Coax Feed Line Common Mode Chokes
Feed line chokes are manufactured in a variety of sizes and shapes to make them physically compatible and conveniently installed for various applications. Palomar Engineers offers many different shapes, sizes and frequency ranges and power ratings for just about any application from 200 KHz to 1 GHz.
Need help in selecting the proper choke for your needs? See Choosing a Feed line Choke
12:1 Baluns are useful between 600-650 ohm balanced loads the impedance at the end of the feed line is 600 ohms (1/2 wavelength feed line), or high impedance feeds for rhombic, T2FD and traveling wave antennas.
12:1 Ununs are useful between coax and long wires with a load impedance near 600 ohms like a beverage antenna. Shortwave listener antennas also can benefit with the 12:1 unun and it may provide a better match than 9:1 ununs – this means quieter noise levels and stronger signals so you can hear distance stations easier.