50:200 ohm (4:1) McCoy Ladder Line/Antenna Tuner HF Balun Kit - 1500 watt PEP, 3-31 MHz
Model BA-4-1500 4:1 Balun Kit
Purpose. This kit is designed to convert from coaxial cable to ladder line at 1500 watts PEP 1.8 to 30 MHz when used with an antenna tuner. It provides conversion from unbalanced coax to balanced ladder line and gives a 4:1 impedance step-down to reduce impedance seen by the coax, allowing the tuner to easily match the antenna. Based upon the classic “McCoy” antenna tuner Ruthroff balun used for over 60 years!
Typical Impedance transformations are shown in the image below: