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#1
Posted to rec.audio.tubes
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GEC KT88 Date manufactured and where?
Found two GEC KT88 tubes in the attic, (not boxed).
In the rectangle, below the designation "KT88" is, I think, a date and manufacture code of: "RB Z" Anyone know when these were manufactured? They are similar looking to: http://www.natubes.com/data/images/p.../large_517.gif |
#2
Posted to rec.audio.tubes
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GEC KT88 Date manufactured and where?
On Aug 31, 7:52*pm, Richard wrote:
Found two GEC KT88 tubes in the attic, (not boxed). In the rectangle, below the designation "KT88" is, I think, a date and manufacture code of: "RB *Z" Anyone know when these were manufactured? They are similar looking to: http://www.natubes.com/data/images/p.../large_517.gif Don't take this as gospel. I am assuming that what you are referring to is the CV number. RB = Ferranti, Dundee Z might be a test specification. http://www.tubecollector.org/cv-valves.htm |
#3
Posted to rec.audio.tubes
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GEC KT88 Date manufactured and where?
kheper schrieb:
On Aug 31, 7:52 pm, Richard wrote: Found two GEC KT88 tubes in the attic, (not boxed). In the rectangle, below the designation "KT88" is, I think, a date and manufacture code of: "RB Z" Anyone know when these were manufactured? They are similar looking to: http://www.natubes.com/data/images/p.../large_517.gif Don't take this as gospel. I am assuming that what you are referring to is the CV number. RB = Ferranti, Dundee Z might be a test specification. http://www.tubecollector.org/cv-valves.htm according to this page - thanks for the link - it might also mean MO Valve Company, Hammersmith which would be very likely for a KT88. RB might be the date code according to this source: "Alternatively two letters were used. This was allowed up to January 1st 1965. In this scheme the first letter A = 1945 and so on, and the second letter A=January and so on. Letters I and O were not used. Thus AA = January 1945, NF = June 1957." Feb 1960? regards Jochen |
#4
Posted to rec.audio.tubes
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GEC KT88 Date manufactured and where?
On 01/09/2010 06:41, jh wrote:
kheper schrieb: On Aug 31, 7:52 pm, Richard wrote: Found two GEC KT88 tubes in the attic, (not boxed). In the rectangle, below the designation "KT88" is, I think, a date and manufacture code of: "RB Z" Anyone know when these were manufactured? They are similar looking to: http://www.natubes.com/data/images/p.../large_517.gif Don't take this as gospel. I am assuming that what you are referring to is the CV number. RB = Ferranti, Dundee Z might be a test specification. http://www.tubecollector.org/cv-valves.htm according to this page - thanks for the link - it might also mean MO Valve Company, Hammersmith which would be very likely for a KT88. RB might be the date code according to this source: "Alternatively two letters were used. This was allowed up to January 1st 1965. In this scheme the first letter A = 1945 and so on, and the second letter A=January and so on. Letters I and O were not used. Thus AA = January 1945, NF = June 1957." Feb 1960? regards Jochen Thanks. I think that is probably correct. Made at Hammersmith February 1960. Interesting discussion here on date codes: http://forum.marstran.com/viewtopic.php?f=6&t=130 |
#5
Posted to rec.audio.tubes
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GEC KT88 Date manufactured and where?
On Sep 1, 7:31*am, Richard wrote:
On 01/09/2010 06:41, jh wrote: kheper schrieb: On Aug 31, 7:52 pm, Richard wrote: Found two GEC KT88 tubes in the attic, (not boxed). In the rectangle, below the designation "KT88" is, I think, a date and manufacture code of: "RB Z" Anyone know when these were manufactured? They are similar looking to: http://www.natubes.com/data/images/p.../large_517.gif Don't take this as gospel. I am assuming that what you are referring to is the CV number. RB = Ferranti, Dundee Z might be a test specification. http://www.tubecollector.org/cv-valves.htm according to this page - thanks for the link - it might also mean MO Valve Company, Hammersmith which would be very likely for a KT88. RB might be the date code according to this source: "Alternatively two letters were used. This was allowed up to January 1st 1965. In this scheme the first letter A = 1945 and so on, and the second letter A=January and so on. Letters I and O were not used. Thus AA = January 1945, NF = June 1957." Feb 1960? regards Jochen Thanks. I think that is probably correct. Made at Hammersmith February 1960. Interesting discussion here on date codes: http://forum.marstran.com/viewtopic.php?f=6&t=130 Yeah, my error. I do not see how I missed that paragraph. Anyway, nice KT88 tubes. |
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