Flex Radio 6400/6400M, 6600/6600M RFI kit is designed to be installed on your radio transceiver to reduce Radio Frequency Interference (RFI) caused by common mode current on the coax output (2) of your radio, the AC/DC power cable, mic input, USB transverter RX/TX, speaker, ethernet I/O, and additional I/O cables attached to these beautiful radios.

This kit will help reduce or eliminate:

1. “Hot mic” RFI caused by poor grounding of antennas or common mode currents from linear amps feeding unbalanced (coax fed) antennas without baluns/line isolators.

2. RFI to neighbor’s electronic devices including audio/video systems, computers, telephones, garage door openers, etc.

3. RFI to your other radios, audio/video systems, computers, telephones, etc.

A side benefit is a reduction in noise floor in your receiver depending on the amount of noise being introduced by common mode currents (which are blocked/reduced by the chokes in this kit). You can also choose to add the dual CMNf-500-50 coax common mode noise filters which easily attach to the back panel with double male barrel connectors. Up to 38 dB additional common mode reduction is available with these filters.

These chokes use a special mix of ferrite core material that is effective in suppressing radio frequency interference from transmitters and high noise floor on receivers.

The split beads beads are easy to use, don’t require modification of the protected equipment and work in almost all cases, even when plug-in filters fail.

Use of the chokes often helps cure SWR problems between transceiver and a linear amp and between transceiver and antenna tuner or direct to antenna. The DC power line choke helps keep common mode current out of the power line which could cause interference to other devices connected to the same power line if not suppressed.

This standard kit includes 1 low frequency DC supply filter and 2 coax ring filters (ID=1.4") and 10 1/2" ID split beads and installation instructions or choose the option with dual CMNF-500-50 coax common mode filters in place of the coax ring filters in the standard package.