Sobre las Telefunken ECC82 y los códigos de las válvulas

hola, hablando con un vendedor francés de ebay, bastante simpático el hombre, sobre unas Telefunken que me ofrecía pero con el sello de Mazda me decía esto:

"Philips owned most of the factories since the early 60's, (Mullard, Siemens, Mazda, EI, Philips, RFT, Telefunken, RTC, Matsushita, Valvo, Ferranti, etc.) so when a factory as Mazda, or Mullard or Siemens for instance, needed supplies, the others factories sent them tubes on which the other factory put its label on. So you have Siemens label tubes which were made by EI, RTC label tubes which were made by Mullard for instance. So when you buy a tube, don't look only its label, ask for the acid engraved code on the tube which is the only thing which makes you know who made it. It will avoid you to pay the high price for Mullard label tubes made by Philips for instance. The Telefunken ECC82 I sell are genuine Telefunken with diamond between pins but with a different label. They were made in Berlin as the Telefunken branded tubes.

For instance:

http://www.ebay.fr/itm/12AU7-ECC82-EI-Vacuum-Tube-Valve-Rohren-emission-mutual-conductance-/142282244871?ssPageName=STRK:MESE:IT

This is a EI made ECC82 but with a Siemens label. I could sell it for more if I would say it s a siemens made tube, but I wouldn't be honest."

y en base a esto me mandaba este enlace con el pdf donde explica los códigos a los que se refiere.

https://frank.pocnet.net/other/Philips/PhilipsCodeListAB.pdf


lo dejo por aquí a modo informativo, no sé qué "credibilidad" tiene lo que me cuenta ni conocimientos para validarla o rebatirla, así que cada cual que haga el caso que le parezca a la información.

o si podéis aportar algo, creo que el tema es interesante a la hora de saber qué compramos en estos temas con tantas historias y leyendas urbanas.

salud!