Throghout this book, figures have been used that show actual data plotted on an FFT spectrum analyzer. The presentation of these plots could have been handled in one of two ways:

The data could have been displayed with only enough notation to reinforce the point being made in the text. If this had been done, the reader looking at the data would have been left with the uncomfortable feeling that there was valuable information resident in each plot which could not be retrieved because of the insufficient notation. The resultant anguish might have caused come readers to totally miss the point of the figure.

If, on the other hand, full notation was included with each plot, the more casual or inexperienced reader might lose the point of the plot amidst vast amounts of irrelevant notation and data. This reader might soon give up trying to understand the spectral plots.

Upon serious consideration, it was decided to add this appendix to the book to explain how one reads the spectral plots. In this way, the data seeker can properly look at the data while the searcher of concepts can know which pieces of information contained in the plots are not relevant.

It should be noted at this point that each manufacturer of spectrum analyzers tends to use different notation on their plots. The good news is that, once the technician has mastered reading the plots of any spectrum analyzer or monitoring device, it is an easy matter to figure out the...