Tungsram logo I have very little information about the early manufacture of semiconductors in Hungary. The long-established electrical manufacturer Tungsram, famous for the production of electric lighting, produced germanium transistors in the standard pro Electron series AC, AD, AF and possibly others. They also produced transistors in the Mullard/Philips OC series, and diodes in the OA and AA series. I have no data books or sheets describing any of these.

I do know that Tungsram had a building in London; the "British Tungsram Radio Works", in West Road, Tottenham. However I do not know if they manufactured semiconductors there.

If you can provide more detail about Tungsram, please

AC125 transistor Here is a Tungsram AC125 in the TO-1A package. This common type is a PNP germanium alloy transistor for AF pre-amplifier applications, equivalent to the Mullard OC70 or OC71.

AC128 transistor Here is a Tungsram AC128 in the standard TO-1 package, but sold in a rather nice metallic tube that bears the words "TUNGSRAM SEMICONDUCTORS" plus the London address.

AD161 transistor Here is a Tungsram AD161: an early AF 4-watt amplifier transistor in the TO-66 package, often paired with the complementary AD162. The majority of these transistors were made by Philips/Mullard and Siemens and they can be readily found today. Tungsram examples are rarer.

OC1077 transistor OC1079 transistor Tungsram made germanium transistors in the Mullard OC series, but for many of them they added 1000 to the part number:

  • The OC1079 on the right is equivalent to an OC79 and uses a package similar to the Philips SO-2 original.
  • The OC1077 on the left is equivalent to an OC77, but uses the smaller TO-1A can with a clip-on heatsink.

They also did this for ASZnn and possibly other pro-Electron series types.

If you know anything about this numbering, please

P13AT transistor I have an old Hungarian transistor list from 1960 and it mentions two unusual Tungsram types: the P14 and P15 are apparently low-power PNP germanium RF transistors. Unfortunately their encapsulation is not shown. I have not found them, but I have obtained some P13AT transistors as shown, however I have no data for them.

If you know anything about this P series, please

I have little more to show in the way of Hungarian semiconductors. Please help fill this gap if you can!

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