-to material for taming severe EMI/RFI issues.