A History of French Transistors


Copyright Mark Burgess 2010

The first transistor to be produced in France was invented by Doctors Welker and Mataré of the Société des Freins et Signaux Westinghouse (F & S Westinghouse) in mid 1948 and announced to the World in May, 1949:

"This Wednesday, May 18, 1949, the Minister of PTT presided over the presentation of the transistron triode PTT 601 and some apparatus equipped with these devices at the laboratories of Service des Recherches et du Contrôle Techniques (SRCT) of PTT."

"Work on semiconductors conducted in France in recent years in collaboration between the Administration des PTT and the Société des Freins et Signaux Westinghouse has produced similar results to those of the Americans.

Building on previous work Doctors Welker and Mataré and a team of researchers prepared germanium of  high resistivity and started manufacturing high back voltage detectors, a prelude to the development of the of germanium triode or transistron triode. During the same year the first germanium transistrons manufactured in France, left the Laboratories. In French we could call this device "transistance" which is the literal translation of the American term "transistor." However transistance in French would be an electrical property like résistance. Thus we have the name "Transistron", from "Résistance de transfert," the suffix "tron" indicating active elements involving electrons or ions." [Sueur 1949 Courtesy P Zeissloff Le Forum de Radiofil]

In his publication René Sueur of the SRCT drew attention to parallels with the launch of the point-contact transistor by Bell Laboratories a year earlier: "A similar presentation was held in America at Bell Telephone Laboratories in 1948."  Both devices were point-contact types independently developed. Both organizations carefully orchestrated their publicity and secured newspaper and electronic press coverage.

Both exhibited applications for the new devices: in the case of SRCT an in-line telephone repeater, a three transistron AF amplifier, a four transistron telephone repeater, a 300m transmitter and a six transistron receiver that could drive a loud speaker (shown here). [Toute la Radio 1949 137]


The Transistron


The Westinghouse programme was led by Heinrich Welker and Herbert Mataré. Both men had been recruited from Germany after the war having played a key part in Germany’s war time radar programme. Mataré had previously worked in the Telefunken Microwave Receiver Laboratory and Welker on germanium point-contact detectors in association with Siemens. [Van Dormael 2009, Van Dormael 2010]

During the War Matare had worked on the duodiode for low noise radar mixer stages. His experimental duo-diodes had similar geometry to a point-contract transistor: two point contacts on a single germanium block positioned closely to one another.

In a brief retrospective responding to the celebrations of the 50th year or the transistor Mataré wrote to Physics Today reflecting on his wartime research saying “we sought ways to equalize the current voltage characteristics of crystal duodiodes for oscillator noise compensation. In fact, I made three-electrode crystals, trying to locate both top whiskers so that the current/voltage characteristics were identical. But the crystal material was so inhomogeneous that most tests failed to result in noise compensation.” [Mataré 1998]

In 1946 Westinghouse proposed to the Government that work begin on germanium and silicon crystal detectors covering raw materials, semiconductor production, purification, detector and their characteristics. A 6M Franc contract was awarded in December 1946 and funding began in March 1947. The contract was managed through the laboratories of Service des Recherches et du Contrôle Techniques (SRCT), controlled by the French Post and Telecommunications (Postes, Télécommunications et Télédiffusion or PTT).

At Westinghouse Welker and Mataré equipped a laboratory at Aulnay-sous-Bois. Their work focused on germanium detectors and by early 1948 had three prototype designs and a pilot production line that had a capacity for 3,000 detectors per month. In 1948 evaluation quantities of detectors were made and tested by the armed services resulting in design improvements. Westinghouse then set up a production line with a capacity of 10-20,000 germanium detectors per month. [Botelho 1994]

Mataré’s research also included work on a practical duo-diode. In 1947 this led to a design in which two composite semiconductive layers were formed in cavities of a single metal crystal holder which enabled the production of duo-diodes of closely matched performance. [Mataré 1947] 

Mataré recalls aspects of the research on diodes and how it led back to three electrode devices:

As Welker started the buildup of a Bridgman-type crystal furnace and produced pencil-like germanium rods that were cut for use in diodes, I installed the production line for making and testing the actual devices. In those tests, I renewed my work with two whiskers with the aim of exploring the barrier layer. I noticed that in some cases I got injection and amplification when the crystal had been cut from a larger ingot, and also when certain grain boundaries were present. So I asked Welker to increase the size of his graphite boats to grow larger ingots.”

“Finally, early in 1948, I was able to get amplification more regularly - that is, injection into a reverse-biased point contact. Our results were duly presented to the French government, published and patented.” [Mataré 1998] Picture of 1948 prototype Transistron courtesy Deutsches Museum Munich and BBC.

Botelho contradicts this suggesting that Westinghouse prototyped their crystal triode a little later in July 1948 citing a Westinghouse research report for the period July 1948-June 1949 entitled “Studies of Crystal Detectors” held at the Service Historique de l'Armée de l'Air (SHAA) archives.

The discovery was patented on August 13th 1948 and a handful made for further evaluation. In the first half of 1949 a 1000 triodes were made. In May 1949 Westinghouse received a further 7M Franc contract to continue its semiconductor research. [Botelho 1994]


Commercialisation of the Transistron


Little information about the transistors made subsequently is available. In 1952 a general purpose type, the Westcrel Type N, was presented at the Paris Salon National de la Pièce Détachée (the annual Paris components exposition) in a four transistor receiver featuring a regenerative detector and a three stage AF amplifier. The output stage produced 300mw with a 100v supply and was designed to power a speaker. The four stages were sufficient to pick up European stations on an internal antenna. [Toute la Radio 1952 165 courtesy Jean Claude Pigeon]

An example of a Westcrel H160 complete in its original box with its characteristics (but undated) is shown here courtesy of the Federation des Equips Bull. The two pictures are not to scale. [FEB 2008]

In a review of transistors available in France by Fred Klinger in February 1954 the Westcrel transistor type GAN 1 was given as the only example of a transistor available on the market and made in France. [Klinger 1954 courtesy of Jacky Parmentier] The remainder reviewed were made in USA. The GAN-1 was suitable for high frequency applications to 10 MHz with a power gain of 16dB and maximum collector voltage of 40V. 

[Picture courtesy Andrew Wylie shows an unknown Westcrel type. Externally this is identical to the FEB Transistron]

By 1955 junction types were arriving on the market from both French producers (CSF, Radiotechnique and LCT) and from the USA and the point contact types were soon redundant.

The principal semiconductors interest of the company remained point contact diodes: in 1955 it had a range of nine G5 series diodes for telecommunications and five G6 series for radio and television which it showed at the 1955 Paris components exposition. [TSF et TV 1955 318 courtesy Jacky Parmentier]


Centre National d’Etudes des Télécommunications (CNET)


CNET was established in 1944 in order to underpin the reform of the French telecommunications system with French technology. "CNET is entrusted with scientific research and general studies of national application in the domain of telecommunications." The intention was that CNET would integrate research being done by independent laboratories in France and coordinate the development of the industry. [Griset 2008] 

It took ten years to establish itself and overcome inter-ministerial conflict and, in 1946, the secession of its largest laboratory, SRCT, then directed by Pierre Marzin. In 1954 CNET’s governance was reformed under the PTT. At this time SRCT was reunited with CNET and Pierre Marzin became the director of CNET. [Mounier-Kuhn 1995] 


Demise of F & S Westinghouse and Technical Hegemony of SRCT


Marzin and Sueur did not intend allowing F & S Westinghouse to become the dominant party in the development of semiconductors.

They had already responded to the announcement in the United States almost 12 months earlier of the Bell Laboratories point-contact transistor. Their SRCT 1948 Annual Report included a remark on the prospects of semiconductor amplification noting "the future prospects to disrupt the entire vacuum tube technology." [Licoppe 1996]

"Marzin and Sueur have a new direction. The microwave detectors that F & S Westinghouse have had difficulty developing are certainly very useful for the future of microwave (and even more for military radars) but Bell Laboratories, for which Marzin and Sueur have profound admiration, announced in Physical Review in 1948, the invention on 23 December 1947, of a kind of solid state triode effect." [Bernard 2004]

In 1949 SRCT launched a semiconductor research programme and appointed Immanuel Franke to lead it. In this way they established an agenda to become the principal agency for semiconductors research in France in the 1950s. After SRCT was merged with CNET in 1954, this became the Département Physique, Chimie, & Métallurgie (PCM). [Licoppe 1996 Botelho 1994 Atten 1996]

Franke had been recruited from Germany to work on the hydrothermal synthesis of quartz, a war time strategic material. Initially his work was consolidated with Welker and Mataré at F & S Westinghouse, but in 1948, SRCT moved Dr Franke’s laboratory to the Réaumu buildings, rue Dussoubs, Paris. [Bernard 2004] Subsequently, semiconductor research was brought together in a new SRCT facility at lssy-les-Moulineaux.

At the same time they began to dismantle the research at F & S Westinghouse.

“M Pierre Marzin first asks that the contract with Westinghouse be restricted to pure contract research, probably to resist the temptation of the Company to exploit the contract to improve the development and commercialisation of its diodes.” [Licoppe 1996]

Complaints were voiced against the quality of F & S Westinghouse’s diode quality and its unwillingness or perhaps inability to invest in the necessary research infrastructure to take the work forward. "...more extensive investments are needed, such as manufacturing and purification of germanium and vacuum crucibles equipment that Westinghouse either does not want or cannot undertake.” [Licoppe 1996]

"The contract study appears to have been broken by mutual agreement during a stormy meeting probably held in the first half of 1951. Westinghouse would recognize its inability to continue baseline studies and prototyping of transistrons." [Licoppe 1996]

The company did continue to produce germanium diodes for a few years, with limited success. In 1953 a SOTELEC project team consider that that these diodes have "sufficient but not entirely satisfactory performance" [Licoppe 1996]

CNET laid claim to both applications research and basic research into semiconductor physics. "Sueur's strategy consists of identifying and highlighting to PTT transistron applications and to establish, thanks to a staged approach favoured by Marzin, research of a more basic character. This initial duality will deeply characterize and influence the early development of research on semiconductors at CNET." [Licoppe 1996]

The team Marzin and Sueur assembled included

Immanuel Franke crystallographer

Lantiéri to work on semiconductor properties

Georges Petit Le Du from F & S Westinghouse to work with Lantieri. 

Georges Petit Le Du for crystal growth

Marc Marais, chemist (purification germanium and its oxides)

The long term goal of this basic research on semiconductors at CNET is manufacturing grown junction transistrons, which they considered components of the future." [Licoppe 1996]

In 1951 they produced spectroscopically pure germanium oxide and used it to produce pure germanium. The following year they began making germanium single crystals by the Bridgeman and Kyripoulos methods and in mid 1953 successfully implemented Pfann’s zone purification method developed at Bell Laboratories. These developments enabled CNET to produce n-type germanium by doping molten germanium with antimony prior to pulling the crystal from the melt.

Maurice Bernard, who became Director of CNET, recalls the first steps CNET made towards a viable transistor:

"In October 1953 Dr Franke's group, where I was located, within the "celebrated" Département Transmissions du SRCT, made the first monocrystalline germanium.  We knew how to measure electrical resistance point to point, but needed to develop the measurement of minority carrier lifetime and the Hall effect etc. In particular we needed to learn how to make pn junctions and to manufacture and characterize some of the new junction transistors which had displaced the point-contact transistor.

Rene Sueur and  Emmanuel Franke encouraged the small team that I had formed. They shared our enthusiasm and gave us support. But what do we know about semiconductors? Nothing, we have everything to learn." [Bernard 2004]

1953 was a period of uncertainty on key technology options: the original point-contact transistor, the grown junction transistor or the alloy junction transistor? While CNET worked on the grown junction transistor Sueur proposed to CSF that they concentrate on the point-contact transistor in lieu of the alloy device CSF favoured. Fortunately for the future of CSF this advice was ignored. Andre Danzin who headed the RPC (Research Physico-Chemical) of the CSF politely resisted Sueur. [Licoppe 1996] By 1954 Sueur no longer defended the point-contact transistor but CNET continued to support grown junction research while sponsoring alloy junction research at CSF.

In 1954 crystal pulling methods were developed to enable the double doping method of producing grown junction transistors. These were inclined to have wide base regions but by 1955 CNET could produce grown junction transistors with reproducible base widths of 50 microns (2 mil). Finding the base in a grown junction transistor is difficult due to its narrow width and in 1955 a system is developed to enable this. [Photo Licoppe 1996  and insert showing the transistor mounted between the collector and emitter leads with the fine wire base connection]

In 1956 it had made grown junction transistors of modest RF performance (cut-off frequency of 2-4 MHz and with current gains of over 100).

Following the dual strategy set out by its Director fundamental research also progressed. For example, in 1955 Maurice Bernard published on research problems relating to the lifetime of minority carriers: an important determinant of current gain in transistors influenced by semiconductor quality. [Licoppe 1996]


The Tecnétron


The Tecnétron was invented by Stanislas Teszner in 1957 working at CNET. It was the first practical field effect transistor; a semiconductor amplifier that was first postulated by Lilienfeld in 1928 although never demonstrated.

The Tecnétron was made from an n-type germanium rod 2mm long and 0.5mm in diameter. Midway the rod was etched down to form a neck only 30 microns across and this area was coated with indium to make a barrier layer rectifying contact. Ohmic contacts were made to each end of the rod forming the anode and cathode of the device.

The field effect was exercised by a negative bias on the neck which was the control electrode. The negative bias repelled the electrons passing through the neck constricting them and creating an apparent increase in resistance between the anode and cathode. Unlike the original Lilienfeld  concept and modern planar devices Teszner obtained his effect in two dimensions giving a square law sensitivity.

The word Tecnétron is derived from the first two letters of the name of the creator (Teszner) followed by CNET and ending in the traditional suffix for an active device, “tron.”

At the time the high frequency performance of the device was remarkable: up to 500Mhz was possible. Toute la Radio suggested that the "tecnétron could provide an attractive solution to such problems of portable self-powered radio equipment, operating in VHF and even thereafter in UHF. Guided missiles and artificial satellites being two current examples." [Toute la Radio 1958]


Early French Producers


The key companies that produced transistors in the 1950s after F & S Westinghouse withdrew in the early 1950s were:

Compagnie Générale de télégraphie Sans Fil   (CSF), its associate company Société Française Radio Electrique (SFR) and manufacturing subsidiary Compagnie Générale de Semi-conducteurs (COSEM) ;

Laboratoire Central de Télécommunications (LCT) ;

La Radiotechnique ; and

Compagnie Française Thomson-Houston (CFTH).

This history emphasises the story of CSF because of its leadership position early on. It was at that time a wholly French company and, as a result, there is far more information about it in the public domain.

The other three companies all had international linkages: LCT was spun off as an International Telephone & Telegraph company, La Radiotechnique was owned by Philips and CFTH was an associate company of General Electric. 


Compagnie Générale de télégraphie Sans Fil   (CSF)


CSF was founded by Emile Girardeau after the First World War specialising in communications. From the beginning the company had a culture of investing in basic research and became one of the few industrial research laboratories in France. It hired Maurice Ponte, a graduate of the Ecole Normale Supérieure, to head the laboratory. In time Ponte became technical director, then CEO. By 1950 the company had 9,000 employees including around 750 in research. [Jacq 1997]

In 1952 Ponte decided to set up a semiconductors laboratory and looked for a suitable person to lead it. He settled on Claude Dugas who was at that time a postdoctoral fellow at Le Laboratoire de Physique at the Ecole Normale Supérieure. The laboratory had been founded in the late 1940s by Yves Rocard and Dugas. Pierre Aigrain was its most famous alumni. [Bernard  2004]

As a graduate, Dugas had studied in the USA at Carneigie Tech under Frederick Seitz where he began to build a network of contacts and collaborators including key people at Bell Laboratories. 

"I met Shockley, Experimenter Brattain and Bardeen. A few years later they had the Nobel Award for Physics and we met at l'Ecole Normale with Pierre [Aigraine] and they spent many important moments in our laboratory, the ideas of Pierre were influential and each year we had two or three people who came to see us."

Dugas goes on to describe how he was recruited by CSF to manage its Recherches Physico-chimiques laboratory (RPC) at Puteaux

"For some time M Ponte, a friend of Y Rocard of l'Ecole, wanted to build a semiconductor laboratory (diodes, transistors, and other planned developments). He asked M Rocard if he had a student that could take on the semiconductor laboratory....After a series of very serious discussions with M Ponte, I found myself Head of Department in June 1952, with a beautiful new office and sufficient means to order equipment, hire engineers internally and externally. In October, starting from nothing, I had some engineers, technicians picked from electron tubes and we are underway."  [Baruch 2002] 

In 1953 a pilot diode and germanium transistors line was installed.  [Daviet 2000]


External Influences


CSF did not seek a license from Bell Laboratories nor any arrangement with RCA unlike many of the early manufacturers (including European producers such as Philips, Siemens & Halske, Telefunken, BTH, PYE and GEC). [Lojek 2007] On a visit to CSF in October 1953, Edward Herold, who was responsible for RCA transistor research and development, met with Claude Dugas and Pierre Aigrain. He noted:

"It was emphasised that CSF has received no technical assistance of any kind in the transistor field, other than attendance at the RCA one day symposium a year ago (Dr Dugas). They have no Bell license, do not receive RCA Laboratory bulletins, and have no other company affiliations. They consider this a handicap since LCT has a Bell license and they believe that CFTH gets substantial help from the US General Electric Company." [Herold 1953]

The RCA Symposium on transistor production and applications held November 1952 was organised by Edward Herold. There Dugas saw 24 different transistor applications showcased by RCA (including an all transistor television set) and a small alloy junction production line. The line consisted of three operators. The first carried out acid etching of the wafers; the second applied the indium dots and loaded them into a furnace and the third attached the leads. [Herold 1983]

Dugas made at least annual visits to the USA as did Pierre Aigrain who acted as a consultant to CSF while working at l’Ecole. Discussing his USA network Dugas mentions MIT and Jacques Pankove who invented the RCA alloy junction transistor and who also visited Dugas at l’Ecole. [Baruch 2002 Pankove 1952] Pankove had been brought up in France leaving for the USA in 1942 when his family sought to escape Nazi persecution.

Some early publications might have looked useful but deliberately lacked any details. For example, RCA published a paper on its alloy junction transistor in 1952 giving only performance data for the prototypes prepared and a recital on the problems that might be encountered. The authors end a section on alloying unhelpfully noting:

"In general, excessive heating or too much indium causes the indium alloy to completely penetrate the germanium, thus causing an emitter to collector short circuit. Too little heating or too little indium results in widely spaced or inferior junctions and best transistor operation is not obtained. Between these extremes, excellent results are possible." [Law 1952]

Thus CSF relied on technology transfer from CNET, its relationship with the Ecole Normale Supérieure and informal relationships with US laboratories.


Germanium Transistor Research


The CSF had a transistor research contract from CNET from 1953 [Bernard 2004] and in return provided prototype transistors to SRCT for applications development.

But without a license and associated technology transfer package CSF had trouble developing the alloy junction transistor. In principal this was not difficult: simply alloy two tiny dots of indium on either side of a thin slice of n-type germanium!! But producing transistors of sufficiently consistent properties to support industrial mass production required mastery of subtle details across a wide range of materials technologies. For example, obtaining a consistent base width in a PNP transistor was determined by three key processes: preparation of the base slice from n-type germanium, fusing the collector indium dot then the emitter dot. 

CSF first made a base slice 3mm square and 0.3mm thick and then used chemical etching to reduce the thickness to 0.15-0.18mm. The collector and emitter were made in two passes through an alloying furnace at about 550oC. But variability in any of the stages led to uncontrolled base width of the transistor and lack of consistent transistor characteristics.

In 1954 CSF was still struggling with control issues. It found that its alloying furnace did not maintain consistent temperatures resulting in unacceptable variability even in a single batch of transistors.

These delays were unacceptable to CEO Maurice Ponte. In February 1955 he instructed the laboratory "to examine the progress of the germanium program. It is essential to review what has actually been achieved since the inception of the germanium laboratory compared to the expectations....draw conclusions about the program to define and follow" ending with an electrical insult suggesting the laboratory had “plenty of KVA but too few KW.” [Jacq 1997]


Development and Pilot Production at Puteaux


The laboratory had established a pilot production line with a capacity of 30,000 transistors by 1955. But production remained difficult: "It was very sensitive to any change in control of the germanium. The method was based on very strict feedback loops to adjust each parameter, for example, the temperature of ovens or the degree of doping on the slightest deviation in characteristics. Moreover, some aspects remain very mysterious. The engineers had found no clear explanation for a special liquid suggestively called "sauce magique" that improves the surface of germanium." [Jacq 1997].

The  first transistors produced at Puteaux were the TJN1 and TJN2.

As was commonly the case with most producers of this period, batches of these low powered AF transistors were sorted according to characteristics. Those with  a current gain of 40-60 where labeled TJN2 while those of lower gain, from 10-40, were labeled TJN1.

The TJN1 and TJN2 were painted white and carried the CSF logo. NPN junction transistors made at Puteau carried model numbers starting with TJP suggesting the initials represented “Transistor Jonction” N or P according to the polarity of the base pellet. [Photo of a CSF type C courtesy Christian Adam]


Laboratoire Central de Télécommunications (LCT)


The Laboratoire Central de Télécommunications (LCT) was founded in 1927. It was a condition of an agreement by ITT with the French Government when International Telephone & Telegraph (ITT) won a tender to supply an automatic telephone network for Paris and agreed to establish a research laboratory as part of the deal. The laboratory was quickly established with a staff of several hundred researchers by recruiting them from ITT’s international associates such as Bell Telephone in Antwerp and STC in Britain.

LCT was responsible for many break-throughs in radar and telecommunications under its Director, Maurice Deloraine. LCT researched electronic switching from 1945 and built its first automatic exchange in 1956. In 1970 LCT installed its first digital exchange at Roissy. [Chapuis 2003, Cultures France]

After his return from the USA, Pierre Aigrain worked for two years from 1948 at LCT while at the same time having an appointment at the Y Roccard’s laboratory at l’Ecole. At LCT Aigrain worked on electronic switching although the lack of adequate semiconductors prevented progress. [Dupuis 2007]

The bulk of the work of the laboratory was done under contract to the French Government. In 1953 they had a Bell transistor license and while they had a germanium point-contact diode fully developed had not made any progress with transistors. [Herold 1953]

LCT produced two point-contact transistors:

3698 (switching)

3768 (general use)

They were produced in outlines very similar to that of Western Electric (but not identical) with similar type numbers (ie 1698 and 1768).


La Radiotechnique


La Radiotechnique was formed in the wake of World War I in 1919 to produce vacuum tubes: one of four companies making these in France. They were bought out by Philips in 1931 in order for  Philips to avoid paying damages to La Radiotechnique when Philips lost a court battle over patent infringements. [Tyne 1977] The other key subsidiary companies relevant to the story of semiconductors were Valvo Germany, Mullard Great Britain and Amperex in the USA. The Philips group worked as a loose alliance in which research and development was not strongly coordinated from Eindhoven. Semiconductors were produced at all the above sites under a common numbering system but there are many examples of transistors being produced in Holland, for example, and re-branded.

Compagnie Française Thomson-Houston (CFTH)


The Thomson-Houston Electric Company was formed in 1883 in the USA to buy out Houston's American Electric Company. In 1892 the company merged with Edison to form the General Electric Company (GEC). One year later the Compagnie Française Thomson-Houston (CFTH) was set up as part of GEC’s international strategies.

Prior to the transistor era, CFTH had a contract from Air Force to develop and make silicon radar detectors which it did according to “English” designs. [Botelho 1994] Its associate company, British Thomson Houston (BTH), had developed and manufactured silicon radar detectors during WWII [Seitz 1996] and who provided technology assistance. [Herold 1953]

The CFTH, France's second largest electronics firm, faced internal resistance from its tube people, and initially did little semiconductor research. A serious effort did not start until 1956 with the help of General Electric Co (USA which would lead to a semiconductor joint venture in 1961, SESCO.” [Bauer 1997]

The slow start of CFTH on semiconductors is confirmed by Addison Sheckler who began at General Electric at Syracuse NY in 1948. He was assigned to the GE semiconductor programme late 1948 production in order to work up germanium purification and continued for 14 years through the silicon era and onto the first LEDs. He recalls: 

"In 1951 and '52 we were told to teach some other companies our technology. The first of these was an affiliate BTH (British Thompson Houston). This went very well and the association lasted for several years. We were also told to teach CFTH (Compagnie Française Thomson-Houston) another affiliate. We did so and they were in business but our association with them was short lived." [Sheckler 2004]

In October 1953 during Edward Herold’s visit to France he met with M Mercier who was responsible for work on germanium in the radar section of CFTH. At the time CFTH were making four silicon crystal point-contact diodes (their types 8023B and 8021B roughly corresponding to US mixer types 1N23B and 1N21B and video detectors corresponding to 1N31 and 1N32 types).

Mercier was working on germanium purification using the Czochralski method of drawing a single crystal from molten germanium. Herold noted: 

"There is rather little at CFTH in the way of completed devices. They work on point-contact transistors, power junction rectifiers and junction transistors but have not gone far on any one. They plan, however, to make a 6 volt 10 ampere and a 50 volt, 50 ampere junction rectifier." 

In addition they were working on a point-contact germanium high back-voltage diode. "The chief object is low cost and Philips is the main competitor." [Herold 1953]

By 1955 nothing had changed. Toute la Radio’s Guide des Transistors listing all transistors available in France noted that La Radiotechnique, CSF and LCT were producing transistors and that importers were selling Raytheon, Siemens, Radio Receptor, Sylvania, RCA and Philco transistors. General Electric transistors were not available and there were no entrants from CFTH. [Toute la Radio 1955 198]



The General Electric heritage is clear from this picture on the right of a CFTH transistor [Toute la Radio 1958 230] and a schematic drawing of a General Electric type [GE Transistor Manual]


The First Junction Transistors 1955


1955 was the year of the junction transistor for three French companies: CSF, LCT and Radiotechnique. For the first time junction transistors made in France were available.

The 1955 Paris Salon National de la Pièce Détachée was an important focus for French component manufacturers. In 1955 it was held from 11th -15th  March and was open to the Trade only. [Scan Toute la Radio 1955 194]

Five companies featured semiconductors at the Salon:

CSF and  SFR




After nearly three year’s of development effort, CSF wanted to publicise its progress. In the March 1955 Toute la Radio CSF invited guests to its stand at the Salon advising that "Through its work on semiconductors the Département de Recherches Physico Chimiques presents the germanium PNP junction triode types TJN1, TJN1B, TJN2 & TJN2B  intended for use in amplifiers or oscillators operating at frequencies up to a few hundred kilocycles."

This series is considered by the fraternity of French collectors to be the first commercial junction transistors to be manufactured in France. [Adam 2009] In addition CSF showed a prototype power transistor (TJN100). SFR had a junction rectifier rated for 400V and 300ma.

Radiotechnique showed its low powered AF transistors, the OC70 and OC71 that were available and the medium power OC72 and higher power OC15 that were exhibited but as prototypes.

CFTH had little on offer, the review of the Salon in Toute la Radio noting that they were still working on point-contact types.

LCT while acknowledged, received no report.

In the view of the authors of the report, however, “the highlight of the Exhibition was in an application other than germanium transistors: the photodiode junction (developed in France) presented by the Radiotechnique.” [Toute la Radio 1955 195] This is an odd conclusion given the importance of the new transistors in their historical context. The TJN series did not survive (being replaced by the SFT series) but the OC71 was still in production in the 1960s.


State of the Art 1955


In September 1955 Toute la Radio published its first Guide des Transistors which listed all transistors produced in France at that time (and some USA types and their French importers).

This covered only junction transistors including the TJN1 and TJN2 and OC70 and OC71 already featured at the Salon and, additionally, the LCT 3604, a NPN low power AF type and the Radiotechnique medium power output transistor, the OC72. [Toute la Radio 1955 198]




Pc Max


















PNP AF Preamplifier















PNP AF Power


2 watt







* Low  noise versions of these denoted TJN1B and TJN2B were also produced



[CSF advertisment from  the March Toute la Radio 1955 194

Radiotechnique advertisement (September 1955) states: "In the field of semiconductors La Radiotechnique has already moved some technologies from its research laboratories and begun mass production" illustrating the same transistors covered in Guide des Transistors. These were:

OC15 power transistor (described as a prototype)

OC70 first stage amplifier

OC71 audio amplifier

OC72 output transistor [Toute la Radio 1955 198]


Radio Frequency Transistors and the First Transistor Radios


An obvious application for transistors was in portable radios where the low power consumption would give vastly improved battery life. The first transistors were only suitable for the audio stages (AF) and some hybrid sets were made using tubes in the radio frequency (RF) stages and transistors for the output stages.

Thus an early goal by all transistor companies was to produce RF transistors that would permit an all transistor radio.

Salon de la Pièce Détachée 1956 : New IF Transistors


At the 1956 Salon over the 2nd to the 6th  March only two RF types were announced by French manufacturers :

Radiotechnique         OC45 Germanium PNP

LCT                        3609 Germanium NPN

[Toute la Radio 1956 205]

Radiotechnique were anticipating the OC45. In the same month it stated "a OC45 HF junctions triode for which samples will be available in the near future." [Toute la Radio 1956 204] Philips released the OC45 at the Amsterdam Firato 8-15th October and Valvo in the fall of 1956. A further indication of a premature announcement is that at the Salon a cut-off frequency claimed was 5Mhz whereas it was subsequently put at 3 Mhz.

LCT continued its tradition of making NPN transistors. Its 3609 had an alpha cut-off of 1.8Mhz.

Both the OC45 and 3609 were suited for IF frequency amplification and the OC45 was used for many years in this application.

CSF Developments


During 1956 CSF had an active programme to develop an RF transistor with a view to producing a quality dual band receiver.

Jean-Piere Vasseur was a senior applications engineer at CSF who had a leading role in the transistorisation of French communications equipment. [Bernard 1996] In April of 1955 he wrote and article for TSF & TV magazine summarising progress made with new transistors and featuring a complete prototype receiver using experimental transistors. 

The future was rosy and he noted "Experimental power transistors are capable of delivering several watts at audio frequency, other experimental transistors can attain frequencies of up to 100 Mhz. The applications of these transistors are the same as tubes in the domain of power and moderate frequency. This domain will cover more and more as development progresses."  [Vasseur 1955 courtesy Jacky Parmentier. Scan and insert courtesy Jean Claude Pigeon]


1956 Foire de Paris


The 1956 Foire de Paris for radio, television and hi-fi occupied 10,000 m2 and 13,000 exhibitors from France and 26 other countries showcasing their latest developments. Journalists from Haut Parleur were there to discover what was new and in regard to transistor portables found that: "The Foire de Paris in 1956 showed us first ultra-portable transistor Radios, particularly foreign imports. Availability is still limited and their prices very high, but these are the promise of the future. Similarly, perhaps, as regards the use of printed circuit assemblies to reduce size, weight, reduce cost price and ease assembly."  The only transistor set mentioned was the Fanfare Transivox. [Le Haut Parleur 1956 980]

Fanfare Transivox


The Transivox was described by Haut Parleur as "the first French receiver equipped entirely with transistors." In its special edition of October 1956 more details were given: It was an 8 transistor set with four RF “special” transistors and an audio amplifier line up of two OC71 and two class B OC72. [Le Haut Parleur 1956 Numéro Spécial] It featured long and medium wave bands and was powered by four torch batteries.

No details were given as the identity of the RF transistors. The inference in the term “special” is that they were handpicked from production but there are no hints as to the manufacturer. [Picture Le Haut Parleur 1956 980]


Solistor Transistor 8


The Solistor Transistor 8 was launched in August 1956 featuring on the front covers of Toute la Radio and Haut Parleur in December of that year. It was designed and manufactured by Radio-France, a subsidiary of CSF using CSF development transistors. The set was initially marketed by AREL but subsequently by Clarville as a result of the merger of their interests. This was a two band set:

Long Wave              150-360 Khz.

Medium Wave          525-1600 Khz.

Early on there were considerable production difficulties. The release was planned for June but the first shipments were not made until August. Of 820 sets shipped, 160 were returned as defective. [Jacq 1994 Cited by Fesneau Picture from Toute la Radio 1956 211]

It is generally considered the first “all French” transistor receiver. The CSF transistors were simply labeled with letters A-G according to their function. This suggests that they were selected from production, a practice common to other manufacturers prior to obtaining rigorous quality control.


Schematic Ref

CSF Transistor










First IF



Second IF



Detector/1ST AF



AF Driver



Class B Output

Q7 and Q8



The design of the set deliberately minimized RF transistors using only two for the oscillator and mixer. The IF frequency selected was exceptionally low at 130 KHz in order for the IF transistor specification to be less demanding. (Standard was 455 KHz. Other early sets such as the Texas Instruments Regency TR-1 used an IF Frequency of 262 Khz for similar reasons.)

The set is also known as the Solistor model 57 PP 416.


1956 Guide des Transistors


The 1956 Guide by Toute la Radio reported nothing new from Radiotechnique or LCT (but the OC45 was now rated at 3Mhz). Despite the use of its transistors in the Solistor 8 CSF had yet to announce any RF types.

CFTH listed standard General Electric types: 2N135, 2N136 and 2N137. They were all germanium PNP transistors with typical performance of 4.5, 6.0 and 10.0 Mhz respectively. There is no confirmation on whether these transistors were produced by CFTH or imported. [Toute la Radio 1956 209]


Salon de la Pièce Détachée 1957 : New RF Transistors


At the 1957 salon (from 29th March 1957) CSF announced RF transistors with type numbers for the first time, although they had been supplying these for radio production since late 1956.

CSF                        TJN7 Germanium PNP

Radiotechnique         OC44 Germanium PNP

In addition CSF introduced its first IF transistor as a companion to the TJN7:

CSF                        TJN6 Germanium PNP

These developments represent the end of the line for alloy junction technology. New technology would take over such as the drift transistors/POB transistors from Philips and RCA and then silicon diffusion.


The Improved Solistor


By 1959 there were many transistor receivers on the market. But the new Clarville PP429  is of special interest as it was released in a very similar cabinet design as the original Solistor 8 but with six transistors and two diodes:



CSF Transistor





First IF


Second IF






AF Driver


Class B Output


Clarville 1959


This was a conventional transistor receiver of its day: now with a IF frequency of 480 Khz and representing the extent of development of the alloy junction transistor for long and medium wave bands. Good short wave performance required RF transistors with new technology.


Power Transistors


Power transistors were needed for audio amplifiers (but typically not in portable sets), invertors and servo- drivers. In order of their development the first power transistors from the major French manufacturers were:

Radiotechnique         OC15

CSF                        TJN100

CFTH                      TH8501

Radiotechnique OC15 Power Transistor


The OC15 was designed by Valvo and released in Germany in October 1954 [Herzog 2001] Early versions were known as the 100 O.C. Both versions are shown here. [Photo courtesy Arnaud Cramwinckel] It was rated at 3 watts dissipation in class A and at 5 watts class B output. [Knight 2007]

Despite the apparent fragility of small signal devices, power transistors of respectable dissipation were made by several manufacturers relatively early. Key features in the approach to these were to have “large area” junctions and good heat transfer to the case which were designed to fit to heat sinks. The penalty for large junction areas was control of the base width and consequently consistency and high frequency performance.

The OC15 had an elaborate stud mounting design: “three layers of steel housing, three glass relief insulators, a large insulated bottom layer, and the top-hat heat sink, which is made with resin inside with a copper heat tab.”  [Knight 2007] Part of the complexity was due to the electrical isolation of the transistor from the case; a practice not followed in subsequent designs such as the OC16 where the collector is connected via the case with consequent improvement in heat transfer.

Radiotechnique advertised the OC15 as a prototype n September 1955 and it was the only power transistor included in the Guide des Transistors for that year. [Toute la Radio 1955 198]. It took, however until mid 1956 to be available, the March edition of Toutle la Radio promising that it would "emerge in May.” [Toute la Radio 1956 204]


CSF TJN100 Power Transistor

CSF began work at least as early as 1955 (and probably much earlier) as noted by its applications engineer Jean-Pierre Vasseur in an article for TSF & TV in April 1955 [Vasseur 1955]

CSF first advertised its new TJN100 power transistor in March 1956 to publicise its stand at the 1956 Salon de la Pièce Détachée. It had used a similar strategy a year earlier when it introduced the TJN1 and TJN2 just prior to the 1955 Salon. It was advertised for applications in PA systems, remote control and inverters.


The new transistor was rated for 2 watts maximum collector dissipation and an output of 0.75 watts in Class A and 3 watts in Class B. [Picture from CSF advertising]

Higher powered transistors were in the pipeline: A report from the 1956 Salon advised “CSF have new TJN: we saw a model with collector dissipation up to 10 W, especially designed for servomechanisms. Hopefully it may soon be commercially available.” [Toute la Radio 1956 205]


CFTH TH8501 Power Transistor


In a similar manner CFTH used the 1956 Salon to foreshadow new transistors: “Transistors also appear from Compagnie des Lampes and CFTH where an AF model is available in April (power model for evaluation).” [ Toute la Radio 1956 205]

In October the TH8501 was advertised in Toute la Radio. It had maximum collector dissipation of 3 watts. Picture from CFTH advertising 


Developments in 1957


By the time of the 1957 Paris Salon new models were being announced. CSF had its TJN30 and TJN300 on show. Both would be redundant within a year being replaced by the new SFT types (SFT113 and SFT114).

The OC15 which was complex to produce and by now an obsolete design due to the manner in which the collector was electrically and thermally isolated from the case was to be replaced by the new OC16 in June of 1957. The OC16 followed what was now industry practice by connecting the collector via the case. [Toute la Radio 214 1957]

CFTH reportedly had mystery "types 11-16 T1, dissipating up to 2.5W on their collector for AF power amplification."  [Toute la Radio 215 1957] These transistors were not part of the CFTH power range in 1958.

[Left TJN300 and TJN30 types and right the new OC16 and in background medium power OC72 metal encapsulated types with fins to improve heat transfer. Pictures Toute la Radio 1957 214 & 215]

Company Developments 1957-1958


In the period 1957-58 Junction transistor technology matured and improved models were released by all manufacturers.

Research was invested in silicon, particularly by CFTH, early on.

CSF built and opened its new semiconductor facility at Saint- Egrève near Grenoble.




CFTH had a leadership position on silicon having been engaged on silicon radar detectors prior to the transistor era.

In 1955 CNET gave CFTH a contract to develop methods for growing silicon crystals and the development of crystal growing apparatus. [Licoppe 1996] 

By 1956 its progress was becoming apparent as reported from the 1956 Salon:

"To report a new phenomenon: germanium is living dangerously with silicon. It has to date been very difficult to produce monocrystalline silicon, because of its high melting point (1500 oC), exceptional activity and reactivity with everything. But it seems that these difficulties are being resolved as we have seen a CFTH single silicon crystal about 10 cm long: world record, it seems.

The silicon threat is seen almost everywhere, because it is much less sensitive to heat, it is much more naturally available than germanium, and allows very interesting applications. Note however that it still costs far more than germanium." [Toute la Radio 205 Mai 1956]

An example was provided from a new silicon junction diode: 

"The silicon junction diode from C.F.T.H. has the following properties: maximum reverse voltage of 600 V; rectified current: 500 mA forward voltage drop at 500 mA: 1 V... We have seen a sample of this diode operate in a vessel full of boiling water with uncompromised performance." [Toute la Radio 205 1956]

The STTA (Service technique des télécommunications de l’Air) also sponsored the development of silicon alloy junction technology. In 1957, the STTA awarded two research contracts for silicon transistors and silicon rectifiers of small, medium and "large" rating. The contracts were awarded to CSF (PRC) and CFTH. On Easter Friday the first five silicon French transistors were delivered to STTA by CFTH. These transistors, as well as the rectifiers used alloy junction technology with inferior performance.  [Bergounioux 2003]

Thus in common with other manufacturers such as RCA and Raytheon that experimented with alloy diffused silicon transistors CFTH came to the conclusion that alloy silicon transistors were impractical. Diffusion became the accepted technology for silicon.

By 1958 CFTH had two silicon transistors as part of its commercial range:




PC max


Alpha Cut-off




50 mw

30 V

3 MHz



50 mw

30 V

5 MHz






[Source Toute la Radio 1958]



Production of CSF Transistors by COSEM at Saint-Egrève, Grenoble


Ponte committed CSF to move forward despite the lack of consistent process at Puteaux. The first commercial target was a range of transistors for portable radios. It created COSEM, Compagnie Générale de Semi-conducteurs, its semiconductor manufacturing wing in the mid 1950s based at Saint-Egrève. This site was chosen for its proximity to the University at Grenoble with its specialization in advanced technologies including nuclear technologies and a dexterous female workforce redundant from the decline of the hand-made gloves industry. [Toute la Radio 228 1958 Picture of the COSEM factory from Le Haut Parleur 1958] 

But while the laboratory at Puteux could produce transistors, COSEM found them ill-suited for mass production. There was a cultural gap between research and production: 

"The gap between the basic research orientation of the RPC laboratory scientists and the production process orientation of the COSEM engineers was a constant source of friction that affected the firm's capabilities in semiconductor production." [Botelho 1994]

[Picture: Mass production at Grenoble featured large number of female workers each undertaking a stage in the production. Credit René Bouilot and Georges Bru from Gillet 1964]

Transistor production at Saint Egrève followed industry standard methods by assembling the germanium pellet, indium dots for the emitter and collector and the base tab in a jig to hold their alignment during firing. The use of large numbers of female workers using microscopes to carry out delicate operations also followed normal industry practice. [Le Haut Parleur 1006 1958 courtesy Christian Adam]

Picture: Exploded view of a transistor. Picture credit René Bouilot and Georges Bru from Gillet 1964]

By 1958 most production of commercial types was centred at Saint Egrève. Two  power types, SFT113 and SFT114 were still being produced at Puteaux and possibly other low volume transistors.

The November 1958 edition of Toute la Radio published a comprehensive article on all transistors then being made in France. This included the following range of transistors for CSF:


RF PNP Types produced at St Egrève



Alpha Cut-off

Current Gain











 3 Mhz


-6 v

1 ma



 6 Mhz


-6 v

1 ma


RF Mixer

 10 Mhz


-6 v

1 ma







RF NPN Types









Alpha Cut-off

Current Gain

PC max

VCB  max



 2 Mhz


120 mw

30 v



 2 Mhz


120 mw

30 v



 4 Mhz


120 mw

30 v



 4 Mhz


120 mw

30 v


RF Mixer

>4 Mhz


120 mw

30 v


RF Mixer

>5 Mhz


120 mw

30 v



Low Power AF PNP Types




PC max

VCB max

VEB max

IC max



Small Signal

100 mw



10 ma



Small Signal

100 mw



10 ma



Small Signal

100 mw



10 ma



Class B

100 mw



100 ma








*VC  @ 6 V

*Replacing Puteaux TJN series produced at St Egrève



Power AF PNP Types produced at Puteaux


PC max

VCE max

IC peak



4 W

30 V

5 A



4 W

30 V

5 A*


*Max inverse current less than for SFT113. Both available with VCE max of 60 V



Family of CSF case styles in the period 1955-60 indicating the transition from the left, early production from Puteaux (CSF Type C) to the flange style in black paint which became the standard outline for low power junction transistors made at Saint Egrève (SFT121). The blue-green outline was typical of transistors made at Puteaux around 1956 as seen in examples of the Solistor Transistor 8. [Picture courtesy of Christian Adam]



By 1958 the list of CFTH transistors published by Toute la Radio included a large number of standard GEC types in addition to two silicon RF transistors unique to CFTH:


CFTH Power Transistors 1958



PC max

VC max

IC peak

Current Gain



5 W


2.5 amp



5 W


2.5 amp



5 W


2.5 amp



12 W





12 W





12 W




[Source Toute la Radio 1958]



CFTH General Electric Types in 1958



PNP RF Mixer



2N135 2N136


2N186 2N187 2N188 2N189 2N190 2N191 2N192

PNP AF Class B

2N186A 2N187A 2N188A




[Source Toute la Radio 1958]





By 1958 the commercially available range of transistors had not progressed much since 1957 with the new entrants being the OC139-141 series. These were alloy junction NPN germanium types generally described for “high speed” switching applications although other uses  were promoted: for example the OC140 in a complementary symmetry AF output that was used in a small number of transistor receivers. [Toute la Radio 1958 230]

By 1958 the development opportunities in germanium were virtually exhausted although many of the familiar germanium transistors such as the OC71, OC72 OC44 and OC45 and many others were produced well into the 1960s.

The next wave of innovation took place in the USA with the development of diffused silicon, mesa and planar technologies and ultimately integrated circuits.



What became of the early energy and inspiration in the recruitment of new scientists and the re-invention of the transistor? Why did the leadership shown early on not lead to a vibrant French semiconductor industry and why was the door left open to its colonisation by US competitors?

France had focussed too long on germanium. CNET did not support the development of silicon early enough believing that germanium was sufficient for the near future. Even in its most advanced applications such as the RCA drift transistor and the Philips’ pushed-out-base adaptation, germanium was a developmental dead-end. What mattered was silicon, initially in discrete components and then integrated circuits. Successful semiconductor survivors mastered silicon early and adapted it to new diffusion technologies and used these in integrated circuits. Most commonly, start-ups began with silicon and succeeded through an immediate innovation taken rapidly to market.

In  France, research on integrated semiconductors began in 1960. General Electic and CFTH formed the Société Européenne des Semi-Conducteurs (SESCO) in the 1950s. SESCO started producing integrated circuits by assembling discrete silicon components in TO5 packages commercialising these by 1964.

Work on conventional integrated circuits (single chip) began at CSF with assistance from the French government in 1961. CSF also collaborated with CNET in the development of FET devices.

Radiotechnique obtained a government contract to develop linear circuits and invested in its own digital technology. It was probably inhibited by indecisive strategies of its parent, Philips.

In addition these companies and others such as Compagnie des Produits Elémentaires pour Industries Modernes (COPRIM) developed and produced thin-film circuits. [Dummer 1964]

The first mass production of integrated circuits in France was by Sovcor in 1967 and by this time five US companies were established in France: Texas Instruments, Fairchild, ITT, Mororola and Transitron. In the face of this competition, Thomson merged with CSF, and their semiconductor interests (SESCO and COSEM) were merged to form SESCOSEM. This company was supported with large government contracts to the extent of 20 MF between 1969 and 1973 [Mounier-Kuhn 1994] and foreign assistance through licensing arrangements from US companies General Instrument, National Semicon and Motorola. [Morris 1990] By 1972 SESCOSEM was the only French semiconductor company in the top twenty global companies. The future was not promising: Botelho suggests “France's innovation record during the following decades was negligible.” [Botelho 1994]

Botelho advances cultural reasons for the lack of a global semiconductors industry in France: “The French rationalist scientific world-view and mathematical mindset of its elite engineers had trouble dealing with the interdisciplinary, messy and unpredictable semiconductor technology. Predictably, the response was to pursue more abstract and theoretical research. The systematic and scientific were privileged over the experimental and technological.” [Botelho 1994]

But this does not explain why mainstream advanced electronics companies with a long history such as General Electric, RCA and Philips were equally unsuccessful long term in the fast moving field of semiconductors innovation notwithstanding their early leadership. Within the major cycles of innovation such as the transition from discrete transistors to ICs, technology chaos reigned as companies leapfrogged one another with new developments resulting in dead-ends for some and spectacular kudos for others. The early development of germanium generally seems to have disadvantaged the early adopters. Long term success went to those that as start-ups mastered the materials technologies needed for silicon.

The only company with the capacity to create an exclusively French presence in global markets was CSF. Mounier-Kuhn analyses its failure to do so:

The short term view taken earlier by its management in favour of germanium saddled the company with a certain amount of technical backwardness. According to the then head of the CSF St Egrève laboratory, the most difficult technological revolution the component manufacturers had to contend with was not the germanium transistor, which did not require a production organisation essentially different from the vacuum tubes’, but silicon, an especially difficult material to handle. In addition, St Egrève, in the Alps, was 600 km from the Paris CSF laboratories and communication between the two was slow and arduous; whilst the key to success in micro-electronics lies in improving the fabrication processes, and this requires close collaboration between research and production. Further, CSF was not accustomed to mass production. Its priorities were for custom products made in small numbers for the Army and for nuclear research, which offered few possibilities of economy of scale — a tentative diversification into radio and TV for the mass market failed; as for discrete components, its publicity boasted "Cosem, the main European producer of diodes". It left the gate open for silicon components, through which the new American companies poured — Texas Instruments, Fairchild and Motorola: France was Motorola's main customer in Europe in 1966, with a turnover of $ 2 M.” [Mounier-Kuhn 1998]

Reviewing the role of CNET and commenting on the grown junction transistor strategy Bernard observes:

The history of the early development of the semiconductors industry in the world is well known and one is struck by the innumerable industrial failures lining the road. In the late '50s, one of the developments carried out at CNET is the npn transistor, made by drawing it from a bath of liquid germanium [Grown Junction Transistor]. It was questionable. The technique, initiated by Bell Labs, reproduced successfully at Issy-les-Moulineaux in the laboratory of Petit Le Du, gave rise to a contract research study among French manufacturers, including French company Thomson Houston. This method was intended as an alternative to the germanium indium alloy transistor developed by Philco, RCA and CSF. In fact neither of these two techniques survived in industry. Silicon diffusion inexorably prevailed.” [Bernard 2004]

Lynn points out that while the transistor was invented in the United States, by 1960 Japan was producing more transistors than the United States. But the United States surged ahead as silicon replaced germanium in discrete devices and integrated circuits (IC) became important. The first IC calculator was developed in the United States but within a few years Japan controlled markets for this and many other solid state consumer products. By the mid 1980s Japan was again ahead on semiconductor production but in the 1990s it lost ground to Taiwan and Korea for commodity semiconductors and the United States for sophisticated new products. [Lynn 2000]

Retrospectively Bertrand took a charitable but restrained view of the Tecnétron, a good example of a technology leading in a strategic vacuum:

The commercial developments of the "Technétron" and the "Gridistor" which followed it, were not the way ahead. The rocky fields of the technology battle are inevitably littered with corpses. Some [Botelho 1994], have questioned French industrial failures. We may not unreasonably highlight the lack of consistency between policy and the legions at CNET and uncertainty in the same French telecommunications strategy. But simplifying this case is to refrain from understand the deeper causes of a situation that is found in all countries comparable to France. In the industrial field failures were numerous in all countries, US included. These failures, like those in the field of computers which were also numerous, have multiple and complex causes.” [Bertrand 2004] 



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Further Articles on the Transistron

A page dedicated to the Transistron, the first French transistor, has been established here on this site. Readers should also follow the Radio Museum thread dedicated to this subject.



The author acknowledges the extensive research of company and institutional archival material by academic writers Michael Atten, Antonio Botelho, Sylvie Daviet, François Jacq, Pierre Eric Mounier Kuhn and Christian Licoppe and the important personal histories Pierre Aigrain, Claude Dugas and Maurice Bernard that have provided the foundation for this article.

The forum moderated and encouraged by Christian Adam on Radiomuseum.org, its members and leading contributors Jacky Parmentier and Jean Claude Pigeon  have provided significant additional material from the French technical literature. Jean-Marie Birsinger has provided the author innumerable relevant copies of the popular electronics journal of the day, Toute la Radio and other similar publications.

Since beginning this article I found that Christian Adam was writing several articles on the history of French transistors and we agreed to collaborate by pooling information. Collaboration has enriched both endeavours. I am indebted to him for providing additional references and information. His article, Histoire du transistor à pointes en France has been published at Radio Museum and is an excellent and well illustrated account of the development of the Transistron, the first French transistor, in the context of developments in the USA and Germany


Key Links


The purpose of this history is to provide new information for English readers regarding the development of transistors in France. The story of the first French transistor, the Transistron is well told in English. See, for example, Michael Riordan’s account How Europe Missed the Transistor and Armand Van Dormael’s The French Transistor   For this reason the account of this important development is relatively cursory in this article, although with the inclusion of new material.

The Radio Museum   provides comprehensive information on tubes, transistors and receivers and is worth joining to obtain maximum benefits from its database.

The site “Pocket-Transistor” is a superb resource for information about transistor receivers including the Solistor 8 mentioned in this text   as is a site by a well known French collector Jean-Claude Pigeon and Jean Luc Fournier on the early French transistor receivers.


Additional Resources


Useful additional resources have been posted on this site to supplement those available at Radiomuseum.org and many other internet sites.

Subpages (1): The Transistron