When was this tube made:Philips PCC88 7DJ8 with Codes: DJH delta 1B4 and 2C3?
Thanks
Philips codes are awful.
Delta was Heerlen Plant Holand code, sold with various labels brands Philips owned as Amperex, Miniwatt, Bugle Boy, Valvo, Mullard, La Radiotechnique RTC, Siemens, Adzam etc
DJH seems to be manufacture series.
1B4 seems to be 1951 or 1961, Month B February, Week 4 apparently as Philips date codes change frequently in the original Ducth manuals and Mullard destroyed his own manufacture documentation when they stopped production.
Google for Philips tube date codes.
