01-09-2015, 04:26 PM
(01-09-2015, 11:57 AM)Yorkie Wrote: Don't know if it's an urban myth, but I've read somewhere that the 'yellow' print was meant to be gold, and used in the year of their golden jubilee.
Hmmm - if my memory is correct, it was a very long jubilee, then!
Philips was founded as a private company in 1891 but became a public company - NV Philips' Gloeilampenfabrieken (Literally the Philips Incandescent Light Bulb Company Limited) - in 1912, so the golden anniversary of the latter would have been in 1962 ...
It is only recently that the company name has changed although they still sell, if not actually make, light bulbs!
If you've got any valves kicking around that have lost the print or it is indistinct so that you don't know what the type number is, then - provided it is a Philips valve - it is possible to find out from the top row of etched characters. Years ago when I had racks of valves in the workshop I'd take a guess based on mechanical construction - a something CL82, for example - then take an ECL82, PCL82 and UCL82 of the shelf to see which one matched the original.
Fortunately there is another way!
Someone has gone to the bother of tracking down all the info and has published it here: http://frank.pocnet.net/other/Philips/Ph...ListAB.pdf
In the case of the valves in the pictures, the code is I63. the last digit or symbol is a change or batch code, which can be disregarded. Looking up I6 in the tables shows us that they are examples of the ECC83/12AX7 (as if we didn't already know - but at least it proves that the system works!)
