Wireless On the Move: the HF versus VHF saga in WW2.

by Dr Brian Austin

In this thought-provoking article, Dr Brian Austin revisits the British Army’s wartime communications strategy, challenging long-held assumptions about the dominance of HF over VHF. Drawing on historical records and technical analysis, he argues that institutional bias and flawed scientific advice—most notably from Sir Edward Appleton—led to costly operational shortcomings, particularly at Arnhem. Through the lens of figures like Walter Gill and the overlooked potential of VHF, this piece offers a reinterpretation of a pivotal chapter in military communications history.

Introduction

British Army mobile radio communications throughout the Second World War took place, almost without exception, at the lower end of the HF (3 – 30 MHz) spectrum with some wireless sets even using frequencies lower than that in what is called the medium frequency (MF) band. This turned out to be a fateful decision when viewed in hindsight and particularly since both its major ally, the Americans, and its German enemy had shown how effective the much higher frequencies, at VHF (30 – 300 MHz), could be. It was also a very costly decision because of the serious communication problems that plagued many of the Army’s major operations throughout the war and none more so than at Arnhem in September 1944.

Following the establishment of the Royal Corps of Signals in 1920 various signals branches came into being with one of them being the Signals Experimental Establishment (S.E.E.). Its purpose was to provide technical advice to the Corps as well as to design and test all the prototype equipment developed for the Army. Since the period in question was little more than twenty years after the miracle of wireless communications had first stunned the world following Marconi’s spanning of the Atlantic in 1901, it will be appreciated that the technology available was what one might describe as primitive. Its greatest shortcoming was the frequency range over which it was possible to generate sufficient radiated power to make communications feasible. And the limiting factor was the technology of the thermionic valves then coming into service. Thus, it was that the British military acquired wireless equipment that operated at the lower end of the HF spectrum with the natural consequence of that being the relatively long wavelengths involved.  To put this into context we should appreciate that at a frequency of 10 MHz the wavelength is 30 m whereas, at a decade lower, of 1 MHz the wavelength is 300 m. And, of course, it is the dimension of the antenna - the most vital element in the communications chain – that is related directly and most importantly to the wavelength of operation.  As will become clear below, the length of an antenna determines its efficiency and hence its gain and to be able to radiate effectively an antenna either has to be naturally resonant or it must be forced to resonate by means of external circuitry. The ultimate effectiveness of the communications system is then a direct function of the performance of the antenna. Almost without exception every wireless set used by the mobile Army during WW2 operated with highly inefficient antennas as a consequence of their lengths being very short in terms of wavelengths.

Link to full article.