You need to install an AC line filter to reduce radio frequency noise heard in your station equipment. What type of frequency response should it have?

AC power operates at a very low frequency, typically 60 Hz in North America. Radio frequency (RF) noise, on the other hand, consists of much higher frequencies, usually in the hundreds of kilohertz or into the megahertz range. To allow the desired AC power to pass through to your equipment while blocking the unwanted high-frequency RF noise, you must use a low-pass filter. This type of filter passes frequencies below a certain cutoff point and attenuates everything above it. Using a high-pass filter would do the exact opposite, blocking your power and passing the noise. Band-pass or band-reject filters are unnecessary for this application, as you only need a simple cutoff between the very low AC frequency and the high RF noise.