The simplest, most cost effective feed line choke is a ferrite ring installed as shown in the picture (at the antenna feed point) to stop feed line radiation or at the radio end of the coax to suppress common mode coax noise current on the coax braid.
Great choke for log periodics, HF beams, Transceiver/Amp isolation
Improves antenna pattern by preventing your dipole from becoming a tripole
Suppresses pesky coax braid radiation and RFI
Reduces coax braid common mode current up to -40 dB ( 6 “S” units) on receive
Use one choke for each antenna feed line
Add a double female barrel connector to act as an “extension” of the existing coax.
Linear Amplifier RFI Kits
LINEAR AMPLIFIER RFI KITS
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.
