Survey of Man-Made Electrical Noise Affecting Radio Broadcasting

摘要

The document provides the results of a man-made noise survey designed to investigate levels of unintentionally generated noise in the New York City - New Jersey metropolitan area. Measurements were obtained and graphically presented for three frequencies: high frequency (HF) at approximately 20 MHz, very high frequency (VHF) at approximately 109 MHz, and ultra high frequency (UHF) at 800 MHz. Exact frequencies were determined by the absence of intentionally generated signals around the given frequencies. The noise parameters measured were true root-mean-square (rms) and weighed rms voltage from the detector output of an amplitude modulated receiver. The study concluded that automobile ignition systems are the chief sources of noise, at least in the United States of America. Power lines and electrical rotating machinery also contributed significantly. (Author)