TBX-6 Transceiver
1941
The navy model TBX-6 equipment is desgined to meet the paramount requirement of providing satisfactory communication between similar equipments installed ashore, aboard, ship, or in small baots, and between such equipments and other units of the naval communication system at ranges of approximately 30 miles for cw transmission and 15 miles for phone transmission.
This is the famous equipment used by Navajos code talkers.