Talking valves and V2 rocket radio control systems

This discussion brings together Dieter Beikirch and Robert J Dalby for an informal look at the development of German military electronics in the years leading up to and during the Second World War. The conversation begins with the evolution of the robust and compact German service valves in the mid-1930s, including the widespread use of the P2000 pentode and the introduction of the EF-14 in 1939. The technical discussion is set against the wider strategic backdrop, including the influence of Adolf Hitler and his role in delaying key areas of electronic development — most notably the decision to deprioritise centimetric radar, in contrast to British advances using the magnetron. From there, the focus shifts to the A4 / V2 rocket. The discussion examines the Honnef radio receiver used in engine cut-off, before moving on to the far more complex and still somewhat enigmatic Mischgerät – the analogue control amplifier responsible for the V2's stabilisation and control. Using a detailed schematic, we explore the internal structure of the Mischgerät, noting the apparently familiar arrangement of components – in places resembling conventional valve amplifier circuits — alongside the deeper, less obvious control logic embedded within the design. A key theme is the difficulty faced by Allied analysts, who, despite having access to the circuitry, were unable to fully understand its function until long after the war. The discussion highlights an important point: that even a complete schematic does not necessarily reveal the underlying intent of a system. Without insight into the designer’s objectives, the true nature of the control solution can remain hidden in plain sight. This video forms part of the Deutsche Avionik series, drawing on Dieter Beikirch’s extensive collection of original German WWII radio technology used by the Luftwaffe and Kriegsmarine. We would also like to extend our sincere thanks to Sabine Beikirch for her invaluable assistance during this discussion, helping to bridge the gap between Dieter’s English and Robert’s German (or rather lack thereof), and making this exchange possible. Video produced by Astronomy and Nature TV 2026 all rights reserved