Any Danes around? Bought a batch of tubes and this one had all prints scrubbed off. However, there was a code on the underside of the tube which revealed it was an ECC81 made by Philips in Copenhagen, Denmark. Horse-shoe getter and ribbed short plates. Strangely enough no date codes (may have been printed on the glass), only a "+" sign after the Copenhagen pyramid symbol. Can anyone shed a light on this?
Danish tube collectors seem to be scarce in this forum, but I got help from Gibosi who's active on Head-Fi.
This ECC81 uses the old Philips code, described in this ever so useful document:
https://frank.pocnet.net/other/Philips/PhilipsCodeListAB.pdf
According to this code list the "X" is the month of December for the years 1950, 1953, 1956. the "B" is the change code for the years 1951-1953. Which means that this Danish ECC81 (=Tk) was manufactured in December 1953. As all told to me by Gibosi- thanks! I've had some new insights with this information so I pass it along to all you avid tube fans out there.
This ECC81 uses the old Philips code, described in this ever so useful document:
https://frank.pocnet.net/other/Philips/PhilipsCodeListAB.pdf
According to this code list the "X" is the month of December for the years 1950, 1953, 1956. the "B" is the change code for the years 1951-1953. Which means that this Danish ECC81 (=Tk) was manufactured in December 1953. As all told to me by Gibosi- thanks! I've had some new insights with this information so I pass it along to all you avid tube fans out there.
That's so much easier to read than the typically faint etch on the lower side. I've got what I think is a Blackburn 12ax7, but the ink printing is over the etched code. If I could definitively prove there's a "B" there, it would make it more valuable.