The German company Valvo was an old and well-established company that made renowned vacuum tubes. Their history is not very well documented on the Web, at least not in English, but a starting point is this page on the German wikipedia (translated by Google), and some more detail is given on this Facebook page.
These reveal that the company was founded in 1924 in Hamburg, and in 1927 became part of the Philips group. Neither article mentions semiconductors in any detail, their focus being on vacuum tubes. However, the relationship between Philips and its subsidiaries Mullard (in England), Valvo (in Germany) and La Radiotechnique (in France) appears to have been quite free. (There was also Amperex in the USA, but this was essentially a sales channel). The subsidiaries had their own research facilities (of course Philips had major laboratories in Eindhoven) and may have been able to develop devices that went on to be manufactured across the group. If you know more about how this worked, please Apparently Valvo was split in the 1980s and sold in 1999.
Valvo did not normally print their logo on semiconductor devices, probably because of space limitations: they just printed the word VALVO in capital letters. I am seeking to buy or trade for germanium transistors and diodes made by Valvo, especially the types 100.O.C, OC10 to OC12, and OC50 to OC51, but also some others. More details are given below.
A possibly difficulty with identifying Valvo devices is that many came in small cartons clearly marked 'Valvo'. However the devices inside may be unbranded. This raises the question of whether they were really manufactured by Valvo, or whether they are Valvo-boxed Philips production.
The primary Valvo data book that I possess is the Valvo-Handbuch 'Halbleiterdioden und Transistoren'. I have copies dated 1958 and 1962. I also have a booklet 'Dioden Transistoren' dated 1960. I'm grateful to Gert who has sent me scans of the contents pages of several 1960s Valvo Taschenbuchs and the semiconductor Handbuch for 1965. I am interested in other original data books or sheets for any of their semiconductor devices.
If you know about them, or have have some devices for sale or trade, please
The earliest transistors made by the Philips group as a whole are described in several places on the Web, although the Philips pages on their company history seem to have disappeared, perhaps because of the change to NXP Semiconductors. On Google, there is a site by Mark Burgess that covers early Philips semiconductors, revealing that their first transistors were the point-contact types OC50 and OC51. It is unclear which manufacturers in the Philips group really made these and whether others simply marketed them: certainly Mullard made them, and I believe that Valvo did too.
I have a number of OC51 transistors that I believe were made by Mullard, and they have no branding. If you know about Valvo examples, or know how I can obtain Valvo OC50 or OC51, please
The first junction transistors made by the Philips group were the trio OC10 to OC12 in small plastic cuboids. Again it is unclear which manufacturers in the Philips group really made these and which simply marketed them, and again I have some and they are unbranded. I recollect that I saw some claimed to be Valvo production in the Deutsches Museum in Munich. If you know about Valvo examples, or know how I can obtain some, please
Valvo went on to manufacture the next set of transistors from the Philips group: the OC70 to OC72 AF amplifier types from 1954. My two OC70s are sealed in their original cartons and I don't want to open them. I would like to find a loose one for display purposes. If you know how I can obtain one, please
Another puzzle exists around the creation of Europe's first power transistor, the type 100.O.C. Mark Burgess states that this was 'released by Valvo in October 1954' and became the wider Philips group type OC15. In the USA it was marketed as the 2N115. I have the example shown: it bears no branding and all the printing on it is in English, including 'Semicond. Lab. Development Sample'. Consequently, I'm unconvinced that Valvo made this. I have no original Philips-group documentation for either 100.O.C. or OC15: it might help resolve the question. If you know how I can obtain some (or a scan of it), please
The first commercial power transistor in Europe was the OC16, in a stud package, released about 1956. It can be found branded Mullard and Valvo (shown), as well as unbranded, which I take as indicating Philips production in the Netherlands.
There exists also a more primitive version of the OC16 with leads emerging from the top. It is shown on my Mullard page. This is always unbranded in my experience but if you know of a Valvo-branded one, please
As I stated above, the oldest Valvo databook that I possess is 'Halbleiter - Dioden Transistoren' dated 1958. It lists the following types:
- OA5 germanium gold-bonded diode
- OA7 germanium gold-bonded diode
- OA31 germanium high-current junction diode
- OA70 germanium diode
- OA72 germanium diode
- 2-OA72 germanium diode pair
- OA79 germanium diode
- 2-OA79 germanium diode pair
- OA73 germanium diode
- OA81 germanium diode
- OA85 germanium diode
- OA86 germanium diode
- OA87 germanium diode
- OA91 germanium diode
- OA95 germanium diode
- OA200 silicon diode
- OA202 silicon diode
- OC16 germanium power transistor
- 2-OC16 germanium power transistor pair
- OC30 germanium power transistor
- 2-OC30 germanium power transistor pair
- OC44 germanium transistor
- OC45 germanium transistor
- OC65 germanium transistor
- OC66 germanium transistor
- OC70 germanium transistor
- OC71 germanium transistor
- OC72 germanium transistor
- 2-OC72 germanium transistor pair
- OC76 germanium transistor
- OC77 germanium transistor
I would be most interested to see earlier (pre-1958) Valvo databooks or sheets, either originals or scanned images. I would also like to obtain examples of interesting Valvo-branded types missing from my collection, particularly OA31, OA72, OA87, OC65 and OC66. If you know how I can obtain some, please
The 'Dioden Transistoren' booklet from 1960 adds more types:
- BA100 silicon all-purpose miniature diode
- OA9 germanium gold-bonded diode
- OA47 germanium gold-bonded diode
- OAZ200 - OAZ207 silicon Zener diode
- OC22 germanium power transistor
- OC23 germanium power transistor
- OC24 germanium power transistor
- OC26 germanium power transistor
- 2-OC26 germanium power transistor pair
- OC28 germanium power transistor
- OC29 germanium power transistor
- OC35 germanium power transistor
- OC36 germanium power transistor
- OC46 germanium switching transistor
- OC47 germanium switching transistor
- OC57 germanium subminiature transistor
- OC58 germanium subminiature transistor
- OC59 germanium subminiature transistor
- OC60 germanium subminiature transistor
- OC74 germanium output transistor
- 2-OC74 germanium output transistor pair
- OC75 germanium AF transistor
- OC79 germanium output transistor
- OC80 germanium switching transistor
- OC139 germanium NPN switching transistor
- OC140 germanium NPN switching transistor
- OC141 germanium NPN switching transistor
- OC169 germanium RF transistor
- OC170 germanium RF transistor
- OC171 germanium RF transistor
- OC200 silicon transistor
- OC201 silicon transistor
I would like to obtain examples of interesting Valvo-branded types missing from my collection, particularly OC46, OC57 to OC60, OC80, OC139 and OC141. If you know how I can obtain some, please
The Handbuch 1962 edition adds even more types, most now using Pro-Electron nomenclature:
- AAZ12 germanium gold-bonded diode
- AAZ13 germanium gold-bonded diode
- AAZ15 germanium gold-bonded diode
- AAZ17 germanium gold-bonded diode
- AC107 germanium transistor
- ADZ11 germanium power transistor
- ADZ12 germanium power transistor
- AF102 germanium RF transistor
- AF114 germanium RF transistor
- AF115 germanium RF transistor
- AF116 germanium RF transistor
- AF117 germanium RF transistor
- AF118 germanium RF transistor
- AF124 germanium RF transistor
- AF125 germanium RF transistor
- AF126 germanium RF transistor
- AF127 germanium RF transistor
- AFZ12 germanium RF transistor
- ASY26 germanium switching transistor
- ASY27 germanium switching transistor
- ASZ15 germanium power switching transistor
- ASZ16 germanium power switching transistor
- ASZ17 germanium power switching transistor
- ASZ18 germanium power switching transistor
- ASZ23 germanium switching transistor
- AUY10 germanium power RF transistor
- BA102 silicon miniature diode
- BA109 silicon miniature diode
- BCY10 silicon PNP AF transistor
- BCY11 silicon PNP AF transistor
- BCY12 silicon PNP AF transistor
- BCZ10 silicon PNP AF transistor
- BCZ11 silicon PNP AF transistor
- BCZ12 silicon PNP AF transistor
- BY100 silicon power diode
- BYY15 silicon power diode
- BYY22 silicon power diode
- BYZ14 silicon power diode
- BZZ10 - BZZ13 silicon miniature Zener diode
- OA90 germanium miniature diode
- OAZ208 - OAZ213 silicon Zener diode
- OC80A germanium transistor
- OC122 germanium RF transistor
- OC123 germanium RF transistor
I would like to obtain examples of interesting Valvo-branded types missing from my collection, particularly BCY10, BCY11, BCZ12, OC122 and OC123. If you know how I can obtain some, please
I have a copy of the contents page of the Handbuch for 1964 and it includes many more Pro-Electron types. The most interesting to me are those that still use the older idiosyncratic outlines:
- ASY31 germanium PNP switching transistor
- ASY32 germanium PNP switching transistor
I would like to obtain an example of ASY31 which seems to be rather rare. If you know how I can obtain one, please
It is interesting to compare Valvo's early range with that of Mullard. I maintain computer files that list all the types contained in my reference data books, both paper and electronic. I wrote some java software to generate this table by reading and processing my files for Valvo and Mullard. I only processed types starting with OA or OC, plus LDR and ORP. I added entries for types that I know to exist even though my databooks do not list them, this includes the early types OC10/11/12/50/51 for Valvo, which I strongly suspect do exist although I have no proof.
Type | Valvo | Mullard | Type | Valvo | Mullard | Type | Valvo | Mullard | Type | Valvo | Mullard | Type | Valvo | Mullard | ||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2-OA72 | ✓ | ✗ | OA91 | ✓ | ✓ | OAZ246 | ✗ | ✓ | OC57 | ✓ | ✓ | OC123 | ✓ | ✓ | ||||
2-OA79 | ✓ | ✓ | OA95 | ✓ | ✓ | OAZ247 | ✗ | ✓ | OC58 | ✓ | ✓ | OC139 | ✓ | ✓ | ||||
2-OC16 | ✓ | ✓ | OA200 | ✓ | ✓ | OC10 | ✓ | ✓ | OC59 | ✓ | ✓ | OC140 | ✓ | ✓ | ||||
2-OC20 | ✗ | ✓ | OA202 | ✓ | ✓ | OC11 | ✓ | ✓ | OC60 | ✓ | ✓ | OC141 | ✓ | ✓ | ||||
2-OC26 | ✓ | ✗ | OA210 | ✓ | ✓ | OC12 | ✓ | ✓ | OC65 | ✓ | ✓ | OC169 | ✓ | ✓ | ||||
2-OC28 | ✗ | ✓ | OA211 | ✗ | ✓ | OC16 | ✓ | ✓ | OC66 | ✓ | ✓ | OC170 | ✓ | ✓ | ||||
2-OC29 | ✗ | ✓ | OA214 | ✓ | ✓ | OC16R | ✗ | ✓ | OC70 | ✓ | ✓ | OC171 | ✓ | ✓ | ||||
2-OC30 | ✓ | ✗ | OA250 | ✗ | ✓ | OC16T | ✗ | ✓ | OC71 | ✓ | ✓ | OC200 | ✓ | ✓ | ||||
2-OC35 | ✗ | ✓ | OA251 | ✗ | ✓ | OC19 | ✗ | ✓ | OC71A | ✓ | ✗ | OC201 | ✓ | ✓ | ||||
2-OC36 | ✗ | ✓ | OA252 | ✗ | ✓ | OC20 | ✗ | ✓ | OC72 | ✓ | ✓ | OC202 | ✗ | ✓ | ||||
2-OC72 | ✓ | ✓ | OAP12 | ✓ | ✓ | OC22 | ✓ | ✓ | OC73 | ✗ | ✓ | OC203 | ✗ | ✓ | ||||
2-OC74 | ✓ | ✗ | OAZ200 | ✓ | ✓ | OC23 | ✓ | ✓ | OC74 | ✓ | ✗ | OC204 | ✗ | ✓ | ||||
LDR03 | ✓ | ✗ | OAZ201 | ✓ | ✓ | OC24 | ✓ | ✓ | OC75 | ✓ | ✓ | OC205 | ✗ | ✓ | ||||
LDR04 | ✓ | ✗ | OAZ202 | ✓ | ✓ | OC25 | ✗ | ✓ | OC75A | ✓ | ✗ | OC206 | ✗ | ✓ | ||||
OA5 | ✓ | ✓ | OAZ203 | ✓ | ✓ | OC26 | ✓ | ✓ | OC76 | ✓ | ✓ | OC207 | ✗ | ✓ | ||||
OA6 | ✗ | ✓ | OAZ204 | ✓ | ✓ | OC28 | ✓ | ✓ | OC77 | ✓ | ✓ | OCP70 | ✓ | ✗ | ||||
OA7 | ✓ | ✓ | OAZ205 | ✓ | ✓ | OC29 | ✓ | ✓ | OC78 | ✗ | ✓ | OCP71 | ✗ | ✓ | ||||
OA9 | ✓ | ✗ | OAZ206 | ✓ | ✓ | OC30 | ✓ | ✓ | OC78D | ✗ | ✓ | ORP10 | ✓ | ✓ | ||||
OA10 | ✗ | ✓ | OAZ207 | ✓ | ✓ | OC30A | ✓ | ✗ | OC79 | ✓ | ✗ | ORP11 | ✓ | ✓ | ||||
OA31 | ✓ | ✓ | OAZ208 | ✓ | ✓ | OC30B | ✓ | ✗ | OC80 | ✓ | ✓ | ORP12 | ✗ | ✓ | ||||
OA47 | ✓ | ✓ | OAZ209 | ✓ | ✓ | OC35 | ✓ | ✓ | OC80A | ✓ | ✗ | ORP13 | ✓ | ✗ | ||||
OA70 | ✓ | ✓ | OAZ210 | ✓ | ✓ | OC36 | ✓ | ✓ | OC81 | ✗ | ✓ | ORP14 | ✓ | ✗ | ||||
OA71 | ✗ | ✓ | OAZ211 | ✓ | ✓ | OC41 | ✗ | ✓ | OC81D | ✗ | ✓ | ORP30 | ✓ | ✗ | ||||
OA72 | ✓ | ✗ | OAZ212 | ✓ | ✓ | OC42 | ✗ | ✓ | OC81DM | ✗ | ✓ | ORP50 | ✓ | ✗ | ||||
OA73 | ✓ | ✓ | OAZ213 | ✓ | ✓ | OC43 | ✗ | ✓ | OC81M | ✗ | ✓ | ORP60 | ✓ | ✓ | ||||
OA79 | ✓ | ✓ | OAZ240 | ✗ | ✓ | OC44 | ✓ | ✓ | OC82 | ✗ | ✓ | ORP61 | ✓ | ✓ | ||||
OA81 | ✓ | ✓ | OAZ241 | ✗ | ✓ | OC45 | ✓ | ✓ | OC82D | ✗ | ✓ | ORP62 | ✓ | ✓ | ||||
OA85 | ✓ | ✓ | OAZ242 | ✗ | ✓ | OC46 | ✓ | ✗ | OC82DM | ✗ | ✓ | ORP63 | ✓ | ✗ | ||||
OA86 | ✓ | ✓ | OAZ243 | ✗ | ✓ | OC47 | ✓ | ✗ | OC83 | ✗ | ✓ | ORP69 | ✓ | ✗ | ||||
OA87 | ✓ | ✗ | OAZ244 | ✗ | ✓ | OC50 | ✓ | ✓ | OC84 | ✗ | ✓ | ORP90 | ✓ | ✓ | ||||
OA90 | ✓ | ✓ | OAZ245 | ✗ | ✓ | OC51 | ✓ | ✓ | OC122 | ✓ | ✓ |
There are some interesting differences visible in the above table:
- The table starts with a number of matched pairs (the entries starting with 2-). Some were made by Mullard, some by Valvo, but few by both.
- Only Valvo made OA9, OA72 and OA87. They did not make OA6, OA10, OA71, OA211 or the power diodes OA250 to OA252.
- Valvo did not make the miniature Zeners OAZ240 to OAZ247.
- Mullard added some suffix letters to variants of OC16, I don't think Valvo did.
- Valvo did not issue the early power types OC19, OC20 and OC25.
- Valvo did not issue the OC41, OC42 and OC43 low-power switching transistors but instead manufactured OC46 and OC47.
- Valvo did not make the types OC73, OC78 and OC78D.
- Valvo made the suffixed variants OC30A, OC30B, OC71A, OC75A and OC80A but Mullard did not. OC71A and OC75A are not listed in the Valvo databooks but I have examples.
- Valvo made the types OC74 and OC79 but Mullard did not.
- Valvo did not make OC81 and OC82, plus their suffixed variants.
- Valvo did not make OC83 and OC84.
- Apparently Valvo did not make OC202 to OC207.
- Valvo made the OCP70 phototransistor (see below) and Mullard made the OCP71. I also have unbranded examples of both.
- For completeness I include the LDRnn and ORPnn cadmium-sulphide photoresistors, although these are not true semiconductor devices. Some use a plastic disc encapsulation and some are in the SO-2 glass/plastic capsule, a few use a glass valve/tube envelope. Valvo seem to have made more types than Mullard but oddly Valvo do not seem to have made ORP12, the most common type, perhaps because LDR03 has similar characteristics.
If you know that any of the above is incorrect, (which is quite possible...), please
This table is a similar comparison for the early pro-Electron-named types. I list the germanium ones (starting with 'A') plus the silicon types BCY10 - BCY12 and BCZ10 - BCZ12 which are found in the SO-2 metal-over-glass outline, plus BC13 and BCZ14 which use a rare miniature encapsulation.
Type | Valvo | Mullard | Type | Valvo | Mullard | Type | Valvo | Mullard | Type | Valvo | Mullard | Type | Valvo | Mullard | ||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
AA119 | ✓ | ✓ | AC172 | ✓ | ✗ | AD161 | ✓ | ✓ | AF180 | ✓ | ✓ | ASZ18 | ✓ | ✗ | ||||
AA129 | ✗ | ✓ | AC176 | ✓ | ✓ | AD162 | ✓ | ✓ | AF181 | ✓ | ✓ | ASZ20 | ✗ | ✓ | ||||
AAY11 | ✗ | ✓ | AC176K | ✓ | ✗ | ADY26 | ✓ | ✓ | AF185 | ✓ | ✗ | ASZ21 | ✓ | ✓ | ||||
AAY12 | ✗ | ✓ | AC187 | ✓ | ✓ | ADZ11 | ✓ | ✓ | AF186 | ✗ | ✓ | ASZ23 | ✓ | ✓ | ||||
AAZ12 | ✓ | ✓ | AC187K | ✓ | ✓ | ADZ12 | ✓ | ✓ | AFY19 | ✗ | ✓ | ATZ10 | ✗ | ✓ | ||||
AAZ13 | ✓ | ✓ | AC188 | ✓ | ✓ | AF102 | ✓ | ✓ | AFZ11 | ✗ | ✓ | AU101 | ✗ | ✓ | ||||
AAZ15 | ✓ | ✓ | AC188K | ✓ | ✓ | AF114 | ✓ | ✓ | AFZ12 | ✓ | ✓ | AU103 | ✓ | ✓ | ||||
AAZ17 | ✓ | ✓ | ACY17 | ✗ | ✓ | AF115 | ✓ | ✓ | ASY26 | ✓ | ✓ | AUY10 | ✓ | ✓ | ||||
AAZ18 | ✓ | ✗ | ACY18 | ✗ | ✓ | AF116 | ✓ | ✓ | ASY27 | ✓ | ✓ | BCY10 | ✓ | ✗ | ||||
AC107 | ✓ | ✓ | ACY19 | ✗ | ✓ | AF117 | ✓ | ✓ | ASY28 | ✗ | ✓ | BCY11 | ✓ | ✗ | ||||
AC125 | ✓ | ✗ | ACY20 | ✗ | ✓ | AF118 | ✓ | ✓ | ASY29 | ✗ | ✓ | BCY12 | ✓ | ✗ | ||||
AC126 | ✓ | ✗ | ACY21 | ✗ | ✓ | AF124 | ✓ | ✓ | ASY31 | ✓ | ✗ | BCZ10 | ✓ | ✗ | ||||
AC127 | ✓ | ✓ | ACY22 | ✗ | ✓ | AF125 | ✓ | ✓ | ASY32 | ✓ | ✗ | BCZ11 | ✓ | ✓ | ||||
AC128 | ✓ | ✓ | AD136 | ✓ | ✗ | AF126 | ✓ | ✓ | ASY67 | ✗ | ✓ | BCZ12 | ✓ | ✗ | ||||
AC128K | ✓ | ✗ | AD139 | ✓ | ✗ | AF127 | ✓ | ✓ | ASZ15 | ✓ | ✗ | BCZ13 | ✓ | ✗ | ||||
AC130 | ✓ | ✗ | AD140 | ✗ | ✓ | AF178 | ✓ | ✓ | ASZ16 | ✓ | ✗ | BCZ14 | ✓ | ✗ | ||||
AC132 | ✓ | ✗ | AD149 | ✓ | ✓ | AF179 | ✗ | ✓ | ASZ17 | ✓ | ✗ |
Again there are differences between the two product sets shown in the above table:
- Valvo do not seem to have made the AA129. This is a transistor in the classic SO-2 glass envelope that was made into a diode by soldering together the base and emitter leads. It was used as a voltage stabiliser. I have some, but all are unbranded.
- Valvo do not seem to have made the AAY11 and AAY12 diodes.
- Mullard did not make the AAZ18 gold-bonded diode despite making other AAZ types.
- Mullard did not make a number of AC1nn transistor types, including some with suffix K (although for those that it did make, Mullard used a suffix /01 instead of the suffix K). This denotes a metal block heatsink and was used extensively by Siemens and Telefunken AC1nn types. My 1974 Valvo 'Datenblatter' has diagrams of such a heatsink, but I have never seen a Valvo example (or indeed one branded Mullard).
- Valvo did not make ACY17 to ACY22, relatively late types in the TO-5 outline.
- Mullard did not make the power types AD136 and AD139, while Valvo did not make AD140.
- Oddly, Valvo did not make AF179 whilst making the others in the group AF178 to AF181.
- Mullard did not make AF185 whilst Valvo did not make AF186.
- Valvo did not make the VHF amplifier transistors AFY19 and AFZ11 (but did make AFZ12).
- Valvo did not make ASY28, ASY29 and ASY67 while Mullard did not make ASY31 and ASY32.
- Mullard did not make the high-power switching transistors ASZ15 to ASZ18.
- Valvo did not make the low-power switching transistor ASZ20.
- Valvo did not make ATZ10 or AU101.
- Valvo made the early silicon transistors BCY10 to BCY12, BCZ10 to BCZ12, and BCZ13 and BCZ14 (see below). Oddly, Mullard seem to have only made the BCZ11.
Here are some interesting types in the Valvo range, but not in Mullard's as far as I know:
- According to the superb radiomuseum site Valvo made a germanium diode type OA74, in fact they show an image of one and state that it was made by 'other Philips related manufacturers'. It also turns up elsewhere in Web searches. Nevertheless it is not found in any early Valvo or Mullard databook that I have seen, although it is listed in the 1963 CV Register as a 'prototype or possible substitute' for CV425. If you know where I can get any branded examples (Valvo or Mullard), please
- Here are the Valvo types OC71A and OC75A. These suffixed versions do not appear in the Valvo databooks I have seen, if you know where I can get data for these, please
- Here's an interesting device: it's the germanium phototransistor OCP70. All the examples I have seen are unbranded except these ones. The rightmost one is printed VALVO. It also bears a stylised crown containing the letters BWB and a number, seen on the middle one. This stands for 'Bundesamt fuer Wehrtechnik und Beschaffung' which translates as 'Federal Office of Defense Technology and Procurement'. I have some that are not marked VALVO, instead they just have the BWB mark and a capital V, seen on the leftmost one, which stands for 'Verteidigungsgeraetenormen' or 'Defense equipment standards'. This means that these devices meet German military specifications.
- Valvo made two triplets of early silicon transistors in the classic SO-2 metal-over-glass outline: BCY10 - BCY12 and BCZ10 - BCZ12. (BCZ10 is shown above). Mullard databooks only contain the BCZ11. Most of the examples I have found are unbranded. I would be interested in Valvo-branded examples of all these types except BCZ10. If you know where I can get any, please
- About 1965, Valvo added this BCZ13 oddity. It is a silicon PNP transistor intended as an AF amplifier and I don't believe that Mullard made it. The only other transistors that use this Philips-group subminiature outline are the germanium OC57 to OC59 intended for use in hearing aids. It is not printed VALVO, but the case is very small, and the examples of OC57 to OC59 that I possess are also unbranded.
- Valvo also issued a similar subminiature type BCZ14. If you know where I can get any, please