SIGNAL: Sonya’s Wireless

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Signal Issue 64

Agent Sonya’s wireless: fact, fiction, fantasy and fable

Brian Austin G0GSF

Two recent articles [1,2] in Signal tell some of the story of the remarkable Soviet agent who plied her trade for almost twenty years, beginning in Shanghai and culminating in her sudden departure from England in 1950. In between, she operated under various names, familial as determined by her various marriages and her codename dictated by the secret nature of her work. For all of what follows, I shall refer to her by that nom de guerre. She was simply Sonya; though Sonia or even Sonja appear too, depending on which source you choose to cite. 

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Born Ursula Kuczynski in 1907 in Berlin to a wealthy left- wing  intellectual  family,  she  espoused  the  communist cause at an early age. Her older brother Jürgen became an economist of some repute and a prolific author in his field.  He  was  also  an  active  promoter  of  communist philosophy which he pursued, with vigour, after following his parents to London and a post at the LSE following Hitler’s rise to power. In late 1929, Ursula married Rudolf “Rudi” Hamburger, an architect. Work had dried up owing to the worldwide Depression but Rudi was offered a post designing office buildings in Shanghai. The young couple arrived  there  in  July  the  following  year  and,  not  long afterwards, Ursula joined the Chinese Communist Party. Her active promotion of the revolutionary cause in Berlin soon found an immediate outlet in Shanghai, the home of Chinese communism in a country ripe for revolution. Her career as a spy began when she met Richard Sorge, a German, dubbed by some as the most formidable spy in history [3]. And through Sorge she became aware of the part  played  by  radio  communications  in  the  spying business. 

If any aspect of espionage has been misunderstood and misrepresented, sometimes egregiously so, it is probably the  use  of  radio  or  wireless  communications  to  pass messages  between  spies  and  their  headquarters  or, equally, in the opposite direction.  Why this should be so is not hard to fathom. To most people, including most professional  historians,  the  transmission  of  messages ‘through the air’ without the intervention of wires is, at best, mysterious and, at worst, is something of a black art. Its technicalities are not understood at all and the technology to accomplish it requires, apparently, nothing more than a transmitter. That the author should have such a cynical view is, perhaps, best illustrated by the recent book written by Ben Macintyre [4]. The fact that it was a best-seller is certainly testament to Macintyre’s skill as a story-teller with his proven ability to write for a mass audience seeking titillation  as  well  as  a  good  yarn.  This  book  certainly contains both. But it falls down badly when it comes to the technology  of  wireless  communications.  And  it  is  this aspect that I intend to concentrate on here. All the other intriguing details, and there are many, of the ‘spying game’ will be left to the ever-expanding literature on the subject.

“On  the  nights  she  transmitted  to Moscow …”

Clandestine communication is a science as well as an art [5].  Sonya  herself  was  trained  in  Moscow.  At  the instigation  of  Sorge,  she  attended  the  Radio  Training

Laboratory  there  in  1933  where  she  learnt  the  art  of espionage and some of the technicalities of wireless. She was bright and was an excellent student because her heart was  undoubtedly  in  it.  She  also  displayed  an  above- average ability as a Morse code operator. Loyalty to her Soviet masters, and to their cause, had to be absolute and she signed up to it all with fervour. But it wasn’t a solitary activity; Sonya had assistance and assistants: all men. Her husband ”Rudi” Hamburger, though, was never more than a lukewarm communist and so she kept him in the dark. Sorge was the dominant figure and his radio expert was Max Clausen and Sonya absorbed much from him. There were  others  too  and  among  them  was  a  man  called Johann Patra who was to have a significant influence on her clandestine life and it’s at this point that the fantasy begins. Patra was highly intelligent but wholly uneducated, according  to  Sonya.  He  also  struggled  to  read  in  any language, though Macintyre informs us a while later that he  was  struggling  to  read  Hegel’s  Science  of  Logic. Remarkable, to say the least. More mundanely, he soon went “shopping for valves, rectifiers and wiring” with which to build a transmitter. How he went about selecting these components and their very important specific types, given his apparent lack of familiarity with the written word (except Hegelian),  is  not  explained.  One  has  to  assume  that Macintyre was quoting Sonya herself, now writing under the nom de plume of Ruth Werner, since he clearly makes liberal use of her memoir published as Sonjas Rapport, in German, in 1977 and then, as Sonya’s Report in 1991 [6]. And she published more too, in German, on this unfolding saga as listed among the references in [1].

Sonya  and  Patra  went  to  Mukden  in  Manchuria,  as instructed by the ‘Centre’, their headquarters in the Soviet capital. Mukden was occupied by the Japanese and their function  was  to  be  the  point  of  contact  between  the Chinese communist partisans and Moscow. It was Patra’s job to assemble the radio equipment from the components he had recently acquired. From [1] we learnt what the strange  “Hartley  transmitter  three-point  switch”,  as described  by  Sonya  in  her  1977  book,  actually  was. However,  Macintyre,  without  providing  such  technical niceties, called it a transmitter-receiver whereas the circuit diagram in [1] shows nothing more than a simple one- valve Hartley oscillator which would have functioned quite adequately as a QRP transmitter but it was certainly not a receiver. Of course, any transmitter without an antenna is useless and so Sonya climbed onto the roof of the house she’d found in Mukden to erect what she called a Fuchs aerial. This was a half wavelength of wire which was end-

fed, hence presenting a high impedance at that point and thus  necessitating  some  form  of  impedance transformation to a lower impedance transmission line, assuming such were used. Macintyre, needless to say, went into no such detail. But what is particularly important is that this is the only time in his book when any detail at all  is  provided  about  an  antenna.  Where  he  (and presumably she) mentioned it again it was simply a length of wire suspended from the roof of a house to a pole in the garden or secreted behind the panelling of a wooden wall. The assumption clearly being made is that an antenna is simply  a  length  of  wire  whose  dimensions  are  of  no consequence. 

While in Mukden, Sonya only transmitted at night to the GRU (Russian  Military Intelligence) receiving  station in Vladivostok, a distance of around 700 km. Both those facts are important because they involved the ionosphere, a subject  never  aired  by  Macintyre  (and  perhaps  not  by Sonya herself in her multi-volume tomes). None of her radio  activities  was  every  arbitrary:  she  will  only  have acted on instructions. But how they were conveyed to her wasn’t  revealed  anywhere.  As  we  know,  such  long- distance transmissions depend entirely on the ionosphere and particularly on its critical frequency and height at a given  time  and  geographical  location.  Those  features change diurnally, with the seasons and particularly over the approximate 11-year period of the sunspot cycle. We are  informed  that  she  used  one  of  two  agreed wavelengths, though it is far more useful, as we will see, to define them by their appropriate frequencies. Again, this underscores the need for detailed operating instructions in order to “keep her skeds”, as they are referred to in the radio operating trade. Such trivia are not mentioned in Macintyre’s best-seller.

We are led to believe that Sonya was busy at her radio at least  twice  a  week  and  always  in  the  early  hours. Messages consisted of information about partisan morale, Japanese  counter-insurgency  measures  as  well  as political and military intelligence. What never emerges is what radio receiver she used to make all this possible. Brief,  almost  glib,  comments  about  constructing transmitters  –  as  simple  as  they  were  –  were  never accompanied by any details of the receiver. Once again, the impression is gained that Macintyre never appreciated the significance of the receiver even though he frequently mentions her taking down “the fastest incoming signals without making a mistake”. Again, as with the antenna, such things were apparently mundane since every home had a radio receiver and, in those days, they required the inevitable piece of wire to a pole outside. Need anything more be said?  Well, yes. The receiver is by far the more complex  piece  of  apparatus  when  compared  with  the simple transmitters she and Patra constructed. Even had it been as simple as a regenerative detector followed by a single stage of audio amplification, the circuitry to achieve that and the method of yielding optimum performance, were far from trivial yet such details are simply ignored.  And then there’s the matter of operating both transmitter and receiver on the correct frequency.

 “She established a good connection on a frequency of 6.1182 MHz …”

This intriguing gem of information pops up almost in the middle of Macintyre’s account when Sonya was sitting up in bed and just about to press her transmitter into service

to  communicate  with  Moscow.  What  could  be  more convivial?  But  we  need  to  get  there  first  because  this happened when she was in Poland and with yet a few more transmitter-construction projects behind her.

The mission in Mukden ended suddenly. The Japanese had penetrated Sonya’s network. Centre ordered her to pack up and leave as soon as possible for Peking. So, they dug a hole and buried the radio. No more no less. On reaching Peking, Patra, as is the pattern in this racy saga, “gathered  parts  to  build  another  radio”  and  the  first message from Moscow told them to hide the transmitter and take four weeks leave. One can only presume that any technical details are but background noise to the average reader of these fast-paced works of fact-based fiction. But to  those  of  us  who  actually  have  an  interest  in  the technology  they  are  frustrating  and  infuriating  because what is really important is reduced to the level of the almost banal. After this period of holiday bliss “they reassembled the radio” and, again, the first message from the Centre ordered Sonya to make for Shanghai while Patra was to remain where he was. The fact that she was pregnant with his child (though she never told him) was of no interest to Moscow but it added much flesh to the evolving life story of Macintyre’s heroine.

Reunited with Rudi Hamburger, Sonya was informed by her masters in Moscow that she and Rudi, now evidently a committed communist himself, were soon to leave for Poland. Their role there would be to provide the radio communications  links  between  the  Polish  Communist Party, now driven underground, and Centre. The journey to Poland involved a detour to England to be reunited with the Kuczynski family whom she’d not seen for years. They were now well-established in London’s communist circles. MI5 were aware of Sonya’s arrival in England, though to them she was merely Ursula Hamburger neé Kuczynski of interest because of those family connections. Her skill as a radio constructor-cum-operator had not reached them. In view of her German passport, her length of stay was to be brief.

In January 1936 the Hamburgers reached Warsaw but were then sent on to Danzig. There she built a transmitter- receiver, no less. A revelation indeed but details about its electronic  components  and  such  trivia  were  clearly immaterial. This time the transmitter was hidden inside a gramophone  but  the  companion  receiver  escaped mention. And, needless to say, the bothersome piece of wire  going  somewhere  did  too.  An  element  of  reality, however, did crop up when one of her neighbours asked Sonya if she received interference on her radio – the one that  everyone  possessed.  That  sent  a  chill  down  the Hamburger spine because, according to the neighbour, it happened at night and her husband thought it may have been caused by someone transmitting nearby. Sonya had been  in  contact  with  Moscow  the  night  before.  A  new location  was  urgently  needed  and,  once  found,  the transmitter came back to life. Inevitably, after many nights of transmitting and receiving, Moscow’s next instruction was to tell her to move back to Poland (the reader will be aware of the changeable geography in that part of the world occasioned by Nazi and Soviet machinations). At this point, Sonya confessed to her Soviet controller that she felt inexperienced and did not know enough about advanced techniques in radio construction. She requested further  training.  In  the  same  technical  compound  in Moscow where she’d been trained previously, she began

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her course during which she operated a “sophisticated push-pull transmitter” as described in [1]. On completion she  was  informed  that  her  next  destination  would  be Switzerland.

Switzerland and further fables

Neutral  Switzerland,  with  its  long  common  border  with Germany, was the ideal place to gather intelligence on Hitler’s military build-up. Sonya’s task was to set herself up near Geneva, then make contact with the existing Soviet- sponsored  intelligence  network  in  the  country  and,  of course, construct another transmitter. She was also on her own: none of those ultra-masculine companions from her days  in  China  or  her  recent  convert-to-communism husband, who joined her in Poland, would be with her. Switzerland  was  to  be  Sonya’s  solo  performance. Following yet another brief detour via England, Sonya left Dover in September 1938 for Switzerland via France. 

She set herself up in a village overlooking Lake Geneva. Macintyre then informs us that “[A]t night, when everyone was asleep, Ursula constructed her transmitter-receiver from parts bought at hardware shops in Geneva, Vevey and Lausanne”. The parts he mentions are indeed curious: a keypad (he surely means a Morse key since keypads are of our modern age on laptops), an antenna with banana plugs(!)  plus  two  heavy  batteries  “each  the  size  of  a dictionary”. No mention at all of all the components that go to  make  up  transmitters  and  receivers  or,  indeed, transmitter-receivers. How did she obtain the resistors, the capacitors, the valves, the RF chokes, the switches and the  myriad  other  bits  and  pieces  needed  for  even  the simplest  transmitter  and  its  companion,  though  clearly much compromised, receiver? And, most importantly of all

–  a component never mentioned by Macintyre – where or how did she acquire the quartz crystals which determined the frequency on which her transmitter operated? Surely not in a hardware shop no matter how sophisticated such places may have been in pre-war Switzerland. Credibility is  put  under  some  strain  here.  Macintyre  only  ever mentioned the frequency on which she operated, a very precise value of 6.1182 MHz, in a single sentence in his book. Such significant detail was clearly not of concern to him whereas it would have been vital to her and to the Centre.  As  is  well  known,  achieving  such  frequency precision would have been impossible with a variable LC- oscillator  unless  Sonya  had  available  to  her  accurate means of measuring frequency and unless she had also taken considerable care in constructing such an oscillator in order to render it ultra-stable. At this point I should mention that we learnt previously, but only in passing, that she  had  constructed  frequency  meters  on  one  of  her courses in Moscow but we were not enlightened as to how she  went  about  calibrating  such  a  thing.  And,  finally, electronic hardware has to be housed in some suitable box or other container. That requires metalwork, or at least woodwork, both of which need tools – a workshop even – and, of course, connecting all those components together means soldering. There’s ne’er a mention of any such oddities  by  Macintyre  and,  presumably,  not  by  Sonya herself when she came to write her life story many years later.

On the woodworking front we learn that Sonya hid her assembled  equipment  in  a  built-in  wardrobe  behind  a wooden panel held in place by screws. She drilled two small holes in the panel through which she passed the

leads (to and from what is not revealed). This, we are informed,  enabled  her  to  use  the  transmitter  without removing  it  from  the  cupboard.  Surely  the  mysterious receiver  must  also  have  been  nearby  with  its  vitally important headphones since having a loudspeaker blaring out Morse code was probably not a good idea. But she did conceal  those  two  drilled  holes  with  plugs  made  to resemble  knots  in  the  wood.  So,  all  bases  were  well covered and, as noted above, she could sit up in bed while communicating with Moscow. Following the necessary call signs, the messages consisted of groups of five numbers each of which she had encyphered earlier. 

Then we have to contend with a fascinating flight of fancy. Remember  all  this is taking  place  in  September 1938. Sonya  was  “flooded  with  relief”  at  having  successfully passed  the  information  to  the  Centre  and,  being  “too pumped with adrenaline to sleep” she reached out and turned on her transistor (my italics) radio in order to listen to the BBC news bulletin. Since the transistor was only invented at the Bell Telephone Laboratory in New Jersey in 1947 one can only assume that our heroine, or her 21st century biographer, were blissfully unaware of that fact but it made for a good story, particularly as the news bulletin focused entirely on the signing by Neville Chamberlain, the British Prime Minister, of the Munich Agreement. Peace with Germany was in the air. This was a horrifying prospect for all right-thinking communists. But, as we know, it wasn’t to last.

The International Brigade and Sonya

Yet another man of much interest, especially to the British security  services,  entered  Sonya’s  world  of  wireless, espionage and much else early in 1939. He was a former member of the International Brigade of volunteers who had enlisted to fight against General Franco’s forces in Spain. Len Beurton had been instructed to make contact with her by  “Mrs  Lewis”  of  Hampstead  in  London.  Mrs  Lewis happened  to  be  Sonya’s  younger  sister  who  was  an avowed  apologist  for  and  active  supporter  of  the communist  movement  wherever  it  happened  to  be. Beurton’s  background  was  mysterious  but  should  not detain us here. It would, however, perplex both MI5 and MI6  as  the  years  unfolded.  His  function,  as  Sonya explained it to him, was to undertake dangerous work in Germany. Beurton’s face evidently lit up at this. He was also smitten by Sonya.

The signing of the Molotov-Ribbentrop Pact between the Soviet Union and Nazi Germany in August 1939 detonated a bomb under Sonya’s spying operation against Germany: Allies don’t spy on each other; well, not usually. But she still had a useful role to play in the interim while her future was being planned for her in Moscow. She should train Beurton  and  another  former  fighter  in  Spain,  one Alexander  Allan  Foote,  codenamed  Jim,  as  radio operators. Foote, also an Englishman, followed a similar route to Beurton’s, though a short while before, in order to reach  Sonya.  It  was  the  same  Mrs  Lewis  who  had interviewed him and then instructed him on what he was to do. Quite simply, he was to attend a designated meeting place in Geneva, at a very specific time, while holding the correct  object  in  his  hand  and  then  responding  to  a particular question, asked by a mysterious woman, with a very specific answer. All good spycraft, of course. Foote was also told to “read up about wireless technology”. He clearly read well for, in no time, we’re informed that he was

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building  transmitters.  And  he  took  over  all  Sonya’s clandestine duties in Geneva, becoming the Centre’s chief radio operator when the time came for her to leave for her new destination: England.

Readers must excuse the detour here in order to expose some of Sonya’s private life. She and Hamburger were divorced  late  in  1939  based  on  perjurious  evidence provided willingly by Foote. In February 1940, she married Beurton  but  not  before  she’d  proposed  to  Foote.  She needed a British passport if she was to be able to live in England – as was Centre’s intention – and to get one she needed a British husband, however contrived. But Foote backed out for reasons we won’t go into, so she turned to Beurton. He agreed. And soon thereafter he excavated a hole  in  the  garden  into  which  they  buried  Sonya’s transmitter  as  the  attention  of  the  Swiss  authorities became ever closer. 

The saga of her passport caused consternation in England 

–  well, in MI5 at least. Beurton had already attracted their attention  and  was  on  a  black  list  of  communist sympathisers where his name appeared as Fenton. Now, his actual name was to be linked to a former Kuczynski and her world of London’s communists. However, MI5’s bureaucratic bungling failed to stop Sonya acquiring the prized document and she duly arrived, in Liverpool, with her two children (but without her new husband) in February 1941. Her immediate destination was Oxford because her parents had recently moved there from London. But it’s at this point that the conspiracy theorists begin to have a field day and none more so than another well-known writer of the spy genre, the late Chapman Pincher. In his sizeable 1984  book  Too  Secret  Too  Long  Pincher  asserts categorically that MI5’s Director General between 1956 and 1965, Sir Roger Hollis, was a Soviet agent. During the war it so happened that Hollis was based close to Oxford at Blenheim Palace and lived within half a mile of Sonya’s father. Pincher went into overdrive and concocted what to some was a very believable story that Hollis was not only a  Soviet  mole  but  that  his  collaborator  was  Sonya. Needless to say, when such accusations were made many years later, they (and Hollis himself) were subjected to intensive investigation. The finding was that there was no evidence  to  support  the  allegation  against  Hollis  but individuals  such  as  the  notorious  Peter  Wright  of Spycatcher fame dined out on it.

Oxford, Fuchs, Sonya and wireless

Sonya  and  her  two  children  moved  four  times  in  four months  after  reaching  Oxford.  Her  radio  operating activities came to a halt, but not permanently. In April 1941 she moved into a furnished house in Kidlington, five miles from the city. MI5 was watching her and intercepting her post. She made regular trips to London and waited on a particular street corner for her expected contact with her Soviet masters. Eventually, after a number of false starts one appeared. His name was Aptekar, whose cover was to act as chauffeur for an attaché at the Soviet Embassy. But to Sonya he was simply Sergei. He asked when she could bring her transmitter back to life. She said in twenty- four hours. Despite her life having seemingly turned upside down over the previous few months, she was apparently able to make contact with Moscow quite effortlessly by the very next  day.  Such remarkable insouciance,  technical

and otherwise, is staggering but it was happily accepted by Macintyre.

With the Soviets now fighting for survival against Hitler, Sonya’s  “intelligence”,  gleaned  from  among  the communist community in London, proved to be important and  it  soon  took  on  quite  earth-shattering  significance when she was introduced to Klaus Fuchs by her brother Jürgen. 

I shall not recount the Fuchs life story here. It resides among the literature and, indeed, the folk-lore of the atom bomb and its consequences for the world. Where Fuchs is important in this saga is that Sonya became his courier and go-between with Moscow. They first met in the centre of Birmingham in the late summer of 1942.  As they parted Fuchs handed her a file of some 85 pages of documents: the secrets of the development of the atom bomb. Her task was to get them to Moscow. Since they contained pages of mathematical equations and diagrams, as well as reams of text, there was no way such information could be sent by Morse code irrespective of the skill of the operator. Sonya used Sergei as the link man to the Soviet Embassy and from there the regular diplomatic pouch service did the rest. She and Fuchs continued to meet in rather more secluded  surroundings  in  the  fields  and  forests  near Banbury. There, while maintaining their anonymity, one to another, for reasons of ultra-security, they walked hand-in- hand to add an element of normality to their country stroll and along the way Fuchs would hand Sonya yet more information. She then used a ‘dead drop’ among the roots of a tree some way off the road to get them to Sergei. Much mythology seems to have been attached to this story and again I shall leave it to others to tell. On one of their regular encounters,  Sergei  handed  Sonya  a  miniature  camera with which to make microdot photographs. He also gave her “a small but powerful transmitter measuring just 6 by 8 inches”, so she told us. This borders on the ridiculous. Small and powerful are simply contradictory in this context. And, yet again, the vitally important radio receiver, as well as the means of powering them both, escaped a mention.  Between them Sonya and Macintyre, her trusting scribe, take most of their readers for granted, at the very least, because such technical details can so easily be ignored but those of us with an interest in such things do bridle!

However, we must assume that Sonya didn’t invent this story,  she  just  attenuated  it.  The  Soviets  did  have  a miniature transmitter and it had its companion receiver and they were both powered by a third unit containing the necessary transformer, rectifier and smoothing circuitry. It went by the name of Tensor or Tenzor (Figure 1) and came into service in 1942, so Sonya may well have been one of its first satisfied customers. The Tensor Mk1 was actually  designed  in  the  USA  (hence  its  collection  of readily identifiable valves) but it was also manufactured near Moscow, no doubt an example of early American lend-lease? Judging by the available photographs, each of those three separate units was of the size mentioned by Sonya  so  yes,  she  may  well  have  had  a  miniature transmitter but it was not powerful since it used a single 6L6 as its class C amplifier and, as we all know, that would have produced an output of 10 watts or so across the lower HF frequencies. According to the Tensor specification, it operated between 3.7 and 14.3 MHz, under either VFO or crystal-control.  The  magical  quartz  crystal  eventually makes its appearance but no thanks to our scribes.

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Figure 1. The Mk1 Tensor. Left to right:  receiver-PSU-transmitter    

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The Tensor receiver used three 6J7 valves with the first two  functioning  as  the  RF  amplifier  and  regenerative detector  and  the  third  as  the  AF  amplifier  driving headphones. Whereas constructing such units was well within the capabilities of a competently-trained technician, which Sonya claimed to be, the nonchalance with which she mentions the production of her transmitter-receivers, almost at will, raises all the issues I referred to above. And shopping for the necessary components, by a woman with a  German  accent,  would  surely  have  raised  the  odd eyebrow in the hardware shops she said she patronised for that purpose.

Between 1941 and his departure for the USA in order to join  the  Manhattan  Project  in  August  1943,  Fuchs  is reported  by  Macintyre  to  have  transferred  “some 570 pages  of  copied  reports,  calculations,  drawings, formulae and diagrams …”, and much more, to the Soviet Union. All would have gone via Sonya’s courier to the embassy. Late in 1942 she, Len Beurton, who was now in England, and their children had moved once again. Their new accommodation was in Summertown near Oxford. It was a cottage in the luxurious property belonging to one of the pillars of society by the name of Laski. His brother was a friend of Sonya’s father. Soon after moving in, Sonya asked permission to erect an aerial between the roof of the building  and  one  of  the  stables.  The  Laskis  never suspected that it was anything other than for improving the medium  wave  reception.  Besides  Fuchs  and  his  more incidental messages, she also had many other sources of intelligence of interest to Moscow. According to Macintyre, they numbered at least a dozen spies and so, by the end of the year, Sonya was said to be transmitting to Moscow two or three times a week. This amount of radio activity, of the non-atomic variety, could not have gone unnoticed and it wasn’t. The Radio Security Service (RSS), a specialist branch  within  MI6,  was  well  aware  of  all  those transmissions  originating  from  the  vicinity  of  Oxford (Figure 2). As was their procedure, all the intercepted five- digit code groups were passed to the RSS Discrimination

Section for assessment and then onward to Bletchley Park for its attention. Macintyre affords the RSS just a single paragraph and concludes that the Soviet’s use of the “one- time  pad”  system  would  have  rendered  its  messages unbreakable. This is probably true but there is no doubt that radio direction-finding techniques would have been capable of obtaining an accurate ‘fix’ on the location of Sonya’s transmitter. If this was done (and it must surely have been) we do not know the outcome. If there is an explanation, it lies in some vault or archive somewhere and is yet to be revealed. For a very detailed and forensic examination  of  MI5  and  its  dilatory  performance, particularly in relation to wartime Soviet activity in England, the interested reader is referred to the book by Antony Percy [7].

Fuchs returned to England from the USA in June 1946. By then he had effectively given the secret of the atom bomb to the Soviet Union. Sonya had been the conduit until his 1943 departure for Los Alamos where an equally effective US-based team of spies had taken over that role.

Sonya and MI5

Soon after VE Day, Sonya moved to the village of Great Rollright (Figure 3) in the Cotswolds, north Oxfordshire. Her new home was called The Firs. It was conventionally fitted out for its time but, according to Macintyre, it lacked an electricity supply. From the point of view of wireless communications this fact it highly significant. It seems, though, not to have struck Macintyre at all since he only mentioned it in passing. Of its many attractions The Firs had a large locked cellar which was ideal for concealing illegal radio equipment and, so we are informed, Sonya’s transmitter was in constant use. 

One  can  only  ask  how  this  was  possible.  The  Tensor equipment, if indeed that’s what it was, required at least a couple of hundred volts (DC) on the anodes of the various valves  hence  a  suitable  mains  supply,  such  as  that supplied with the very Tensor equipment, was a key part

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And the mere fact that she seemed to be able to hide everything in a matter of minutes, whether in holes in the ground or behind a fern-covered rock in  a fence  post,  surely makes that extremely unlikely and therefore was worthy of comment from Macintyre. But there was none. And, needless to say,  the  antenna  never  merited  a mention. 

Sonya wasn’t naïve; she appreciated that  the  more  she  used  her

transmitter the more likely it was that she would be detected. It seemed,

therefore,  only  a  matter  of  time before British security arrived. As we

know, MI5 was indeed aware of her presence and should have been well

aware that an illegal transmitter was being operated in the Oxford area.

But they apparently never made the connection. This was made blindingly

clear when, in September 1947, she was interviewed at The Firs by two

MI5 investigators, one of whom was Jim Skardon, its famed (at least in his

eyes) interrogator. The two men used aliases, as was the way in this world

of  secrets,  and  despite  their  most determined  efforts  Sonya  outwitted

them  by  simply  refusing  to  answer questions.  Since  MI5  had  no

evidence  that  she  was  an  enemy agent,  Skardon’s  case  evaporated.

All  he  had  to  go  on  was  the confession made to MI6 in Berlin by

Alexander Foote when, just as month before,  he  had  defected  from  the

Soviets and presented himself at the legation in the British sector of Berlin.

There he told MI6 almost everything. He explained how Sonya had trained

him and Beurton as radio operators and went on to reveal, in great detail,

the activities of the Soviet-sponsored espionage  network  in  Switzerland.

But he insisted that Ursula Kuczynski was  no  longer  engaged  in  spying

Figure 2. This page (provided to the author by Antony Percy [7] &  wherever she happened to be. MI6 seemingly  swallowed  it  all  and

[10]) comes from the RSS file in the National Archives HW 34/23 and  relayed  their  findings  and shows a listing of daily RSS intercepts made between 16 March and  conclusions to their security service 16 April 1942. Though somewhat cryptic, it is clear that these are the  counterparts  in  England.  Sonya call signs of the stations transmitting and/or receiving. Note the  didn’t know this and naturally feared heading “RUSSIANS”so there’s no doubt RSS knew who they were  that MI5 and the police could arrive at

listening to – at both ends of those links. This is concrete evidence,  any minute. But they didn’t.

if ever any was needed, that RSS were aware of the transmitter  For Sonya, 1947 was consumed with “somewhere in Oxford”.  family tragedy. First her mother died

of the set-up.  At no time is there the merest mention of  and then, not long after so did her some form of DC to AC converter which may have allowed  beloved father. Sonya was now at her most vulnerable but Sonya to overcome this rather unfortunate shortcoming at  Britain’s  security  service  was  either  inept  or  simply  so The Firs. By that, admittedly rather cumbersome means,  hidebound in its procedures that the person best equipped she may have been able to use more batteries than the  to confront her, the highly astute Millicent Bagot, was side-

couple  –  “the  size  of  dictionaries”  –  that  she  had,  lined in favour of the much overrated Jim Skardon. And, apparently, to cart around from residence to residence.  as we have seen, Skardon failed spectacularly. 

Figure 3. A recent view of Great Rollright

August 2022

In August 1949, the Soviet Union exploded its first atom bomb, at least four years before the CIA believed they might achieve that exceptionally complicated scientific and technological feat. The reason they were able to surpass all Western expectations was because of Klaus Fuchs, the most dangerous spy in history [8]. And Sonya too.

The flight of Sonya and the fantasy of her radio activity

In February 1950, Klaus Fuchs was arrested and made a full confession that he had passed atomic secrets to the Soviet Union. The next day, the story was all over the newspapers which reported that he had transferred them to “a foreign woman with black hair in Banbury”. Sonya was  gripped  by  fear  but  nothing  happened.  She immediately planned her escape by booking three tickets on a flight to Berlin. She and her two younger children would go, Beurton, who was recovering from a broken leg following  a  motor-cycle  accident,  would  dispose  of  the contents of the house while her elder son would remain at university in Scotland. The final resting place of Sonya’s transmitter was, unsurprisingly a hole in the ground. No doubt,  though  she  never  mentioned  them,  the  other paraphernalia of her spying trade – the receiver and the power supply – also went to earth in an Oxfordshire field. On 28 February 1950, the aircraft carrying Sonya and her children  left  London’s  airport  for  Germany.  She  had escaped. The following day Klaus Fuchs was sentenced to fourteen years in prison.

MI5’s failure to make the connection between Fuchs and Sonya,  despite the  seemingly glaring  evidence against

her, remains one of the catastrophes of Britain’s Security Service history. However, this is not the place to delve into whether it was due simply to incompetence or to some deeper, darker machinations at the very highest levels. Others more competent than I have been there and their opinions are all in print. Remarkably the official history of MI5 ignores Sonya completely never even mentioning her name or, indeed, any of her names [9].

Of more immediate concern to us here is the mythology that  surrounds  Sonya’s  seeming  invincible  ability  to communicate, apparently at will, by radio, with the Centre in Moscow from any number of locations with far from sophisticated  equipment  and  even  in  the  absence  of electrical power. There is no need to go into great detail regarding the propagation of HF signals via the ionosphere but some aspects are so fundamental that they should be mentioned. A knowledge of the so-called maximum usable frequency  (MUF)  is  vital  to  those  planning  a communication  link  between  any  two  points  beyond ground wave range (Figure 4). The fact that the MUF is so variable between day and night, with the seasons and within the period of the sunspot cycle poses issues which have  to  be  addressed  by  those  planning  the  link.  In Sonya’s case, such details were not her responsibility but they were undoubtedly those of the Centre. Since she was alleged to have used her radio equipment from the mid- 1930s until at least the end of the war – a period spanning more  than  one  sunspot  cycle  –  there  will  have  been significant changes in the MUF over the various paths she said she worked. In fact, the sunspot number reached its minimum in February 1944, which means that the optimum communication  frequencies  will  have  been  decreasing

when  she  was  acting  as  Fuchs’s  wireless  link  with Moscow. In addition to the choice of operating frequency, this also has significant implications in terms of antenna length and also atmospheric noise. She will, therefore, have to had made changes to her operating frequencies to accommodate  these  natural  phenomena.  Her  account, and Macintyre’s parroted version, do not enlighten us as to  how  this  was  achieved.  Without  suitable  crystals, supplied to her by her masters in Moscow and not by the local hardware shop, Sonya’s communications activities will have been sorely compromised. And even had she had those crystals, the reliability of such low-power links will have  been  extremely  variable  as  every  QRP  operator knows.

During her long sojourn in East Germany, after fleeing from England so precipitately in 1950, Sonya changed her name to Ruth Werner and became a successful author of children’s  stories.  She  also  wrote  her  memoir,  as mentioned  previously.  The  version  in  English  has embellished  her  reputation  as  a  prodigiously  effective Soviet spy and wireless operator. It also served the cause of her communist masters, most particularly the Stasi, the East German secret police who, we can be sure, played a significant  part  in  carefully  scrutinising  every  word  of Sonya’s Report before it was released to the world.

I  end  with  one  final  reference  to  the  literature  on  this fascinating  woman  and  her  achievements,  but  more particularly  to  the  way  she  was  portrayed  in  Ben Macintyre’s recent best-seller. His book was reviewed in great depth and detail and the published review appeared, in 2021, in an international journal devoted to intelligence matters [10]. As book reviews go, this one is well-worth reading! 


  1. A Thomas.  A  tale  of  two  triodes.  Signal  2022,  62 (February), 46–51.
  2. I Underwood. Red Army GRU Colonel Ursula Maria Kuczynski. Signal 2022, 63 (May),14–16.
  3. O Matthews.  An  Impeccable  Spy-  Richard  Sorge Stalin’s  Master  Agent.  Bloomsbury  Publishing, London, 2019.
  4. B Macintyre. Agent Sonya – Lover, Mother, Soldier, Spy. Penguin Random House, London, 2020.
  5. B Austin.  HF  Propagation  and  Clandestine Communications  during  the  Second  World  War. Journal of The Royal Signals Institution 2009, 28 (1), 35–42.
  6. R Werner.  Sonya’s  Report.  Chatto  and  Windus, London, 1991.
  7. A Percy.  Misdefending  the  Realm  –  How  MI5’s Incompetence  enabled  Communist  Subversion  of British  Institutions  during  the  Nazi-Soviet  Pact. University of Buckingham Press, 2017.
  8. F Close. Trinity – The Treachery and Pursuit of the Most Dangerous Spy in History. Allen Lane, London, 2019.
  9. C Andrew. The Defence of the Realm – the Authorized History of MI5. Allen Lane, 2009.
  10. A Percy. Courier, Traitor, Bigamist, Fabulist: Behind the Mythology of a Superspy. Intelligence and National Security 2021, 36 (7), 1065–1075.


Figure 1. The author is grateful to …… for permission to use the featured photograph of Tensor Mk1. 



Figure 4. Graphs of the reliability of propagation over the 2560 km Oxford to Moscow path in     June 1942. They show the reliability for a given signal-to-noise ratio over a 24 hour period.      Marked on the graphs are the propagation      modes that would exist at various times for two frequencies of (a) 7 MHz and (b) 10 MHz. They also show the propagation modes of single and double ‘hops’ off the F1 and F2 layers, as 1F1, 2F2, etc. Clearly the 1F2 mode at 10 MHz yields

the highest reliability which peaks at just about

70% at 02:00 UT and falls rapidly after that. The lower frequency is always less reliable. Severe D-layer absorption is evident throughout the    daylight hours, being far worse, again, on the lower frequency. The complexity of the         propagation process should be obvious. In both cases the transmitter power was 20 W and the antenna was a dipole at a height of 6m

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1 Comment

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One Response to SIGNAL: Sonya’s Wireless

  1. I’m still in touch on facebook with Roy Vincent who must be one of the few people remember Sonya at Great Rollright. He writes this evening – “her son, Peter, told me ( we were both kids) mum
    Has a radio down there- meaning the cellar, which was normally kept locked. I see he is the only child alive now- have been seeking ways to contact him- he is well recognised for his own professional works”.

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