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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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8th Jul 2021, 3:14 pm | #1 |
Heptode
Join Date: Jun 2005
Location: Sunderland, Tyne and Wear, UK.
Posts: 661
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Mullard UF 41 Date Code How To Identify Year?
Hi i am trying to identify the year where this Mullard UF 41 was made there are no etched codings on the side but painted next to the valve pins in white are Nm7 BA5 is this the date code and how do read the code ? kind regards Bob
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8th Jul 2021, 7:41 pm | #2 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
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Re: Mullard UF 41 Date Code How To Identify Year
https://mullard.org/blogs/news/mulla...interpret-them
BA5 looks like Blackburn, January 1955. |
8th Jul 2021, 7:47 pm | #3 |
Octode
Join Date: Dec 2018
Location: Llandeilo, West Wales, UK.
Posts: 1,092
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Re: Mullard UF 41 Date Code How To Identify Year
Everything you need to know here:
https://frank.pocnet.net/other/Phili...CodeListAB.pdf
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9th Jul 2021, 11:16 am | #4 |
Dekatron
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,185
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Re: Mullard UF 41 Date Code How To Identify Year
Strange code. Doesn't confirm to the 1948-1956 standard as the second line has 3 positions, nor to the later standard as the A and the 5 seem swapped.
Possibly Mullard got rid of the old coding system before Eindhoven had set a firm standard for the new one. In that case I would tend to agree on january 1955. What construction does it use? Is the tube fritted (looks like transparent glue but is actually a layer of low melting glass) to the bottom and does the bottom plate have green 'beads' around the pins (which are stiff, not bendy)? Given the factory stamping is on the bottom and not on the side, I suppose the bottom is fritted? |
9th Jul 2021, 7:23 pm | #5 |
Heptode
Join Date: Jun 2005
Location: Sunderland, Tyne and Wear, UK.
Posts: 661
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Re: Mullard UF 41 Date Code How To Identify Year
Hi thanks for replies to everyone i would say it is January 1955 and it does have green beads around the pins and it has no factory stamping on the side and it is on the bottom kind regards Bob
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