A more serious title for this chapter could have been The reverse engineering of phase noise. When a computer hacker gets into trouble, he or she tackles the root of the problem, by reading the source code, patching the kernel, and recompiling the system rather than just rebooting the machine. There are at least two serious reasons for choosing such a radical approach. The first reason is to acquire a deeper understanding of the system being investigated, i.e., to “solve the puzzle,” and the self-confidence that goes along with this. Such an understanding ultimately results in an improvement in the performance and the reliability of the entire system. The second reason is that a radical approach is ultimately the simplest and perhaps the only legal way to solve the problem. So one should solve, rather than find a provisional remedy. This book is far less ambitious. Nonetheless, having been frustrated for years by the insufficient technical documentation of oscillators, one begins to realize that there is a lot of information written between the lines in invisible ink. Yet it is not that invisible! By hacking the technical information, we can deduce – or at least guess – the relevant parameters, such as P0, Q, fL, the amplifier's 1/f noise, etc. The need to guess the internal technology is a source of difficulty, inconsistency, and frustration. How to cope with this is part of the message addressed to the reader.