Line Isolators/Common Mode Chokes

Common Mode Current (CMC) carried on the outside of a coaxial cable braid from your antenna can cause unwanted RF in your radio shack and can radiate this unwanted RF into you and your neighbor’s electronic devices.  These currents can burn your fingers on the key or lips on your microphone and they can cause computers and other devices to fault or stop working when you transmit.  They can also cause TVI, BCI, and a knock on the door from angry neighbors!


To reduce CMC on the coax you can use a Common Mode Choke.  These chokes come in many varieties for various frequency ranges, mechanical attachment methods, choking impedance and cable size.  Palomar Engineers offers three choices including Sleeve Baluns, Super Choker™ and CUBE Baluns™ in a range of choking impedances and topologies for small and large cable sizes. Clink on the links for more info on these items.


5 section balun

SLIP ON Baluns for 1/4″, 1/2″, 1″ cable

Kit 105 Installed on RG-58 Cable

SNAP ON Kit 105 Installed on RG-58 Cable




Sometimes you need a common mode choke that is super effective and the Super Choker™ is our solution for frequencies below 10 Mhz.  Very useful for operation on the 160, 80 and 40 meter bands.  Click here to learn about this great choke.

Super Choker II using Mix 31 for 160-20 meters - 1.5KW

Super Choker II using Mix 31 for 160-20 meters – 1.5KW




Current Unun and Balun Enclosure – CUBE Baluns™ are ferrite toroid baluns and ununs available in weatherproof enclosures with various input and output connectors.  Available assembled and as kits and available in 1:1 (Chokes/Baluns), 4:1 (Baluns/Ununs) and 9:1 (Baluns/Ununs).

CUBE Baluns™

1:1 5KW CB-1-1500 CUBE Balun™

Got a question about using ferrites?  Check out our Application Notes page for more info on RFI and using common mode chokes.

Still need Help? Drop us an email at  and we will be glad to answer your question.