The CHA RFI CHOKE is made of five (5) snap-on cores featuring #31 Ferrite Mix which is the best for this purpose.The #31 Ferrite Mix Core covers 1 MHz to 300MHz.
The CHA RFI CHOKE will prevent, greatly reduce, or totally eliminate common-mode current (which can cause RFI) carried by the coax cable.
They can be installed either at the antenna feed point or right behind the antenna tuner.The choke is composed of the following:
1 X 12" RG-8X
2 X UHF-7614 (Double Female Adapter)
5 X Snap-On core (#31 Ferrite Mix)
Everything is protected by about 10" of black 3:1 Polyolefin Heat Shrink for maximum protection.