The Hungarian company Tungsram originally had three valve/tube factories in London, one being the 'British Tungsram Radio Works', in West Road, Tottenham. The brief entry in Graces Guide states that 'British Tungsram' was taken over by Philips/Mullard in 1952. Mainly it sold thermionic valves/tubes, which can be readily found on eBay. It also sold a few semiconductors, although I have some questions about this. Perhaps the most obvious is: why did it retain the 'Tungsram' branding? It did so, which implies that semiconductors marked 'TUNGSRAM' may not be Hungarian. Such devices cannot, however, bear the Tungsram logo. British Tungsram changed its name to 'Tottenham Road Valve Co. Ltd.' and its branding to 'TORVAC' in the early 1970s. I don't know if this was done for legal reasons. It was apparently dissolved in the latter half of 1978.

If you can provide more detail about British Tungsram, please


Tungsram AC128 transistor

This AC128 in the standard Pro-Electron TO-1 outline comes in a rather nice aluminium tube that bears the words 'TUNGSRAM SEMICONDUCTORS' plus the Tottenham address, and was therefore made by 'British Tungsram', although the transistor itself is unbranded. It is a germanium PNP AF output type and is probably a Mullard device. It raises the probability that British Tungsram did not manufacture semiconductors, but just re-packaged Mullard types.

Hungarian Tungsram also made AC128, but in their typical tall flanged TO-1 outline, and bearing their logo.


Tungsram AC107 transistor Tungsram OC72 transistor

Here are an OC72 and an AC107 both printed TUNGSRAM. Both look absolutely identical to Mullard/Philips versions, and both look like the TUNGSRAM has been printed separately from the part number AC107. I strongly suspect these to be unbranded Mullard stock rebranded by British Tungsram.


TORVAC OC75 transistor

British Tungsram changed its name to 'Tottenham Road Valve Co. Ltd.' in the early 1970s. It certainly sold some Philips/Mullard transistor types and printed 'TORVAC' on them. My image shows an OC75 printed 'TORVAC' and stored in a 4-inch aluminium tube (longer than that of the AC128 above) that is printed 'A PRODUCT OF TOTTENHAM ROAD VALVE CO. LTD., ENGLAND' but does not bear an address. I would be interested to find more such types, or any TORVAC semiconductor data literature. If you can help, please