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.
The impedance transformers are classified in ratios of 2:1 (100:50 ohm) to 16:1 (800:50 ohm). The outputs can be configured as balanced (Balun) or as unbalanced (unun) with respect to the inputs which are considered all unbalanced coax at 50 ohms. All impedance transformers are designed for 1.8-31 MHz unless otherwise specified.