Palomar Engineers has RFI kits for many brand specific linear amplifiers as well as generic RFI kits for both AC powered and DC powered linear amplifiers.

Purpose. These kits are designed to choke common mode currents going into or exiting from your rig. Chokes are supplied for the RF In, RF Out, Relay Cable, and AC/DC power line. Use of the chokes often helps cure high SWR problems between exciter and power rig or between power rig and antenna tuner or direct to antenna. The AC/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.