End Fed Feed Line Choke
Feed Line Choke
Each end fed antenna needs a feed line choke at the radio end of the coax to stop the antenna common mode current (on the coax braid) from getting into the radio when transmitting and also to stop RFI common mode noise when receiving. The simplest, most cost effective choke is a ferrite ring (F240 size) installed as shown in the picture (at the transceiver end of the coax)
Add the Feed line choke (part # EFFLC-240) for $10 to your end fed today and stop the pesky RFI from getting into your radio and causing audio distortion or unexpected operation!