Which statement best describes the function of a jack box in S/P systems?

• A. It is a weatherproof enclosure that houses jack outlets connected to S/P lines.
• B. It is a portable speaker.
• C. It is a power supply unit.
• D. It is a digital router.

Answer: (A)

In S/P systems, the jack box acts as a rugged, weatherproof enclosure that houses jack outlets wired to the sound-powered lines. It serves as the passive interface where handsets or cables are plugged into the S/P network, protecting the connections from moisture and damage while providing convenient access points distributed around the ship or area. Since sound-powered systems rely on the operator’s voice energy rather than electrical power, the jack box simply routes andterminates the lines; it is not a speaker, a power supply, or a router. That is why this description best fits its function.