Simple Dipole Feed Line Choke for 1/4" coax (1.8-61 MHz)
The simplest, most cost effective feed line choke is a ferrite ring installed as shown in the picture (at the antenna feed point).
Improves antenna pattern by preventing your dipole from becoming a tripole
Prevents pesky coax braid radiation and RFI
for best results use multiple turns through center
Use one choke for each antenna feed line - take a 3 foot piece of G-8X (part# RG8X-3) and wrap 10-12 turns thru center for a good feed line choke.
Also make sure you connect a good RF ground to the transceiver ground post.
Note to Flex Radio users: Use snap on ferrites for firewire cable, speaker cable and mic cable, Ring ferrites for Antenna output and DC power.
For additional RFI suppression, use a feed line choke at the antenna to suppress common current on the coax feed line – see our store for feed line choke alternatives for use at the antenna.
If you use a linear amplifier we have RFI kits for linear amplifiers that help suppress RFI in your shack or in your neighbor’s house.