N6OL Powerline QRM Monitor

Introduction

The N6OL Powerline QRM Monitor grew out of a quick and dirty hack to continually monitor QRM generated by my local electrical utility company in my neighborhood, in the hope that I could find some pattern to whether the noise was present at any given time of day, or some correlation with weather conditions, etc.

What this monitor can do

The monitor can help you confirm that a noise you're receiving is in fact characteristic of powerline QRM, versus something else. It is a fairly accurate time-domain analysis tool that looks for the typical 2x line-frequency impulse noise generated by powerline arc noise. (Twice the utility frequency because the arc is typically from both the positive and negative peaks in a full cycle.)

It will log your average QRM signal, the estimated noise floor level, produce minute-by-minute charts, and summary charts giving the noise probability at different times of day over the last 7 days, 30 days, and full data set. Weather data can be optionally included in the logs.

Optionally it can auto-record .wav files of detected events with configurable limits and publish your logs and charts to a web server. It can also render the analysis of .wav files to video. It can also analyze .wav files that were created outside the program in real-time, as though they were being received from the radio, however, the absolute levels reported from this type of analysis are not guaranteed to be accurate.

What this monitor cannot do

The monitor cannot tell you the source of the QRM by itself, though it can give you an idea about when you should go direction-finding to locate it.

It cannot detect other types of QRM: it's limited to detecting impulse noise at regular intervals.

It cannot tell you if the noise source you're receiving comes from your utility company's equipment or something producing impulse noise in your own home or the home of a neighbor.

Getting started

To get started, head over to the Getting Started tutorial.