FREQUENCY MODULATION in general needs no introduction to the man who is interested in radio communication, no matter how remotely - he hears about it and sees references to it daily - it is literally thrust upon him from every side.
Because of its comparatively recent entrance into the communication picture, only a relatively few books about f.m. have appeared, and these have been introductory in nature for the most part.
Naturally when something new is brought out, numerous questions arise in the mind of every technically inclined man as to how and why it functions and how it can be employed.
This book is intended to answer as completely as possible those questions about f.m., and material has been included which hitherto has not been published.
Due to the importance that f.m. has assumed within the last decade we have incorporated in this book those basic principles underlying the operation of the complete f-m transmitter as well as the receiver, the discussion of transmitters embracing both the narrow-band and wide-band types that are being manufactured today for service in many different fields. Here both direct f-m and indirect f-m (p-m) transmitters are considered with all the essential theory necessary for a complete understanding of f-m and p-m transmission.
In order that the f-m picture may be complete, the subject of both transmitting and receiving antennas is covered and then the various types of receivers, their functioning and servicing. In short, f.m. is considered from the point in the transmitter where it first becomes a modula ted signal until it is translated into sound energy by the loudspeaker in the receiver.