Experience the American Journey through our country's visual heritage in this historical recording provided by the National Archives of the United States. Instructional Film: describes the radio transmitter-receiver unit used during World War II. Explains compactness and ease of concealment, and outlines operations in detail: selection of electrical outlet, battery, or combination of both as power unit; antenna, assembly parts, installation, frequency determination and receiver operation; parts installation, attachment of crystal equipment and transmitter operation. From the Office of Strategic Services. This historical recording from the National Archives may contain variations in audio and video quality based on the limitations of the original source material. The content summary for this DVD is adapted from an historical description provided by the government agency or donor at the time of production release. This product is manufactured on demand using DVD-R recordable media. Amazon.com's standard return policy will apply.