Simple Jumper Feed Line Choke Optimized for 14-30 MHz
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, CB antennas and others in 14-30 MHz range
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.
16:1 Ununs are useful between coax and long wires with a load impedance near 800 ohms like a beverage antenna. Shortwave listener antennas also can benefit with the 16:1 unun and it may provide a better match than 9:1 ununs – this means quieter noise levels and stronger signals so you can hear distance stations easier.