Deflating British Radar Myths of World War II

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Birth of Radar Memorial at the site of first successful RDR (radio detection and ranging) experiments by Robert Watson-Watt and Arnold Wilkins near Daventry, 26 February 1935. At the time, there was no plaque and no publicity; the first British radar experiments were so secret that only three people witnessed them on the ground. What is not obvious is the fact that this British effort took place two years after the development of a practical radar in Germany .
[kintalk, via Wikimedia commons]

British and Allied memoirs and histories have contributed to the rise of three myths concerning the discovery and employment of radar. These myths are as follows. The first myth is that Sir Robert Watson-Watt is the father and sole inventor of radar. The second is that Germany’s discovery and realization of radar’s military worth occurred after 1940 following exposure to British systems. The third myth gives radar the pivotal role in the defeat of the Luftwaffe in the Battle of Britain. To deflate these myths the origin of radar is traced from James Maxwell’s discovery of radio waves to early radar theorists and inventors. Their role in the story of radar illuminates and contributes to the deflation of the radar myths. Both the rebirth of the Luftwaffe and evolution of the RAF during the 1920’s and 1930’s shows how each service independently arrived at the development of radar technology for different reasons. In 1939 Germany possessed some of the world’s best and most enduring radar designs, as well as essential navigation and bombing aids. England’s Chain Home radar was a dead end technology with serious shortcomings, but was skilfully melded to an innovative command and control system. The illumination of German radar achievements and a balanced analysis of British defensive systems essentially deflates the radar myths.

Wizard War

“This was a secret war, whose battles were lost or won unknown to the public; and only with difficulty is it comprehended, even now, by those outside the small high scientific circles concerned. No such warfare had ever been waged by mortal men.”
Winston Churchill

With those words Winston Churchill immortalized the British and Allied scientific war effort against the German enemy, giving credence to several long-held myths about superior and innovative British radar techniques. Post-war histories and autobiographies have concentrated on what the Allied forces did right against the Germans and tend to favourably promote the success of government programs and their administrators. The sheer destruction, defeat, and partition of post-war Germany has made the other side of the story harder to discover and attribute. In the late forties, the world was not in a mood to praise German scientists and technological innovation, with the sole exception being the German rocket scientists. From the wealth of World War II histories and accounts, a theme has evolved and received support over the years concerning British radar at the beginning of the conflict. These themes, essentially myths, concerning radar are the following.

  1. The British invented radar and that scientist, Sir Watson-Watt, was the father of this technology.
  2. The Germans did not have pre-war radar, and failed to grasp the importance of this technology. The Germans only developed radar in response to their defeat in the skies over Britain, or from stolen British plans and equipment.
  3. The British radar system played a unique and pivotal role in the success of the Battle of Britain.

In order to deflate these myths to their proper size, this material will be organized into four sections. The first section will explain some basic radio theory and history in warfare. Section two will cover the development of German Luftwaffe defensive strategies and then the existence of German radar. The third section will do the same analysis of the British approach. In section four, the radar myths will be re-examined in light of the previous discussions. The focus of this research is on pre-war Germany and Britain; comparing and contrasting tactics and technology that existed prior to hostilities.

The Technology of Radio

The theories and scientific insights into the technology of radar became available to the world in 1887 when Heinrich Hertz in Germany discovered the existence of radio waves. The scientific journey leading to this discovery started with James C. Maxwell’s Dynamical Theory of the Electromagnetic Field developed around the 1850’s which theorized that there existed invisible rays, not seen by the human eye, created by oscillatory electric currents. The search for other types of radiation was a fierce scientific competition leading to discovery of Roentgen’s X-rays and culminated with Hertz’s discovery of the electromagnetic spectrum.

Hertz experimented with electric sparks, and in 1888 he found that a spark jumping from two metal spheres in a loop of wire would cause another spark to jump between two other metal spheres in a similar loop, even with this loop being meters away. This simple effect had tremendous implications and gave an alternative to the wire-linked telegraph, the wireless.

In less than a decade later Guglielmo Marconi obtained a British patent for his wireless design, and stations were transmitting across the English Channel in 1898. The needs of the British empire for a means of global communications fuelled and accelerated the use of the new wireless technology. This invention was immediately duplicated or rediscovered throughout the world. Notably in 1909 both a German named Karl F. Braun and Marconi shared the Nobel Prize for their work in the area of radio.

Rival commercial companies arose from their work, with the Marconi Company in Britain and Telefunken in Germany. They supplied equally capable technology to their countries’ military and exported it to others.

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92 Comments | Add New

By Ewan S Fallon  |  2013-03-28 at 06:47  |  permalink

Did the major forget about this:

The story begins in September 1940 with the arrival in Washington of a team of British scientists bearing England’s most closely guarded technological secrets, among them the cavity magnetron, a revolutionary new source of microwave energy that was to pave the way for radar systems small enough to fit on planes and ships. The magnetron’s arrival triggered the most dramatic mobilization of science in history as America’s top scientists enlisted in the “war within the war” to convert the British invention into a potent military weapon.

By ari  |  2016-01-17 at 15:12  |  permalink

The Cavity magnetron was invented by Germans Hans Erich (Eric) Hollmann invents the cavity magnetron in 1935 ,filed a patent in 1936 long before the Brits and granted a patent in 1938 ..Birmingham university scientists simply worked on this.. Hitler didn’t support the Project because German military considered the frequency drift of Hollman’s device to be undesirable, and based their radar systems on the klystron instead but klystrons could not at that time achieve the high power output that magnetrons eventually reached.Good for the allies and bad for Germans.
The question why it was brought to the US by Tizard was not without reason, a brilliant American inventor Percy Spencer had invented a revolutionary method of how to manufacture it in huge numbers.
I quote: At that time, magnetrons were used to generate the microwave radio signals that are the core mechanism of radar, and they were being made at the rate of 17 per day at Raytheon. While working there, Spencer developed a more efficient way to manufacture them, by punching out and soldering together magnetron parts, rather than using machined parts. It also saw Spencer’s staff rise from 15 employees to 5,000 over the course of the next few years. His improvements were among those that increased magnetron production to 2,600 per day.

That was the main reason why it was brought to the US, to the Radiation Labs of MIT…This is the real history, maybe there is another version ( British version ) but as far as I know this is the universally accepted version.

By Alex  |  2016-02-10 at 21:00  |  permalink

What you say is essentially correct. However the bootstrapped cavity magnetron by Randall and Boot overcame the problems you mention. ie low power and frequency drift. This gave the allies significant advantage. Credit where it is due.

By Alex  |  2016-02-10 at 21:29  |  permalink

More magnetron details here:

By alex  |  2013-09-11 at 07:55  |  permalink

Further to previous, pulsed transmission radar actually existed from 1926 onwards. Physicist, Edward Victor Appleton, used frequency modulation radar to accurately measure the ionosphere in 1924. This was the first time that an object was measured by radio location. He repeated this experiment in 1925 using directional antennae. Also in 1925, Merle Tuve and Gregory Breit invented the ionosonde in the USA. In 1926, Edward Victor Appleton adapted the ionosonde for use with the oscilloscope developed by Robert Watson Watt and his own pulsed method of measurement. He used the resulting pulsed transmission radar to measure the ionosphere.

Edward Victor Appleton was elected Vice-President of the American Institute of Radio Engineers in 1932.

By Jonathan Walker  |  2015-07-04 at 08:58  |  permalink

Hi Alex,

from your post it sounds as though Appleton was an American.

He was a Yorkshireman (Englishman) and he was not President but “Foreign Honorary Member of the American Academy of Arts and Sciences”.[

By Jonathan Walker  |  2015-07-04 at 09:01  |  permalink

Sorry meant to say “he was also elected”.

By Alex  |  2016-02-10 at 20:42  |  permalink

The point I was making was that Appleton took his technology to the US.
He was elected Vice president according to the following site:

By Dick McCue  |  2014-05-15 at 14:39  |  permalink

The article does indeed contain some inaccuracies, but so do many of the commentary.

Dr Hans Hollmann patented-secretly- the cavity magnetron in Germany during 1935. At the time Hollmann was on the developmental team of the prototype Seetakt radar then being tested. GEMA engineers dropped the magnetron from the Seetakt design by 1936 because the natural instabilities of the magnetron did not work with Seetakt’s sophisticated system of using a master modulation to regulate the timing of pulses and to measure fine range by phase differential.

The Japanese also discovered the cavity magnetron independently. It was used in the 10cm naval radars operational from mid 1941. The Japanese did not discover strapping, however, and this limited the power output of their centimetric radars.

By alex  |  2015-03-30 at 14:25  |  permalink

The cavity magnetron I was referring to was the bootstrap cavity magnetron by Randall and Boot, 1940. It was this version that was high powered and gave the allies the advantage. I should have made this clear.

By Don  |  2015-07-19 at 11:38  |  permalink

More magnetron details here:

By Jonathan Walker  |  2014-05-25 at 08:58  |  permalink

I have not yet read your whole text but you mention the Wizard War, which is the title of an excellent book by Dr. R.V. Jones – English Title Most Secret War.

No one who has read this book or taken an interest in the technology of WW2 will have any doubt that the original Chain Home radar system was pretty crude – or that radar was developed more or less simultaneously in several countries.

The area where Britain led was the development of the system of communications and information appraisal that allowed Fighter Command to put its assets in the right place at the right time and otherwise use them rationally and economically.

This was because Britain started at an early stage to develop radar as the basis for air defence system, while their enemies were occupied with the offensive use of air power.

But as the war progressed, British innovations like the Cavity Magnetron and the Plan Position Indicator far outstripped developments on the German side, so that by the end of the War, overall British superiority was no myth.

By James Sutton  |  2014-09-06 at 17:40  |  permalink

Microwave radar gave a decisive advantage, and required three inventions to be workable – the cavity magnetron as stated previously; the NR89 reflex klystron (“Sutton tube” after Robert Sutton), for a tuneable local oscillator for the receiver; and a crystal detector. ref. “Metres to Microwaves” E.B.Callick. ISBN 0 86341 212 2

By Don Webber  |  2015-05-25 at 08:25  |  permalink

Sir Winston Churchill was quite open on the subject in 1948/9. In his history, The Second World War Volume 1; The Gathering Storm, he states in Chapter 9 that by 1939 “(t)he Germans…had developed a technically efficient radar system which was in some respects ahead of our own. What would have surprised them however was the extent to which we turned our discoveries to practical effect, and woven all into our general air defence system. In this we led the world, and it was operational efficiency rather than novelty of equipment that was the British achievement” (my italics).

By Don  |  2015-07-12 at 12:39  |  permalink

We did very well in the ’30s and throughout the war, but we must not claim more than we justly deserve: other countries were also working on radar independently. Sir Robert Watson-Watt was not the inventor of radar, as is commonly believed. That was a myth that, according to “Leaps in the Dark: The forging of scientific reputations” by John Waller (available from Amazon), was put about by Watson-Watt himself. Sadly, he does not come out of this very well.
In my view, the programme would have been better had it given equal (or greater) billing to the likes of Appleton, Taffy Bowen, Tizard and especially Arnold Wilkins. “It was Arnold Wilkins who suggested to his boss, Robert Watson Watt, that reflected radio waves might be used to detect aircraft, and his idea led to the initial steps in developing ground-to-air radar in the UK. Wilkins also provided all the theoretical calculations to back-up his idea of aircraft detection, and it was his lashed-up system that he used in the Daventry Experiment to demonstrate that his idea would work. With the Daventry experiment, Wilkins successfully detected an aircraft (up to eight miles away) by reflection of radio waves for the first time in history”. ( and and These and many others helped the RAF, enormously, to win the Battle of Britain which would almost certainly have been lost otherwise. Later on there were Randall, Boot and Sayers of Birmingham University whose development and improvement of the cavity magnetron (patented in Germany in 1935 by H.E. Hollmann) was the great spur which, with the indispensable help of the Americans after the so-called Tizard Mission to the US, moved the allied radar effort on to greater things, eventually to help to win the war.

The post-war scientific “establishment” should probably have done more to gainsay W-W’s claim to be the father of radar, but Britain, having emerged from several years of war, was in no mood to acknowledge German achievements. Radar had a very long history before the second world war and was being independently developed in several countries including the USA and Germany. In fact Churchill in 1948/49 in his history The Second World War Volume 1; The Gathering Storm, states in Chapter 9 that by 1939 “(t)he Germans…had developed a technically efficient radar system which was in some respects ahead of our own. What would have surprised them however was the extent to which we turned our discoveries to practical effect, and woven all into our general air defence system. In this we led the world, and it was operational efficiency rather than novelty of equipment that was the British achievement”. We have Tizard to thank for that operational efficiency: look up the Biggin Hill experiment.

A good example of German technical superiority at the beginning of the war was the heavy cruiser, the Admiral Graf Spee, which used a sophisticated radar successfully against shipping in the Atlantic. In Dec. 1939 (note the date!), after heavy fighting during the Battle of the River Plate, the Admiral Graf Spee was severely damaged and the captain scuttled the ship in the neutral harbour off Montevideo, Uruguay. The ship sank in shallow water such that its radar antenna was still visible.” taken from

By Don  |  2015-07-20 at 06:26  |  permalink

Just for clarification, the “programme” I referred to was “Castles in the Sky” on BBC in 2014 and out on DVD now. The critique above is based on my critique on Amazon.

By Don  |  2015-08-27 at 19:04  |  permalink

Most importantly, I should have added Arnold Wilkins in the penultimate paragraph above. So where I said “The post-war scientific “establishment” should probably have done more to gainsay W-W’s claim to be the father of radar, but Britain, having emerged from several years of war, was in no mood to acknowledge German achievements” I should have added ” and Arnold Wilkins was too modest and, unlike W-W, too uninterested in self aggrandisement. So W-W got away with his ridiculous claims. Such a pity, because he was not unimportant in the history of radar.”

By dc  |  2014-09-03 at 22:24  |  permalink

The thing that confounded the Germans was the T-R cell which allowed radars to send receive using the same aerial. Every time they cracked one open the gas turned into a water droplet.

As mentioned previously it was the advent of the resonant cavity magnetron along with things like the T-R cell and the PPI which gave the allies a quantum leap in radar development.

Interesting to see the myth that the Germans didn’t have radar exposed.

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