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Decoding Date Codes

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  • joshbensadon
    ... Here s a transistor with 430 on it. Would that make it 1964, week 30? Transistor part number is 2N1218. Or does the 430 refer to the factory the
    Message 1 of 31 , Oct 18, 2012
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      --- In midatlanticretro@yahoogroups.com, "s100doctor" <hjohnson@...> wrote:
      >
      >
      > 1) Date codes on many components are in the format YYWW where YY is the year ([19]72, 73, 74....), YY is the week of the year (01-52).

      Here's a transistor with 430 on it. Would that make it 1964, week 30?
      Transistor part number is 2N1218. Or does the 430 refer to the factory the transistor was made? or other?

      Photo of transistor posted in the photos/Josh Bensadon folder of this group.

      I've seen some IC's with only a 3 digit code on them (not part of this analog computer). Case in point is the following:

      CD4023BE
      RCA H 650

      Is that to mean 1976 week 50?
      H being the factory where it was made?

      Cheers,
      Josh
    • Bill Dromgoole
      ... Yes, In my opinion you are correct. In the early years of semiconductors most parts have three digit date codes. You have to know the approximate decade
      Message 31 of 31 , Oct 18, 2012
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        >
        > Here's a transistor with 430 on it. Would that make it 1964, week 30?
        > Transistor part number is 2N1218. Or does the 430 refer to the factory the
        > transistor was made? or other?
        >
        > Photo of transistor posted in the photos/Josh Bensadon folder of this group.
        >
        > I've seen some IC's with only a 3 digit code on them (not part of this analog
        > computer). Case in point is the following:
        >
        > CD4023BE
        > RCA H 650
        >
        > Is that to mean 1976 week 50?
        > H being the factory where it was made?
        >
        > Cheers,
        > Josh
        > ------------------------------------

        Yes, In my opinion you are correct.
        In the early years of semiconductors most parts have three digit date codes.
        You have to know the approximate decade the part was first produced to get the
        correct date.

        Sometimes you have trouble telling the part number apart from the date code.
        In the 1970s a lot of the 7400 series ic's had date codes like 7414 and a part
        number like 7404.
        I was always having trouble with those.

        A good history of early transitor marking can be found here.
        http://transistorhistory.50webs.com/index.html

        billdrom
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