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 Andrey Roubtsov on the Web that describes these early devices, transistors and diodes. However it is in Russian and it uses html frames that confuse the various browser translation options. You can usually guess the frame address if you want to get a translated version. It contains links to 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 "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 П1А, П1Б, etc., denoting versions of the same basic device. Of course, all part numbers are written in the Cyrillic alphabet. The plethora of suffixes creates a bit of a problem for the completist collector!

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

USSR transistors (and I believe other components too) often bear military designations, indicating compliance with military specifications or quality control. The most common ones are a white star in a circle, or the letters ВП which may be printed immediately after the part number, or sometimes elsewhere on the device body. ВП stands for "воинские подразделения" which translates as "military units" or "military mission" and is explained on this page of the Russian wikipedia. After translating and reading it I am still not completely clear what it means!

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.

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 was released for domestic use at some level. Web pages variously number them as either КС1 to КС8 or ТС1 to ТС7. I have no information on 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. Apparently production started in 1953, but examples dated earlier than 1956 are very rare.

С1 exists with six suffixes: А, Б, В, Г, Д and Е. This С1А was made by SRI number 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 and I have another made by Izmerital plant, now ПЛУТОН(Pluton).

C2 transistor

These were followed by С3 and С4 (Latin S3 and S4) in small green or black 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 these are rarer than the original С1 and С2. They have the same suffixes as the С1 and С2. 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.

S3A transistor
S3B transistor
S4 transistor

Above I show a black С3А in its original envelope; the device itself is unmarked. Also a С3Б that is painted green. Both were made by Izmerital/Pluton. I am still seeking С4.

I would be extremely interested to obtain examples of С4 or С5. If you have any for sale or trade/exchange, please

Мне было бы очень интересно получить примеры С4 или С5. Если у вас есть для продажи или обмена, пожалуйста,

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. All are suffixed and several suffixes were used. They have metal ribbon leads and the part number and date of manufacture are often stamped into them. These part numbers look as though they conform to State Standard 5461-59 but in fact they precede it.

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

The П1 has eight suffixes, А to И (there is no suffix З as that has a special meaning). The images below show that I am still seeking П1Д and П1И.

P1A transistor
P1B transistor
P1V transistor
P1G transistor
P1D transistor
P1YE transistor
P1ZH transistor
P1EE transistor
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 V-59 stamped into the lead and a П2Б in its original paper envelope with characteristic data values, some handwritten. I have not yet translated these. It has the part number and date 6-56 printed on the body. This is a high-voltage type, allowing Vce up to 100 volts.

P3A transistor
P3B transistor
P3V transistor

Next in number is the П3 (Latin P3), also germanium PNP, made by Pluton from 1955 and similar in construction to the П1 and П2, but in a longer case with large fins of about 2cm diameter allowing greater power dissipation. It has three suffixes: А, Б, В all shown above. This was the only device to use this outline.

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 early examples have wire leads crimped onto the three pins whilst later ones have solder tags instead. Again this was the only device to use this outline. It always has a suffix: one of А to Д (5 values) plus two rarities described below.

P4A transistor
P4B transistor
P4V transistor
P4G transistor
P4D transistor

The above are all dated between 1958 and 1962. Later production added a further suffix Э (Latin 'E') that indicates the presence of an internal metal screen to protect the crystal during hot-welding of the case.

P4AE transistor
P4BE transistor
P4VE transistor
P4GE transistor
P4DE transistor

The П4 is often offered on eBay: the device was very long-lived, until the 1980s.

There are two rare variants: П4П (Latin P4P) and П4У (Latin P4U). My image shows one of the latter dated July 1958. Documentation on these is hard to find. If you know where I can find an example of П4П or documentation of either type, please

P4U transistor

In addition to the big hat-shaped П4, there is a smaller variant in a more modern case with a second suffix М. It has suffixes А to Д : shown on the right is П4БМ, latin P4BM, dated December 1963. 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.

There is another very unusual variant of the П4 that I am seeking: the rare type МП4 in the regular large hat-shaped can. I don't know what the prefix М signifies. It has variants with suffixes А and Б at least. If you know where I might get an example of this, please

Я ищу примеры П4П и МП4. Если у вас есть для продажи или обмена, пожалуйста,

P4BM transistor

P5A 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 always has a suffix, either А, Б, В, Г, or Д. My images show the П5А and П5В.

I am seeking an example of the older, longer, glass version of П5. If you know where I can find any, please

Я ищу примеры более старой, длинной, стеклянной версии П5. Если вы знаете, где я могу их найти,

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 always has a suffix, either А, Б, В or Г. My images show a Svetlana П6А dated November 1958 and an unbranded П6В dated May 1957. However П6 did not exist for long, being itself replaced by П13-П15.

P6A transistor
P6V transistor

wanted 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 does not show it. It seems to be the first П-series device that did not have a suffix, so possibly it was the first to really conform to State Standard 5461-59. 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,

P8 transistor

The П series continues with П8 (Latin P8), which was originally 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, dated 1962, this has no suffixes.

The logo appears similar to the Svetlana 'winged C' but with a central 'T' instead, however I am reliably informed that the manufacturer is Planeta in Novgorod. They later changed logo to a broken circle with a dot inside.

I am seeking examples of the early large П8. If you know where I can find any, please

Я ищу примеры раннего большого П8. Если вы знаете, где я могу найти, пожалуйста,

P9A transistor
P10 transistor
P11 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.

MP9A transistor
MP10B transistor
MP11 transistor

I believe that МП9 (latin MP9) is the lowest-numbered of the 'modernised' МП range that use the cold-welded case, although there is some information that suggests an МП8 (latin MP8) may exist. I do not have any examples of either, but I have the МП9А made by Svetlana in 1964 and the МП10Б made by Planeta in 1969. My МП11 is later. The images show 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 outlines.

P12 transistor

Then comes П12 (Latin P12) from about 1957, 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 modernised МП-style cold-welded can, as shown in my example dated 1962. Probably because of this, there is no МП version of it. П12 has no suffixes.

wanted transistor

I wish to obtain an example of П12 in the oval can. If you have any for sale or trade/exchange, please contact me

Мне было бы интересно получить примеры раннего формы П12 для моей коллекции . Если у вас есть для продажи или торговли / обмена, пожалуйста,

P13 transistor
P14 transistor
P15 transistor

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. I have examples of all three dated 1962.

I wish to obtain an example of П13К. If you have any for sale or trade/exchange, please

Я хочу получить пример П13К. Если у вас есть для продажи или обмена / обмена,

P13B transistor
P14A transistor
P15A transistor

Here is a П13Б made in August 1963 by a manufacturer I'm unsure of: their logo is a horizontal transistor symbol. I suspect this is SRI35 Pulsar but their logo originally had a vertical transistor.

Also a П14А made in March 1963 by Planeta and a П15А with ВП qualification made in Nov 1964 by Voronez plant.

MP13 transistor
MP14A transistor
MP15 transistor

Here is a late МП13 made by Silicon Bryansk, a Svetlana МП14А dated October 1971 and an МП15 dated December 1963 from Planeta.

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. My image shows one made at Voronezh plant in 1964 and qualified for military use as indicated by the designation ВП that follows the part number. Variants are П16А and П16Б (both shown, the second also ВП qualified) from multiple manufacturers.

P16 transistor
P16A transistor
P16B transistor

Here's the modernised МП16А.

MP16A transistor

P17 transistor

Oddly, the next pair in the series, П17 and П18 (latin P17 and P18), revert back to the early co-axial outline like П1. Pogorily lists both as having three variants: no suffix, А and suffix Б. He says they were short-lived and were replaced by П25 and П26. My image shows a Svetlana П17А. (It has the part number stamped into the metal ribbon leads; you can also see the date 11-59).

I wish to obtain an example of П18. If you have any for sale or trade/exchange, please

Я хочу получить пример П18. Если у вас есть для продажи или обмена / обмена, пожалуйста,

П19 (Latin P19) is, according to Pogorily, another rare miniature type like П12. does not show it.

I wish to obtain an example of П19. If you have any for sale or trade/exchange, please

Я хочу получить пример П19. Если у вас есть для продажи или обмена / обмена, пожалуйста,

wanted transistor

П20 and П21 (Latin P20 and P21) are germanium PNP tophats again, supporting higher current than previous members of the series. Pogorily lists no-suffix plus suffixes for П20 from А to Д and for П21 from from А to Е. The image shows a П20 dated Dec 1963 and a П21А dated June 1965, both made by SRI35 Pulsar.

P20 transistor
P21A transistor

Here are the modernised versions. Of course, they use the cold-welded encapsulation.

MP20 transistor
MP21G transistor

wanted transistor

П22 and П23 (Latin P22 and P23) were, according to Pogorily, not produced for very long. A web search produces no images of them. There appear to be no МП versions of them, so they probably use the modernised cold-welded can.

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

Я хочу получить примеры П22 и П23. Если у вас есть для продажи или обмена / обмена,

wanted transistor

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

I wish to obtain an example of П24. If you have any for sale or trade/exchange, please

Я хочу получить пример П24. Если у вас есть для продажи или обмена / обмена, пожалуйста,

П25 and П26 (Latin P25 and P26) are germanium PNP high-voltage transistors that were manufactured over a long period in the original 'top hat' case, as replacements for the П2. They both have no suffix and suffixes А and Б. My П25 and П25А were both made by Svetlana in November 1961.

I wish to obtain an example of П26. If you have any for sale or trade/exchange, please

Я хочу получить пример П26. Если у вас есть для продажи или обмена / обмена, пожалуйста,

P25 transistor
P25A transistor

Here's the modernised МП25Б and МП26А.

MP25B transistor
MP26A transistor

P27A 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 МП types is unknown to me, and there appear to be no МП versions. П27 has three suffixes: none, А and Б while П28 has no suffixes. My П27А was made by Planeta in Sept 1972 and the П28 is a Planeta example from June 1972.

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 according to П29 comes with no suffix and suffix А, П30 has no suffixes. My unbranded П29 is dated August 1973 and the Planeta П30 is from November 1973. My images show them in the 'modernised' cold-welded encapsulation, I don't believe they were produced in the older outline or as МП versions.

P29 transistor
P30 transistor

wanted transistor

П31 to П34 (Latin P31 to P34) were developed but not issued commercially. does not show them. П33 and П34 are symmetrical transistors. No modernised versions exist.

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

Я хочу получить примеры этого. Если у вас есть для продажи или обмена,

P39B transistor

Types П35 to П39 (Latin P35 to P39) are somewhat enigmatic. Pogorily lists them in an aside rather than giving their details, which suggests that their production was unusual somehow. He says that П35 to П38А are "similar to П8 to П11А" and П39 is "similar to П13". Manson lists only the П39Б in the 1967 edition of his book, but in the 1970 edition he has П35, П36А, П37, П38, П39, and П39Б. However the 1971 edition has none of them. does not show them, and a Web search reveals no images of them.

I only have the П39Б shown on the left, made by SRI 35 (now Pulsar) in December 1964. Is it a co-incidence that this is the only one listed by Manson 1967?

I am seeking examples of П35 to П39, if you know where I can find any or you know more about these types, please

Я ищу примеры от П35 до П39, если вы знаете, где я могу найти какие-либо или вы знаете больше об этих типах,

MP38 transistor

There are modernised МП versions with all of these numbers, such as this МП38.

П40 and П41 (Latin P40 and P41) were made from the mid-1960s and are, according to Manson, "similar to П14 to П15A" whereas states they are non-military versions of the П15 and shows the oldest ones in the older hot-welded 'top hat', plus ones which are in the later cold-welded can like my example of a П40А+ dated 9-73. (The plus signifies a tighter minimum gain control). These should really be named as МП types, and puzzlingly those do exist as I show just below. As well as no suffix, both have suffix letter А and the П40 exists with suffix Б.

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

Я хотел бы получить примеры того и другого в старом наброске «цилиндра». Если у вас есть для продажи или обмена,

P40A+ transistor

On the right I show a Planeta МП40А+ from July 1971 (older than my П40А+!) and an unused Svetlana МП41 dated September 1965. This latter seems to have been quite a popular type.

MP40A+ transistor
MP41 transistor

wanted P42 transistor

П42 (Latin P42) is a rare pulse transistor made from about 1965, the non-military version of П16А. It is found in both outlines (hot- and cold-pressed), with no suffix and with suffixes А and Б.

I wish to obtain an example of П42. If you have any for sale or trade/exchange, please

Я хочу получить пример П42. Если у вас есть для продажи или обмена / обмена, пожалуйста,

MP42B transistor

There is also a modernised МП42. The image shows an unused Svetlana МП42Б dated April 1965.

The П series then proceeds in jumps through groups starting П101, П201, П301, П401, etc, each group containing different types of transistor as listed in the document described near the top of this page. Each group usually contains only a small number of different parts.

The П101 group comprises the first range of Soviet silicon junction transistors, in theory П101 to П200 (latin P101 to P200), in 1956. Pogorily lists the following 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 are few suffixes: П101А, П101Б, П103А and П108А. The images show a Svetlana П101 and a Pulsar П106 both made in 1960 in the old hot-welded 'top hat' case. I am seeking П108 to П110.

P101 transistor
P106 transistor

There are modernised versions of these, as this МП103 shows. There also exist МП111 to МП116 but I am unaware of the existence of previous П versions.

MP103 transistor

P201 transistor

The П201 group contains germanium PNP AF power transistors, made from 1958, including the enormous П207 and П208. Pogorily lists П201 to П217. My image shows an old П201 dated February 1959 from the Izmerital plant (now Pluton).

wanted transistor

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

Я хочу получить примеры П207 и П208. Если у вас есть для продажи или обмена,

The П301 group types seem to come in two subgroups: Pogorily lists П302 to П306 as medium-power silicon PNP types in a mid-sized round can (П306 shown) and П307 to П309 are low-power silicon NPN planar devices usually in the МП flanged can (П307А shown). However, early П307 to П309 come in a unique bell-shaped can, and late versions with an М suffix are found in a plastic case (!).

П314 and П322, according to Manson, are anomalous germanium PNP types; I have not seen examples or even images of them and am sceptical of their existence.

I wish to obtain examples of the П307 to П309 in the bell-shaped can. If you have any for sale or trade/exchange, please

P306 transistor
P307A transistor

The largish П401 group holds germanium PNP high-frequency transistors in a number of different packages. Pogorily lists П401 to П423.

P401 transistors

The subgroup П401 to П403 and П403А were the first Soviet alloy-diffused 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. However, the type numbers were not changed to МП for the modernised devices.

P405A transistor

The П404 and П405 (both also with suffix А versions) in a tall oval can are listed in Manson's book from 1963 as germanium PNP surface barrier transistors of 10 MHz and 30 MHz respectively. I believe them to be rare. My image is of a П405А made by SRI35-Pulsar in May 1958.

P407 transistor

The П406 and П407 are high-frequency versions of П12. They originally came in a tall oval can but changed to the standard modernised МП outline. I don't believe that МП versions were made.

wanted transistor

I am seeking the П406 and П407 in the tall oval can

The П408 and П409 are obscure but may also have used a tall oval can. I am seeking those too.

P411A transistor

The bizarre-looking П410 and П411 (both also with suffix А versions) are coaxial-type microwave transistors capable of 200-400 MHz.

wanted transistor

The П412 and П413 use the same can as П405 and also come in a small 'cigar tube' outline.

P415 transistor P416B transistor

П414 and П415 from 1961 (plus suffixes А and Б) use the old 'top hat' outline, and later the modernised outline. Again, the type numbers were not changed to МП for the modernised devices. They were superseded by П416 (various suffixes, my image shows П416Б) in the МП outline.

P417 transistor

П417 uses a taller cold-welded can with three leads in a line. It too is a germanium PNP RF amplifier. There is a suffix А version.

P418G transistor

П418 is also a co-axial microwave type up to 400 MHz. It seems to have suffixes Г, Е and И.

Pogorily says there is a П419 but he cannot locate data about it.

P420 transistor
P423 transistor

П420 to П423 (the last two also have suffix А) use the old 'top hat' outline, and later ones switch to the modernised outline. Again, the type numbers were not changed to МП for the modernised devices. This П420 was made by Alpha Riga in Sept 1963 and the modernised П423 by Alpha Riga in June 1964.

The П501 group types are silicon PNP low-power high-frequency, in the taller cold-welded can. Pogorily lists П501 to П505, all with suffix А versions and П502 also having suffixes Б and В. My images show П501А and П503 both made by SRI35-Pulsar in mid 1963.

P501A transistor
P503 transistor

P606A transistor

The П601 group comprises germanium PNP medium- and high-power high-frequency examples. Pogorily lists П601 to П609 (but no П603), with a few suffixes. My example shows a П606А.

P702 transistor

The small П701 series, such as this П702, are high-power high-frequency NPN silicon transistors. Pogorily lists only П701 and П702.

wanted transistor

Before the introduction of State Standard 5461-59, and to a lesser extent after it, a few USSR transistors were made that use a slightly different numbering system: simply a number (usually, but not always, 3xx) followed by a suffix. Pogorily does not mention these but a few are shown on I only have the 313А shown, dated January 1958, and I am seeking examples of a few others, with any suffixes, namely 316, 342, 343 and 347.

GT308B transistor

As I state at the top, the later GT and 1T series are also germanium transistors, following State Standard 10862-64. The number groupings are:

101 - 199 low-power low-frequency transistors

201 - 299 low-power medium-frequency

301 - 399 low-power high-frequency

401 - 499 medium-power low-frequency transistors

501 - 599 medium-power medium-frequency

601 - 699 medium-power high-frequency

701 - 799 high-power low-frequency transistors

801 - 899 high-power medium-frequency

901 - 999 high-power high-frequency

These types use several outlines, including the 'MP'-style can, but not the original hot-welded 'top hat'. I don't intend to show any except this ГТ308Б (latin GT308B) fabricated in the cold-welded case in 1975. It is a germanium diffused-junction PNP general-purpose transistor.

Now let's turn to diodes. I am indebted to A. Чечнев who has researched this area in detail and published his findings in the Russian magazine "RADIO" for April and May 2020.

The earliest types were silicon 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. They have part numbers like КД2-И10, КД2С10А, КД2С3А, КД6В10А and КД6В3Б. My image shows the ДК-В1 (latin DK-V1) which is a silicon type that was manufactured from the 1940s into the 1980s and was previously called КД2В10. Like many radar diodes, it is supplied inside a lead sheath to protect against damage from static electricity.

DK-V1 diode

The oldest germanium diodes were the series of point-contact mixer diodes ДГ-В1 to ДГ-В8 from 1951. These were released publicly as ДГ-Ц1 to ДГ-Ц8 (latin DG-C1 to DG-C8) and the series was later extended to ДГ-Ц17.

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

There are also some copper-oxide diodes to be found. My image shows the ВК7-1а (latin VK7-1a) which is a low-current type made from 1957 and used in instrumentation. There are other older copper-oxide and selenium types but I shall not show them.

VK7-1a diode

D2V diode

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

Type Д1 apparently does exist: it is listed in Manson's tables with seven suffixes. However I have never seen an example. If you know where I can get some, please

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. (Latin D1ZH or D1ZHE and sometimes translated as D1J). 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-current rectifiers in stud packaging such as this 150V 3A germanium Д303 (latin D303) made by the Saransk plant, one of the series Д302 to Д305.

I have seen some very-high-current germanium rectifiers in the ВГ series (latin VG) 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

This is an oddity. It's the only USSR diode that I have found that has the 'М' prefix. Д226 is a silicon rectifier with possible suffixes А, Б, В, Г, Д and Е according to Manson. However my image shows an МД226Б. If you know about diodes with the М prefix, please

MD226B 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 odd flat plastic ФД2 and the more conventional tubular ФД3-A shown. If you know where I can find others, especially ФД1 , please