The long-established Hungarian electrical manufacturer Tungsram famous for the production of electric lighting, produced germanium diodes and transistors. They seem to have started by copying some USSR types, moved on to the Mullard/Philips OC series, and then the standard pro Electron series AC, AD, AF and possibly others. They also produced devices in some Eastern European series, and diodes in the OA and AA series. The history of Tungsram is documented in two books (in Hungarian): 'A Tungsram Rt. története, 1896-1996' and 'A TUNGSRAM márka története'. Tungsram is a Hungarian brand, and not a single factory. The main factory was Egyesült Izzólámpa és Villamossági Rt..
A confusion is caused because Tungsram originally had three valve/tube factories in London, one being the 'British Tungsram Radio Works', in West Road, Tottenham. The brief entry in Graces Guide states that 'British Tungsram' was taken over by Philips/Mullard in 1952. It apparently continued to sell valves and eventually semiconductors under the brand 'TUNGSRAM', which implies that semiconductors marked 'TUNGSRAM' may not be Hungarian. Such devices cannot, however, bear the Tungsram logo. I have created a separate web page for British Tungsram.
Thanks to Miklós, a correspondent and fellow enthusiast, I have scans of a number of early Tungsram data catalogues, the earliest dated 1960. It includes some semiconductor diodes and transistors, details below.
Miklós has also sent me information about the history of another Hungarian semiconductor: Konverta Egyenirányító Gyár (Konverta Rectifier Company). As an independent state-owned company in the 1950s, Konverta was given the task of taking over the production of germanium and silicon alloy rectifiers as it was already in charge of selenium rectifier production. However, development of the germanium type was placed in the Bródi Laboratory of Izzó (Short name of Egyesült Izzó Ltd, the official name of Tungsram) led by Dr. Iván Szép. The TKI (An other development company) was commissioned to develop silicon rectifiers, with deadlines of 1-2 years later than for germanium devices. Production of prototyped germanium diodes began in 1960-61. Konverta was merged into Tungsram in January 1963.
If you can provide more detail about Tungsram or Konverta germanium devices, please
One source of information about early Tungsram devices is an article by Simoncsics László which was published in the Hungarian magazine 'Radiotechnika' in 2016. In one paragraph he says that 'Radiotechnika' started reporting on semiconductors in 1957. He goes on to say that Tungsram's first transistors were copies of the USSR type П6, made from about 1955.
My scanned Tungsram data catalogue for 1960 lists five transistors: P13, P13A, P13B, P14 and P15. These use the same outline as the P6 but were Tungsram development, not copies of USSR types. P6 is not listed.
There are images of some of these devices on the Web. The Orionette 1004 radio uses two P14 as AF amplifiers and a pair of P6 as output transistors. (Interestingly, that page lists the output transistors as 2P6, suggesting that a matched pair was sold). The P13 is shown on the radiomuseum site.
The images show two variants of P13B in an encapsulation that is very similar to early USSR transistors. I don't know why there is just a letter T rather than the Tungsram logo. I suspect strongly that the number under the part code on one is a date code in the format month-year, so that P13B coded 88 was made in August 1958. I don't know whether the black-painted one, kindly donated to me by Erno in Hungary, is earlier or later.
I would like to obtain examples of these P types, the P6x ones in particular. If you know where I might get some, please
My scan of the Tungsram catalogue for 1963 contains some P-series types in what was to become Tungsram's standard outline for low-power transistors, a metal cylinder similar to SO-2 or TO-1.
The catalogue contains:
The original P types are not listed, so these must have superseded them. My image shows the P13AT
Tungsram made germanium transistors in the Philips/Mullard OC series, but for most of them they added 1000 to the original part number. A Hungarian data book (7.6MB pdf) from 1960 by Házman and Hrabál lists the following:
I believe that the black-painted ones are the earliest and I am seeking a black example of OC1044.
Tungsram tubes and transistors are often printed with a proprietary two-character date code. The values are shown here, although the case (upper/lower) of the letter seems to be sometimes wrong. My OC1016 above is coded r9 which I believe to be September 1963 (code R9, there is no r9 in the table).
Tungsram made other transistors equivalent to OC types, starting later than 1960. The 1963 Tungsram catalog lists:
- OC1070, OC1071, OC1072.
The 1966 Romanian databook 'Catalog de Dispozitive Semiconductoare' by Veronica Vătăşescu and Şerban Epure, which you can download from the Web, lists
- OC1070, OC1071, OC1072, OC1074, OC1075, OC1076, OC1077, and OC1079.
The 1966 Romanian databook mentions a Tungsram type OC1080 in a brief note. However no such type exists in early Tungsram databooks.
I am seeking black versions of OC1045, OC1070, and OC1079. If you can help with that, please
This image shows a pair of Tungsram transistors clearly marked OC44F. I'm grateful to Erno in Hungary for donating these, however, neither he nor I can find this type in any data book! If you can provide data, please
Considering now the pro-Electron numbering, I have a Tungsram catalogue for 1966 that lists the following germanium types:
Thanks to Erno I know that the code HM that appears on these transistors means Honvédelmi Miniszterium = Ministry of Defence.
The ASZ versions with 1000 added have lower maximum ratings than the 'original' types. Thanks again to Erno for these.
The Tungsram 'Handbuch der Transistoren' 1969 has added:
On the left is what appears to be a Tungsram ASY78T, although the logo does not seem quite right. This type is not found (nor is any other ASY type) in any Tungsram documentation of which I am aware. If you know where I can find information aboutthis device, please
Considering now early diodes, I turn again to the Hungarian data book from 1960. It lists two series of germanium point-contact diodes by Tungsram:
These do not appear in the Tungsram catalogue, and I do not know what they look like. The naming makes me wonder if they are copies of USSR devices, if they were in fact manufactured.
If you know where I can find information about, or examples of, these GD diodes, please
These are all glass axial point-contact diodes and I believe that they are equivalent to Telefunken types without the '1000' added, for example OA1150 is equivalent to Telefunken OA150. These are shown in the images below, which show early examples with a coloured decal on the body; later examples just have black printing on the glass.
I also have some OA1154 without the Q suffix but with a green decal: I would be interested in original data for this type. The type OA1161 was sold in matched pairs denoted 2-OA1161, as shown by the rightmost image above. Possibly other OA types were too, but I have no data for such pairs. If you do, please
Tungsram documents list three more OA types: the gold-bonded diodes OA1180, OA1182 and OA1182D. My images show the first of these with a rather fetching purple decal, and a type OA1182A that I cannot find listed.
I am seeking examples of OA1182 and OA1182D with decals on the body (rather than later examples with printing on the glass), plus original data for OA1182A. If you know where I can get any, please
Tungsram also made glass-bodied point-contact types in the GA and GAZ series, but the 1960 Hungarian data book does not list them. These are Eastern European series.
Tungsram's 'Electron Tubes and Semiconductors' from 1976 lists the pro-Electron types:
I have a scan of a Tungsram diode databook from 1966 that includes:
The 1960 Hungarian data book has sections on germanium junction diodes and silicon diodes, but there are no Tungsram types listed.
Diodes from Konverta are harder to find and I'm grateful to Erno for sending me several types. I know that they made:
As with my SIEK-4, later production may be branded Tungsram, or even possibly HWF, because in 1962 Konverta transferred the technology for the production of germanium rectifiers to the Frankfurt(Oder) semiconductor factory in the GDR free of charge.
There are higher-numbered diodes in the Tungsram SIEK series, and indeed reverse polarity versions with a suffix 'R'.
I would be interested to obtain Konverta-branded examples of any GDK diode, to complete my line-up.
Of course Tungsram went on to make other silicon diodes and transistors, and indeed integrated circuits, but I shall not show those here.