While waiting on this to be delivered I have searched out what available information I can find in regards to the ZM1200 Pandicon.
The developing company was Philips/Mullard consortium and it appeared labelled by both and Valvo who were pointed out as also being in the same consortium. Finding data sheets from all 3 has not been a success as I can only find those from Philips dated 1970 on Dieter Wachter's extensive listings, much copied and displayed in other data sheet sites. There is also another data sheet dated 1969 for the Philips version elsewhere that I just found. (edit) The development version seemed to have been produced in quite a large quantity at the time before the introduction of the production version with the differences being the mesh patterns, square in the development one and hexagonal in the production one. Development versions also had the label on the back of the tube stating that it was a development sample and that further supplies were not guaranteed. Information from a collector states that the development versions had serial numbers etched or stamped on the rear plate and on the photos he posted the production version was white ink stamped with 'Philips ZM1200'. The tube I posted initially has 'Mullard, ZM1200, Made in Holland' white inked on the rear, I have seen a Valvo version with the white ink stamping and also a Philips one with a printed label on the rear. Examples of the smaller versions such as the ZM1206, has an 'Amperex, Made in Holland' label (photo) <http://www7a.biglobe.ne.jp/~ebiharasho/other_tube.htm>, while a ZM1202 has Valvo ZM1202 white ink stamped on it as does a ZM1204. The Valvo stampings can be seen here on Udo Radtke's <http://www.tubecollection.de/ura/pandicon.htm> collection. The rarity of the ZM12xx series make it difficult to get accurate information on them and any further info would be much appreciated. Roddy -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/b35c400b-5257-4031-8000-e4351b0577e0%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
