Picture from the radio room on board the Graf Zeppelin, 1930. It was manned with telegraph operators from Deutsche Betriebsgesellschaft für drathlose Telegraphie, DEBEG. Photo: Archiv der Luftschiffbau Zeppelin GmbH. 

The Largest Transceiver in the Air

The radio equipment on board Graf Zeppelin was the so far largest transceiver installed in an aircraft. It was manned by three radio telegraphers who were in contact with stations on the ground and ships at sea via radio waves to the benefit of security, passengers, and newspaper readers all over the world. Power sources, transmitters, receivers, and aerials constituted a temporarily culmination in the rapid development of "the wireless".

Important Messages

The principal task of the radio telegraphers was to enable the crew on the bridge to steer the airship safely through the air to the destination. They carried out radio direction meaning that via known positions of stations on the ground or ocean-going steamers they were able to determine the position of the airship. For that purpose they used a directional aerial covered by a cupola which was placed underneath the gondola of the airship. Moreover, they had to pick up weather reports continuously. The landing of the airship was to be announced in due course via radio telegrams leaving enough time to make the necessary provisions on the ground.

Last, but not least telegrams to and from passengers on board had to be handled. This applied to as well private telegrams as news from reporters. 484 private telegrams with totally 10,454 words and 160 press telegrams with totally 8,395 words were handled during Graf Zeppelin's first flight to America and back in 1928. In addition to this came the communications concerning navigation and weather reports.
 

"Head" of DEBEG telegram form for use in the airborne telegraph stations on board the airships. 

Wireless Technology

Parts of the radio-technical installations as well as their attributes were very impressive. The primary aerial consisted of two wires each 120 metres long which were both lowered - while the airship was moving - by means of an electric motor or by hand power so that they described a soft curve below the airship. During the round-the-world flight in 1929 they managed at very regular intervals in the night hours to communicate on short-wave with stations at a distance of up to 6,000 kilometres.

The transceivers on board the airships from Luftschiffbau Zeppelin GmbH were produced by Telefunken. Spark transmitters were used at first, later replaced by thermionic valve transmitters, and a number of other radio-technological improvements were currently added.