What equipment provides high frequency voltages for transmitting voice communication on high voltage transmission circuits?

The choice of carrier equipment is correct because it specifically refers to the technology designed to transmit voice signals over high voltage transmission lines. Carrier equipment utilizes high-frequency voltages modulated onto the power lines, enabling audio communication over significant distances while ensuring minimal interference with the primary electrical power flow.

This technology effectively combines voice and data transmission, allowing utility companies to communicate efficiently through their existing infrastructure without the need for separate lines. Carrier equipment is vital for maintaining communication in operational environments, such as during outages or maintenance work, where coordination is crucial.

Other options do not fulfill the requirement of transmitting voice communication over high voltage transmission systems. Signal converters typically modify signal formats rather than transmit voice. Telephone lines are not used over high voltage circuits; they operate independently for voice communication. Routers are used in data networks to direct internet traffic, which is distinct from transmitting voice over high voltage power lines.