Diagrams to explain the operation of linear and nonlinear engineering systems

The author taught a basic course in electronic communications at New York Technical College. The class consisted of students in electrical engineering technology, who, for the most part, are "mathematically challenged". To reach these students, mathematical equations need to be reduced to a minimum and to be replaced by diagrams and physical reasoning. In this spirit, the author began to develop a series of diagrams to explain the operation of AM and FM transmitters and receivers.