• 06/07/2022 3:29 pm
  • Georgia
  • Sell
For coax fed dipoles, verticals, beams, Slopers, Loops, Windom, OCF, and Yagi antennas Many companies often call this item different names to make it difficult to compare the same item between companies. A line isolator is also called a common mode choke, a 1:1 balun, a 1:1 unun, a current balun/unun, a feed line current choke, and a 1:1 Guanilla balun/unun/choke. All these names are for the same item: a common mode current suppression device that works to suppress common mode current on the outside braid of your antenna feed line. The purpose of the common mode choke is to suppress or reduce the common mode current shared by all the wires in a cable of one or more wires. In the case of coax feed line, the center wire and inside of the coaxial braid carries the RF signal current and the outside of the braid can carry common mode current if it is not choked at the antenna feed point. A choking impedance of 400 ohms or more should be used. Adding a common mode choke, with sufficient choking impedance, at the antenna feed point will keep the RF signal on the antenna and off the feed line.


  • Specifications:
  • Frequency: 1.8 - 30 MHz
  • Through-line impedance: 50-ohms (nominal)
  • Insertion loss: less than 0.2 dB at 60 MHz Inductance 70 uH
  • Choking Impedance1539 Ohms at a Frequency of 3.5 Mhz
  • Power handling: 3kW
  • Load mismatch tolerance:
  • up to 3:1 VSWR at 3KW
  • Connectors: PL-259