Transistorized Binary Pulse Regenerator

Long distance communication using digital transmission is not new but was used by man in his earliest communication system. In fact, his first successful electrical system, the telegraph, made use of binary pulse codes. It was not until the invention of the telephone that the emphasis was shifted from the digital to carrier and voice systems. During recent years the development of new electronic devices and techniques have brought digital transmission into the picture again, and it now seems possible to use it not only for telephony but for television as well. Future systems will probably make use of the binary code, this choice being dictated by circuit simplicity and performance. The fundamental requirement for perfect binary transmission is to be able to detect the presence or absence of a pulse in each of a regular set of discrete time intervals. From this requirement the principal advantages of such a system may be tabulated. First, a pulse can be recognized in the presence of large amounts of interference. Second, when a pulse is recognized it can be faithfully regenerated, suppressing the effect of the interfering noise to any desired degree. Third, simple high-efficiency non-linear devices such as multivibrators or blocking oscillators can be used to regenerate the pulses. The great disadvantage, 1059