Production of semiconductors in the former Soviet Union started in about 1947, and like most countries the first devices were point-contact diodes used as detectors for radar. They were initially based on German devices and used germanium as the active semiconductor. In the 1950's work moved on to point-contact transistors, and quickly on to junction types, and then silicon transistors.

Understanding the manufacturers of Soviet devices is slightly complicated, although most examples do bear a logo. However, in a communist country the means of production are controlled by the state. Most technology manufacturing facilities were designated by a number, for example "Scientific Research Institute Number 35". Manufacture was initially kept secret and the first devices were used by the military. Finally, as with some other countries, there was a blurring between research facilities and industrial manufacture.

Svetlana logo Perhaps the best known manufacturer is Svetlana, whose logo is shown on the right. This organisation, based in St.Petersburg, is one of the oldest manufacturers of vacuum tubes in the world, and still exists today. There are a number of others, such as Pulsar, Istok, and more.

There is a superb site on the Web that describes these early devices, transistors and diodes. However it is in Russian and the various browser translation options do not work (why not?). It contains data sheets for most of the early types. Most transistor types had a number of suffixes (often many), for example C1A, C1Б, etc. Of course, all part numbers are written in the Cyrillic alphabet.

I do not possess all the transistors described below, in fact I am seeking many of them. It is noted in the text where I am seeking examples of any particular type: if you have some for sale or exchange, please


The first semiconductors made in the USSR were germanium point-contact diodes in a screw-thread cylindrical shape used as detectors for radar. These were possibly copies of German devices. My image shows the DK-V1 (Cyrillic DK-B1) which was manufactured from the 1940s into the 1980s. Like many radar diodes, it was supplied inside a protective lead sheath: I am not sure why, as there is no risk of damage from static electricity.

DK-V1 diode

wanted transistor

The initial experimental transistors appear to have been numbered KC1, KC2 etc or alternatively COP1 to COP8. (This may be a confusion between Cyrillic and English). I do not even know what these looked like. Needless to say I would be very interested to obtain these for my collection, so if you can provide information or any example, please

Я был бы очень заинтересован, чтобы получить примеры любой из этих для моей коллекции. Если у вас есть для продажи или торговли / обмена, пожалуйста,


The first production transistor was type S1 (Cyrillic C1), a point-contact type in a smallish cartridge case as shown, rather similar to those made in other countries. This S1A was made by SRI no 35, which became Pulsar and exists to this day.

S1A transistor

C2 transistor

Type S2 (Cyrillic C2) was also a point-contact transistor, in the same cartidge case. My example was also made by SRI 35, although I have another made by ПЛУТОН(Pluto).


These were followed by S3 and S4 (Cyrillic C3 and C4) in small green flat cans with a pronounced flange like the P6 below (except for colour). They were point-contact devices electrically identical to S1 and S2 but in more modern encapsulation.

I would be extremely interested to obtain examples of any of these for my collection. If you have any for sale or trade/exchange, please

Я был бы очень заинтересован, чтобы получить примеры любой из этих для моей коллекции. Если у вас есть для продажи или торговли / обмена, пожалуйста,

wanted transistor

P1A transistor

The first junction transistors that the Soviet Union made are the types P1 (П1) and P2 (П2) from Svetlana and possibly other manufacturers starting in 1955. They used a co-axial construction with the emitter and collector at opposite ends and the base connection in the middle. Several suffixes were used: the image shows a P1A. They had metal ribbon leads and the part number and date were often stamped into them.


This image shows a P2B in its original paper envelope with characteristic data values, some handwritten. I have not yet deciphered these.

P2B transistor

P3A transistor

Next in number is the P3 (П3), also from 1955, similar in construction to the P1 and P2, but in a longer case with large fins of about 1 inch diameter allowing greater power dissipation. This was the only device to use this shape. My image shows a P3A.


Next in number again is the P4 (П4), a 1 amp power transistor in a large cylindrical hat-shaped can. It is painted black, and may have a white military star printed on top. It comes in several suffixes, all with an extra Cyrillic 'Z' (З) on the end such as the P4DZ (П4ДЗ) shown. My example is branded Электроника (Electronika) from Voronezh, with a logo that looks like a sine-wave in a diamond. The P4 is often offered on eBay. I'm not sure when production started, but the device was very long-lived.

P4A transistor

P5V transistor

The next P type is the P5 (П5), quite a rare type in a construction similar to the Mullard OC types, and also painted black, although the can is metal rather than glass. NB image is a close-up, this is quite a small device.


The P series carries on with P6 in a small black 'top hat' as shown in my image of a P6A.

P6A transistor

I believe there is a P7, but I have not found data on it. I suspect that it is another co-axial type. If you know about it or have any for sale or trade/exchange, please

Я не знаю, если там был Р7 , я не нашел на нем данные . Я подозреваю, что это может быть еще один тип коаксиальный . Если вы знаете об этом , или есть какие-либо для продажи или торговли / обмена, пожалуйста, свяжитесь со мной.

wanted transistor

wanted transistor

The P series continues with P8 to P11 all in a small black 'top hat' like my P6A.


Then comes P12 for which early examples use a largish elongated can of oval cross-section like early US types. Later versions use the standard small round can.

I would be interested to obtain examples of early-shape P12 for my collection. If you have any for sale or trade/exchange, please contact me

Мне было бы интересно получить примеры раннего формы P12 для моей коллекции . Если у вас есть для продажи или торговли / обмена, пожалуйста ,

wanted transistor

P13 transistor

This is followed by P13 to P16 in the black tophat, as shown by my example of a P13.


Oddly, the next pair in the series, P17 and P18, revert back to the early co-axial shape like P1. My image shows a P17.

I would be interested to obtain examples of P18 for my collection. If you have any for sale or trade/exchange, please

Мне было бы интересно , это получить примеры P18 для моей коллекции . Если у вас есть для продажи или торговли / обмена, пожалуйста, свяжитесь со мной.

P17 transistor

wanted transistor

There was apparently no P19, and P20 and P21 are tophats again, followed by P24 that looks like the P5. At some point the black painting ceased, so some types are found in both black or bare metal versions.

I would be interested to obtain examples of these for my collection. If you have any for sale or trade/exchange, please


The P series jumps from about P42 to the first series of Soviet silicon junction transistors, P104 to P106, in 1956. There are also P101 to P103 but I'm not sure how they fit in.

I would be interested to obtain examples of any of these for my collection. If you have any for sale or trade/exchange, please

P106 transistor

The P series then proceeds in jumps through P200, P300, P400, etc, each of which contains a small number of transistors.


P203E transistor

The P200 types are power transistors, including the enormous P207 and P208. My image shows the P203E branded Электроника (Electronika) from Voronezh.

I would be interested to obtain examples of the P207 / P208 for my collection. If you have any for sale or trade/exchange, please


The P300 types come in two groups: P302 to P306 are medium-power types in a mid-sized round can (P306 shown), and P307 to P309 are low-power devices in the small round flanged can.

P306 transistor

P400 series transistors

The P400 types are high-frequency transistors in several different packages such as the standard small 'top hat' P401 shown on the left of my composite image, the bizarre-looking P410 group (P411A shown in the middle) and some tall oval types (P405A on the right).


The P500 types were low-power, in typical small flanged cans.

wanted transistor

P606A transistor

The P600 group comprised medium power examples. My example shows a P606A.


There is also a P700 series, such as this P702, however I have no information on these.

P702 transistor

There are several later series of devices:

  • The MP series of germanium and silicon transistors
  • The GT series of germanium and silicon transistors
  • the KT series of silicon transistors
  • The 1T and 2T series of transistors

I am indebted to Andrey Roubtsov who has explained some of this:

The oldest USSR types were in the S (C) and P (П) series shown above. Then came MP (MП) which means 'Modernised P'. These names were given to devices that were the result of improvements of the old transistors from P series. Most often this meant replacing a hot-rolled package by a cold-welded one. So MP102 is electrically equivalent to the P102 (it has the same crystal) but in a new package.

Then in 1964 a new system of transistor names was started (however, devices developed before this date continued to be manufactured with the old names):

  • The first character means the type of semiconductor. 1 and G for germanium devices, 2 and K (from 'Kremniy') for silicon and 3 and A for gallium arsenide. If the first character is a digit that device is intended for military application, if the first character is letter, for civil and industrial equipment.
  • The next character is the letter T for bipolar transistors or the letter P (from 'Polevoy') for field-effect transistors. (My list above does not include FETs).
  • Then there is a three- or four-digit number. The first digit means:
    1. low power, low frequency transistors
    2. low power, medium frequency
    3. low power, high frequency
    4. medium power, low frequency
    5. medium power, medium frequency
    6. medium power, high frequency
    7. high power, low frequency
    8. high power, medium frequency
    9. high power, high frequency
    The remaining two (or three) digits indicate the serial number of the development, starting from 01.
  • And the last character, a letter, means different variations of electric parameters. Even if there is only one variant, the letter A is used.

So 1T116A, for example, means: germanium bipolar transistor for military application, low power, low frequency, sixteenth development, first variant of parameters.


wanted transistor

I recently came upon an interesting page on old Soviet diodes by Pogorily AI, in Russian of course. Here is a link to it, passed through Google translate. It states that the oldest ones were the series DG-C1 to DG-C17 (Cyrillic ДГ-Ц1 to ДГ-Ц17) of germanium point-contact mixer diodes.

I would be interested to obtain examples of any of these. If you know where I might get some, please


That Russian site also describes an early group of germanium junction rectifiers DG-C21 to DG-C27 (Cyrillic ДГ-Ц21 to ДГ-Ц27) which were made from about 1956 onwards. The image shows a DG-C24 dated 1959.

DG-C24 diode

D2V diode

According to that site, Russia then changed the naming system for their semiconductor diodes. The new scheme was:

  • D1-D99 - point-contact germanium diodes.
  • D101-D199 - point-contact silicon diodes.
  • D201-D299 - silicon junction diodes.
  • D301-D399 - germanium junction diodes.

Many of these diodes use a glass encapsulation with metal ribbon connectors as shown in this image of a D2V. The part number and date were usually stamped into the ribbon leads.


Apparently, according to that site, the DG-C2x rectifiers suffered from the case being poorly made and they were soon replaced by germanium medium-power rectifiers like this D7J. (That part number is a poor translation of Cyrillic П7Ж. This last letter has no direct English equivalent, it is often translated as 'ZHE'). However, there seems to be an inconsistency here: I don't believe that these are point-contact diodes.

D7J diode

D303 diode

And they made moderately high-power rectifiers in stud packaging such as this germanium D303.


Finally, I have seen some high-power germanium rectifiers in the VG series (Cyrillic ВГ) for sale on eBay but at an extraordinarily high price. If you know where I can find any at a reasonable price, please

wanted diode





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