Which of the following is NOT a main element of a Tactical Communications System?

The correct choice is information dissemination, as it is not considered a main element of a Tactical Communications System. A Tactical Communications System focuses on the core components that facilitate the transmission and reception of information, ensuring effective communication in various operational environments.

Transmission equipment is essential, as it is responsible for sending signals through various media. Reception equipment complements this by receiving the transmitted signals, enabling the communication processes. Processing equipment plays a vital role as well, as it manages and converts the received signals into understandable formats for further analysis or distribution.

Information dissemination, while an important aspect of communication in broader contexts, is more of a process or outcome rather than a foundational element of the tactical communication system itself. It involves the distribution of information after it has been transmitted and processed, thus making it a step that occurs after the main communication functions have taken place.