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. 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 USSR devices is tricky, although most examples do bear a logo, many of which are listed here. Moreover, 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 (SRI) Number 35". Manufacture was initially kept secret and the first devices were used by the military. Sometimes devices have no manufacturer's logo, just a rhombus that denotes that they meet military quality standards.

Svetlana logo 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 by Andrew Roubtsov 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 on many pages (why not?). It contains data sheets for many of the early types and much of what I state below is derived from it.

Another important source of information is the Livejournal of Aleksei Pogorily, in Russian of course, which has pages on early transistors and diodes. (Those two hyperlinks pass the content through Google translate to render it in English).

Another source of data are the US National Bureau of Standards books by Charles Manson entitled "NBS TABULATION OF PUBLISHED DATA ON SOVIET ELECTRON DEVICES". I have found several of these downloadable on the Web, dated from 1963 to 1971.

Most USSR transistor types had a number of suffixes (often many), for example П1A, П1Б, 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


I have come across an interesting document on the Web: "Translations on Eastern Europe Scientific Affairs No 569", dated 12 January 1978, which contains the article "SEMICONDUCTOR DESIGNATION SYSTEMS DESCRIBED". Amongst those of other countries, it describes the semiconductor numbering systems used by the Soviet Union.

  • As you might expect, the very earliest types were idiosyncratic; I mention them below.
  • Devices made from 1959 to 1963 conform to State Standard 5461-59.
    • The earliest of these have an initial П (Latin P) for transistors or Д (Latin D) for diodes.
    • This is followed by a number belonging to defined groups.

    For transistors:

    1 - 100 low-power germanium low-frequency

    101 - 200 low-power silicon low-frequency

    201 - 300 power germanium low-frequency

    301 - 400 power silicon low-frequency

    401 - 500 low-power germanium high-frequency

    501 - 600 low-power silicon high-frequency

    601 - 700 power germanium high-frequency

    701 - 800 power silicon high-frequency

    For diodes:

    1 - 100 point-contact germanium

    101 - 200 point-contact silicon

    201 - 300 junction silicon

    301 - 400 junction germanium

    401 - 500 mixer microwave

    501 - 600 multiplier

    601 - 700 video detector

    701 - 749 parametric germanium

    750 - 800 parametric silicon

    801 - 900 stabilitrons

    901 - 950 varicaps

    951 - 1000 tunnel diodes

    1001 - 1100 rectifier columns

    • This may be followed by an optional letter denoting the development variant, following the order of the Russian alphabet (А,Б,В,Г, etc.).
    • A few have one or two specialised trailing letters.

    My interest primarily lies with the above types, and I will not show many later ones.

    • A number of members of the П series of transistors were enhanced and renamed the МП varieties, which means 'modernised P'. This prefix was given to devices that were the result of improvements of the old transistors from the П series. Usually this meant replacing a hot-rolled package by a cold-welded one. So МП102 is electrically equivalent to the older П102 (it has the same crystal) but in a new package. I suspect that some quite low-numbered МП types exist for which there is no П-series predecessor.
  • Devices made from 1964 to 1973 conform to State Standard 10862-64.
    • An initial letter or digit indicating the semiconductor material: Г (latin G) or 1 for germanium, K or 2 for silicon, and A or 3 for gallium arsenide. The digit versions have higher temperature tolerance; a correspondent has told me that this means that they were intended for military use.
    • A second letter designating the type of device: Д (Latin D) for diodes, Т for transistors, В (Latin V) for varicaps, А for microwave diodes, Ф (Latin F) for photo-devices, Н (latin N) for uncontrolled multilayer switching devices (dynistors), У (latin U) for controlled multilayer switching devices (thyristors), Й (Latin I) for tunnel diodes, С (latin S) for stabilitrons, Ц (latin Ts) for rectifier columns and units.
    • These are followed by a number designating the purpose or electrical properties of the semiconductor device. As with the older standard, the numbers are grouped into ranges with defined categories but I shan't list them here.
    • Lastly there is always a letter denoting the development variant, following the order of the Russian alphabet (А,Б,В,Г, etc.).
  • Devices made from 1974 conform to State Standard 10862-74, but the document does not describe this. It is clearly an update to 10862-64.

wanted transistor

Research on transistors started in the USSR in about 1950, and various experimental point-contact transistors were made in several laboratories. In late 1953 a range of devices numbered КС1 to КС8 was released for domestic use at some level. I have no information how they were used, and I cannot find an image of any on the Web. 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 transistors were germanium point-contact types С1 and С2 (Latin S1 and S2) which use a smallish cartridge case rather similar to those made in other countries.

С1 exists with six suffixes: А, Б, В, Г, Д and Е. This С1А was made by SRI no 35, which became Pulsar and exists to this day.

S1A transistor

С2 exists with four suffixes: А, Б, В and Г. This С2А was also made by SRI 35 Pulsar, although I have another made by ПЛУТОН(Pluton).

C2 transistor

These were followed by С3 and С4 (Latin S3 and S4) in small green flat cans with a pronounced flange like the П6 below (except for colour). These are point-contact devices electrically identical to С1 and С2 respectively but in more modern encapsulation. According to www.155la3.ru these are rarer than the original С1 and С2. They have the same suffixes as the С1 and С2. My image shows a С3Б dated August 1957.

There is also some evidence of the existence of a type С5, allegedly for military use. I have not found any images of this, but would like to.

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,

S3B transistor

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

Prototype versions had different part numbers: КСВ1, КСВ2 etc., I would be very interested to obtain examples of these, if you know where I might get any, please

P1A transistor

The П1 has eight suffixes, А to И (there is no suffix З as that has a special meaning). This image shows a П1А and a П1Б, both made by Svetlana.

P2A and P2B transistors

The П2 has only two suffixes: П2А and П2Б. This image shows a П2А made by Pulsar with the part number and date stamped into the lead and a П2Б in its original paper envelope with characteristic data values, some handwritten. I have not yet deciphered these. This is a high-voltage type, allowing Vce up to 100 volts.

P3A transistor

Next in number is the П3 (Latin P3), also germanium PNP from 1955, similar in construction to the П1 and П2, but in a longer case with large fins of about 1 inch diameter allowing greater power dissipation. It has three suffixes: А, Б, В. This was the only device to use this shape. My image shows a П3А made by Pluton.


Then comes the П4 (Latin P4), a 5 amp germanium PNP power transistor in a cylindrical hat-shaped can about 3cm in diameter, produced from about 1957. It is painted black, and may have a white military star printed on top. Early examples have wire leads crimped onto the three pins but later ones have solder tags instead. Again this was the only device to use this shape. It comes in suffixes А to Д (5 values) plus П and У, often with an extra Э (Latin 'E') suffix that this page states indicates the existence of an internal metal screen to protect the crystal during welding of the case. My image shows an fairly early example П4В made by Pluton and dated 2-62, which has threads in two of its mounting holes as described on that page. The П4 is often offered on eBay: the device was very long-lived, until the 1980s.

P4V transistor

In addition to the big hat-shaped П4, there is a smaller variant in a more modern case with a second suffix М. (Shown on the right is П4БМ, latin P4BM). It has suffixes А to Д. It has no mounting holes, but its specification allows even higher collector current than the regular П4, so I suspect a clamping ring should be used. According to this page, in 1965 these were renamed П216 and П217 with various suffixes.

P4BM transistor

There is another unusual variant of the П4 that I am seeking: the rare type МП4 in the same large hat-shaped can. It has suffixes А and Б at least. If you know where I might get examples of this, please

wanted MP4 transistor

P5V transistor

The next type is the П5 (Latin P5), which apparently is a copy of the Mullard OC70 and OC71 germanium PNP types, to the extent that it originally had a glass case, but this caused problems and so it was changed to metal. This is quite a small device intended for use in hearing aids, miniature radio receivers, etc. operating at low voltage (1-5 V). It has five suffixes А, Б, В, Г, and Д.


The П series carries on with germanium PNP type П6 (Latin P6) in a small black 'top hat'. This was developed in 1955 as a replacement for the unreliable П1, using a more advanced welded case. It has suffixes А, Б, В and Г. My image shows a Svetlana П6А. However П6 did not exist for long, being itself replaced by П13-П15.

P6A transistor

П7 (Latin P7) is another 'miniature' type in the same case as П5. Pogorily says it was only produced for a short time and http://www.155la3.ru does not show it. If you know about it or have any for sale or trade/exchange, please

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

wanted transistor

P8 transistor

The П series continues with П8 (Latin P8), which originally was a large PNP power transistor that became П201 (Latin P201). The part number П8 was re-used for a small NPN germanium low-power type. As in my image, this has no suffixes.

wanted transistor

П8 is followed by П9 to П11 (Latin P9 to P11) all NPN low-power germanium in the small black 'top hat'. These are complementary to П13 to П15А. П9 comes with no suffix and the suffix А (shown), П10 has three versions: no suffix, suffix А and suffix Б and П11 has two versions: no suffix and suffix А.

I believe that МП9 (latin MP9) is the lowest-numbered of the 'modernised' МП range that use the cold-welded case (see below), although there is some information that suggests a МП8 (latin MP8) may exist. I do not have any examples of either.

I am seeking examples of all of these types.

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


Then comes П12 (Latin P12), a germanium PNP IF/RF type, for which early examples use a largish elongated can of oval cross-section like early US types. Later versions use the standard small round 'top hat' can. It has no suffixes.

I wish to obtain examples of П12 for my collection, both shapes. 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 to P15 transistors

This is followed by П13 to П15 (Latin P13 to P15) in the black tophat, low-power germanium PNP types, as shown. These are improved versions of the П6. As well as no suffix, variants are suffix А and suffix Б, the latter denoting low noise varieties. There is also an odd П13К. My examples are dated 1962 and 1964.

MP15 transistor

Here is a Svetlana МП15 dated Decemeber 1963. The leading М denotes that this is is a 'modernised' type and the image shows how the cold-welded case differs from the previous 'top hats' : there is an obvious base cylinder with the weld flange partway up the body. However, as the images below show, some later P-series types were, anomalously, fabricated in the cold-welded case, and some in both types.


They are followed in 1959 by П16 (Latin P16) also in the black tophat, a germanium PNP type intended for logic switching circuits of relatively low speed. Variants are П16А (shown) and П16Б.

P16A transistor

P17 transistor

Oddly, the next pair in the series, П17 and П18 (latin P17 and P18), revert back to the early co-axial shape like П1. Pogorily lists both as having three variants: no suffix, А and suffix Б. He says they were short-lived and were replace by П25 and П26. My image shows a Svetlana П17А. (It has the part number stamped into the metal ribbon leads).

I wish to obtain examples of П18 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.


П19 (Latin P19) is, according to Pogorily, another rare miniature type like П12.

I wish to obtain examples of П19 for my collection. If you have any for sale or trade/exchange, please

wanted transistor

П20 and П21 (Latin P20 and P21) are germanium PNP tophats again, supporting higher current than previous members of the series. The image shows a П20 dated Dec 1963 and a П21А dated June 1965. Pogorily lists no-suffix plus suffixes for П20 from А to Д and for П21 from from А to Е.

П22 and П23 (Latin P22 and P23) were, according to Pogorily, produced for a long time but are uncommon.

I wish to obtain examples of П22 and П23. If you have any for sale or trade/exchange, please

P20 and P21 transistors

I also show an МП21Г (latin MP21G). Of course, it uses the 'modernised' cold-welded encapsulation.

MP21G transistor

wanted P24 transistor

П24 (Latin P24) is a rare miniature type like the П5 (Latin P5) above.

I wish to obtain examples of П24 for my collection. If you have any for sale or trade/exchange, please


П25 and П26 are germanium PNP high-voltage transistors that were manufactured over a long period in the original 'top hat' case. They both had three versions: no suffix, suffix А and suffix Б.

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

wanted P25 transistor

P28 transistor

П27 and П28 (Latin P27 and P28) are germanium PNP low-noise transistors for the input stages of AF amplifiers, apparently only produced in the 'modernised' cold-welded case. Why these were not called 'MP' types is unknown to me.

I wish to obtain examples of П27 for my collection, ideally old ones. If you have any for sale or trade/exchange, please


П29 and П30 (Latin P29 and P30) are germanium PNP low-voltage mid-frequency transistors with increased performance for pulse circuits, made from about 1967 and 1973 respectively. My images show them in the 'modernised' cold-welded encapsulation. My П30 has a late date of 1987. П29 comes with no suffix and suffix А, П30 has no suffixes.

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

P30 transistor

wanted P31 transistor

П31 to П34 (Latin P31 to P34) were developed but not issued commercially. П33 and П34 are symmetrical transistors.

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


П40 and П41 (Latin P40 and P41) are non-military versions of the П15. There also should exist a П39 but I have not seen an example of it. That page on www.155la3.ru shows the first ones in the older hot-welded 'top hat', plus ones which are in the later cold-welded can like my example of a P40A+ dated 9-73. (The plus signifies a tighter gain control). These should really be named as MP types, and in fact those do exist as I show just below. The П40А seems to be the only suffix letter.

I wish to obtain examples of these in the older 'top hat' shape. If you have any for sale or trade/exchange, please

P40A+ transistor

On the right I show a nice Svetlana МП41 dated September 1965. This seems to have been quite a common type.

MP41 transistor

wanted P42 transistor

П42 (Latin P42) is a rare pulse transistor, the civilian version of П16А. It is found in both outlines (hot- and cold-pressed), and with suffixes

I wish to obtain examples of П42 for my collection. If you have any for sale or trade/exchange, please


The П series then jumps to the first range of Soviet silicon junction transistors, in theory П101 to П200 (latin P101 to P200), in 1956. Pogorily lists these as having been made:

  • П101 to П103 : low-power NPN silicon alloy transistors that were produced over a long time.
  • П104 to П106 : low-power PNP silicon alloy transistors that were produced over a long time.
  • П108 to П110 : low-power NPN silicon alloy transistors that were produced only briefly.

There may be other higher-numbered ones but there is little information. The image shows a П106 made by Pulsar in 1960 in the old hot-welded 'top hat' case.

I wish to obtain examples of П101 to П105 for my collection. If you have any for sale or trade/exchange, please

P106 transistor

The П series then proceeds in jumps through П200, П300, П400, etc, each of which contains a small number of transistors.


P203E transistor

The П200 types are germanium AF power transistors, including the enormous П207 and П208. My image shows a П203Е branded Электроника (Electronika) from Voronezh.

I wish to obtain examples of the П207 and П208 for my collection. If you have any for sale or trade/exchange, please


The П300 silicon types seem to come in two groups: П302 to П306 are medium-power types in a mid-sized round can (П306 shown), and П307 to П309 are low-power devices in the small round flanged can.

P306 transistor

The П400 series types are germanium high-frequency transistors in several different packages.

P401 transistors

The group П401 to П403 were the first Soviet diffusion-alloy transistors, developed in 1956-1957. This image shows the П401 in both the original П-series small 'top hat' dated 1962 and the МП-series cold-welded case dated 1964.

P411A transistor

The bizarre-looking П410 group includes the П411А and П418Г shown. These apparently co-axial transistors are very high frequency devices.

P405A transistor

This tall oval П405А is listed in Manson's book from 1963 as a germanium PNP Surface Barrier Transistor. I believe it to be rare.


The П500 types are silicon low-power high-frequency, in a taller version of the cold-welded can, with three leads in a line. Pogorily lists only П501 to П505 with few suffixes. My image shows П501А. They are hard to find so if you have any for sale or trade/exchange, or know where I might get some, please

P501A transistor

P606A transistor

The П600 group comprises germanium medium- and high-power high-frequency examples. My example shows a П606А.


The П700 series, such as this П702, are high-power high-frequency silicon transistors.

P702 transistor

GT308B transistor

As I state at the top, the later GT and 1T series are also germanium transistors, but I don't intend to show any except this ГТ308Б (latin GT308B) fabricated in the cold-welded case. It is a diffused germanium PNP general-purpose transistor.


Now let's turn to diodes.

There are some inconsistencies in the information about the first semiconductor diodes made in the USSR. Disregarding copper-oxide and selenium rectifiers, it seems likely that the first were point-contact diodes used as detectors for radar. Some Web pages state that they were copies of German devices such as the Telefunken ED702 that I show elsewhere. Those are silicon diodes, however, other articles state that the first USSR types were germanium.

My image shows the ДК-В1 (latin DK-V1) which is a silicon type that was manufactured from the 1940s into the 1980s. Like many radar diodes, it is supplied inside a lead sheath to protect against damage from static electricity.

DK-V1 diode

However, Pogorily states that the oldest USSR diodes were the series ДГ-Ц1 to ДГ-Ц17 (latin DG-C1 to DG-C17) of germanium point-contact mixer diodes. (He does not mention selenium or copper-oxide rectifiers).

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

wanted transistor

Pogorily also describes an early group of germanium junction rectifiers ДГ-Ц21 to ДГ-Ц27 (latin DG-C21 to DG-C27) which were made from about 1956 onwards. The image shows a ДГ-Ц24 dated 1959.

DG-C24 diode

D2V diode

After 1963, some point-contact diodes in the standard series use a typical glass encapsulation, but with the USSR metal ribbon connectors as shown in this image of a Д2В (latin D2V). The glass is unprinted and the part number and date are stamped into the ribbon leads, and often a diode symbol showing the polarity.


According to Pogorily the ДГ-Ц2n rectifiers suffered from the case being poorly made and they were soon replaced by germanium medium-power rectifiers like this Д7Ж. (This last letter has no direct Latin equivalent, it is usually translated as 'ZH' or 'ZHE' but sometimes 'J'). Despite what my databook says I am sceptical that these are point-contact diodes because of the case shape.

D7J diode

D303 diode

There are also moderately high-power rectifiers in stud packaging such as this germanium Д303 (latin D303), one of the series Д302 to Д305.


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

USSR photodiode

The USSR made a series of photodiodes ФД1, ФД2 etc. (Latin FD1, FD2 etc) of which the earliest members are germanium. I only have the ФД2 and ФД3-A shown. If you know where I can find others, especially ФД1 , please






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