2:1 (100:50) Baluns are useful between 50 ohm coax and 100 ohm balanced lines for loops, cubical quads, log periodics and other antennas where the impedance at the end of the feedline is 100 ohms (1/2 wavelength feedline).
RFI/EMI Solutions from KHz to GHz
Purpose. The CMNF-TV is used to suppress RFI noise and common mode interference on the coaxial input line of satellite and cable TV receivers often caused by nearby transmitters
The filter is designed to have a high RF impedance to noise and interference from common mode currents on the outside of the coax braid while passing RF signal currents on the center conductor and inside of the coax braid to the antenna.
The effectiveness of the filter is dependent upon the amount of common mode noise encountered on the feed line. If your receive system has a large amount of common mode noise current then you should experience a reduction of common mode current which usually as heard as background noise level. Typical choking impedance is shown in the gallery picture.
Got Common Mode Noise? Not Sure - Find out now by clicking link below:
The filter was quite effective. Was surprised that it actually reduced the noise level more than the signal so S+N/N improved by 1.9 S units. Bill