Mitigation of Radio Noise from External Sources at Radio Receiving Sites
As a result of the RFI post in the blog a few days ago, a fellow ham sent me a link to this document, (which is in the public domain), and suggested I look at the pdf for help in tracking down the RFI at my home QTH. This document strikes me as one of the nicer items I have seen over the past few years dealing with RFI and how to deal with it. This document covers all aspects of Power Line Generated noise. It also covers some basic RFI location techniques. This book starts with a background and general approach chapter, and progresses forward in a clear and easy to read process, showing you how and where to look for RFI. Here is abrief excerpt:
EXCERPT:
The noise floor of a typical HF receiver is about –130 dBm for a 3-kHz bandwidth. This
indicates that the broadband dynamic range of components in the RF path from the antenna to a
receiver, and in the front-end portion of a receiver or noise instrumentation, must be about 100
dB for the daytime measurement of noise at a receiving site. A broadband dynamic range of
about 140 dB is required to ensure that nighttime noise data will not be contaminated by intermodulation products or inter-modulation noise generated by components in the RF path between
the antenna and the receiver. Alternatively, filters can be used to reduce the level of the
broadcast band signals. Daytime noise measurements can usually be made by the careful use of
conventional instrumentation. While some care must be made to ensure that instrumentation has
sufficient dynamic range to handle the daytime signal power, much greater care must be taken to
cope with the increased nighttime signal power.
Click below for this free book:
The Mitigation of Radio Noise from External Sources at Radio Receiving Sites
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