Re: Who made this National 6922?

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In Reply to: Who made this National 6922? posted by analogue_man on August 10, 2005 at 05:22:16:

Best guess relabeled 6DJ8 made by Matsushita with Mullard tooling.
It can only be Amperex or Siemens if you see an etched code on glass with a delta (for Amperex, and sometimes can be VERY hard to see) or a shiny metal plate attached to the getter support with stamped numbers for the Siemens. Also look at the base between pins - do you see a distinct number? No - no Siemens, period.
Other internal structures besides getter and shield can be very telling, that's why a picture is good. For example, the horizontal plates can be serrated for Siemens or smooth for Heerlen type tubes.
Regarding this tube killing the BB, no doubt different apps and different ears lead to different results, but I'll guess that you used BB with small, round getter and didn't try Mullards OR BB with large O getter OR D-getter BB.

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Topic - Who made this National 6922? - analogue_man 05:22:16 08/10/05 (6)

Re: Who made this National 6922? - romandoc 07:06:38 08/10/05 (0)

Re: Who made this National 6922? - Jimmy 06:50:36 08/10/05 (4)

Here is the picture of the tube - analogue_man 15:03:04 08/10/05 (3)

Yep, Matsushita 6DJ8, no doubt - romandoc 19:00:46 08/10/05 (2)

Re: Yep, Matsushita 6DJ8, no doubt - analogue_man 02:25:39 08/11/05 (1)

Re: Yep, Matsushita 6DJ8, no doubt - romandoc 09:11:30 08/11/05 (0)

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Re: Who made this National 6922? - romandoc 07:06:38 08/10/05 (0)

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