Final answer:
The TA-312/PT telephone has a typical range of about 22 miles, which can vary depending on several factors such as wire type, environmental conditions, and equipment status.
Step-by-step explanation:
The TA-312/PT telephone is a field communication device that was widely used for voice communications by the United States military. It is designed to operate in various field conditions. The range of the TA-312/PT without using any additional equipment (like line amplifiers) is typically around 22 miles (35 kilometers) when using standard field wire (WD-1/TT). This range can be affected by the type of wire used, environmental conditions, and the maintenance status of the equipment.