Lieben-Reisz Relay valve, electrode support broken, (RMW/B15 - McVitie Weston number), by Telefunken, 1913. Presented to McVitie Weston by the Director of the Reichpost Museum Berlin, August 1938. Marked SS V 28 Nr. 2476. Scales marked above grid for setting height of dark space. An unused specimen. 320mm long.
This Lieben-Reisz Relay valve is a very rare early commercial relay valve made by the Lieben Consortium at the AEG / Telefunken works in Berlin in 1913. The Lieben-Reisz relay valve is named after its co-inventors Austrian electrical engineers Robert von Lieben and Eugen Reisz. Lieben-Reisz Relay valves were used for telephone and radio amplification from 1913 through the First World War and production continued until 1920. It was the first electronic valve used for the transmission of speech by radio-telephony when it was used by Alexander Meissner in his historic radiotelephone experiment, transmitting voice signals 23 miles (36 km) from Berlin to Nauen, Germany in 1913.