Common mode current carried on the outside of a coaxial cable can cause unwanted RF traveling back to your operating position causing many issues. Another common issue is that the coax will become part of the antenna system and begin radiating RF. In most instances this is undesirable and can negatively impact antenna performance and tuning. The CM7 is a US made inline 1:1 common mode choke which solves this problem in a compact and streamlined manner. Consisting of 7 mix 31 ferrite beads and 240 series (RG8X) Ultra Flex coax the CM7 provides 35-40 dB of attenuation from 1 MHz to 300 MHz.
 
Simply place the CM7 at the feed point of your antenna and attach your exiting coaxial cable to the other end. The CM7 can be used with many popular antenna types such as EFHW, dipoles, random wires, verticals, etc. to improve tuning consistency and performance. Many antennas require the use of a 1:1 choke to isolate the coaxial cable from the antenna system for proper performance.