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.
Coax Feed Line Common Mode Chokes
Feed line chokes are manufactured in a variety of sizes and shapes to make them physically compatible and conveniently installed for various applications. Palomar Engineers offers many different shapes, sizes and frequency ranges and power ratings for just about any application from 200 KHz to 1 GHz.
Need help in selecting the proper choke for your needs? See Choosing a Feed line Choke
