On 1/20/2020 2:28 PM, Richard (Rick) Karlquist wrote:
In most cases, line noise is a repeating function with a frequency of 50 or 60 Hz. To make an effective noise blanker in a contest, you simply have to make a filter that only responds to harmonics of the line frequency and then generate the inverse function from a 50 or 60 Hz line clock.
Unfortunately, that's too simple. For effective cancellation, that inverse function must be precisely in phase (degrees, not polarity) and equal in amplitude at each harmonic frequency.
73, Jim K9YC _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
