Valvo OC170/1 tin whiskers?

[paulsherwin]

I'm currently scrapping a a Graetz Joker 834 which was an unsalvageable shed find. Does anyone know if Valvo transistors of the late 50s / early 60s suffer from the same tin whisker problems as the UK Mullard versions? I'm obviously mostly interested in the RF/IF parts to use as AF11x replacements, but I think there are a couple of OC71s and OC74s in there too.

https://www.radiomuseum.org/r/graetz_joker_834.html

[paulsherwin]

Some sources claim that Valvo never actually made OC170/1s and just put their branding on Mullard production. Can anybody confirm this?

[G6Tanuki]

Originally Posted by paulsherwin

Some sources claim that Valvo never actually made OC170/1s and just put their branding on Mullard production. Can anybody confirm this?

Can't confirm it, but would be totally prepared to believe it - just as valve manufacturers often 'outsourced' production between themselves, specially if there were production/demand mismatches.

[I have seen Mullard-branded OC44/45/71 transistors - in an envelope whose top was rather squarer than the usual Mullard rounded-point style - marked 'Made in France']

[Paul Stenning]

Originally Posted by G6Tanuki

[I have seen Mullard-branded OC44/45/71 transistors - in an envelope whose top was rather squarer than the usual Mullard rounded-point style - marked 'Made in France']

Mullard made smaller OC44M and OC45M versions, although they are not common. See attached data.

[G6Tanuki]

The French Mullard OC-series ones I recall were not 'miniature' in any way - they were the same length as classic Mullard OC44/45/71 but just with a flat top rather than the domed top.

[I'm familiar with 'miniature' OC-numbered audio transistors in the OC50.51.52 series, and similarly-small ones used in the likes of the Fi-Cord handheld dictation-machines of the late-50s/early-60s]

[Restoration73]

Philips had an affiliate factory in France making transistors, la Radiotechnique. I have
a range of germanium devices which look like Philips (i.e. Holland) devices.

[paulsherwin]

Philips had 4 semiconductor manufacturers in the 50s and 60s - Philips themselves in Eindhoven, Mullard in Britain, Valvo in West Germany and Radiotechnique in France. They all seem to have supplied each other with parts, but were also allowed to develop their own devices using their local manufacturing facilities. Some of this odd behaviour may have been to circumvent local content tarrifs in effect at the time. Transistors were by far the highest cost components then.

[pmmunro]

Latterly, there was at least a fifth semiconductor plant within the Philips group, Newmarket Transistors. They were one of three Group enterprises on the Exning Road in Newmarket, the others being Varelco (connectors) and Magnetic Devices (affectionately, and derisively referred to as Magic Gadgets).

Newmarket Transistors certainly made their own devices under Philips ownership but I don't know if they supplied these internally within the Group.

PMM

[Maarten]

Originally Posted by paulsherwin

Some sources claim that Valvo never actually made OC170/1s and just put their branding on Mullard production. Can anybody confirm this?

Without particular inside knowledge I'd say this is unlikely. Unfortunately I don't know how to decode the production codes on older transistors so I don't have a way to tell for sure.

I assume those transistors initially were a Dutch development. If they were really developed in the UK, production elsewhere is still likely, though.

Production for Dutch developed semiconductors usually started in The Netherlands and was expanded to other factories (Germany, UK, France, etc.) based on demand. I'm pretty sure Matsushita made them under license instead of importing them, so that would likely place production in Japan as well.