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  • ua208a

    From bitrex@21:1/5 to All on Thu Aug 25 11:26:17 2022
    Is there a suitable modern replacement for the ua208a TO-99 can-type
    op amp as used in e.g. the HP oven oscillators, that's available and
    doesn't cost an arm and a leg?

    <https://datasheetspdf.com/pdf/1305470/Fairchild/UA208A/1>

    Probably less expensive to just buy another module, maybe

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  • From Peter W.@21:1/5 to All on Thu Aug 25 09:52:56 2022
    Have you tried Fairchild directly? They may have attic stock somewhere.

    https://www.semiconductor-technology.com/contractors/component/fairchildco/

    Peter Wieck
    Melrose Park, PA

    --- SoupGate-Win32 v1.05
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  • From bitrex@21:1/5 to Peter W. on Thu Aug 25 13:19:06 2022
    On 8/25/2022 12:52 PM, Peter W. wrote:
    Have you tried Fairchild directly? They may have attic stock somewhere.

    https://www.semiconductor-technology.com/contractors/component/fairchildco/

    Peter Wieck
    Melrose Park, PA


    I haven't. Rochester has some possibly appropriate subs but there's
    relatively large minimum quantities:

    <https://www.digikey.com/en/products/detail/rochester-electronics-llc/PM1008AJ/12120663>

    I'd tend to guess anyone with "attic stock" doesn't want to deal in
    onsies and twosies, either.

    This site lets you add onsies and twosies to the cart of Rochester items
    but seems a bit sus:

    <https://www.sinlinelec.com/>

    And there's always fleabay mystery meat:

    <https://tinyurl.com/ms38bfxd>

    Finding a sub among other things means it's specced to the mil
    temperature range, -55 to 125 C. A cool thing about the CA3140 is most
    variants in DIP have that spec which I believe is a little unusual, unfortunately since it's a FET input even the boutique grade of it has
    offset voltage too high.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Peter W.@21:1/5 to All on Thu Aug 25 10:26:57 2022
    I'd tend to guess anyone with "attic stock" doesn't want to deal in
    onsies and twosies, either.

    My experience has been exactly the opposite. Worth a shot in any case.

    Peter Wieck
    Melrose Park, PA

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From bitrex@21:1/5 to Peter W. on Thu Aug 25 14:04:06 2022
    On 8/25/2022 1:26 PM, Peter W. wrote:
    I'd tend to guess anyone with "attic stock" doesn't want to deal in
    onsies and twosies, either.

    My experience has been exactly the opposite. Worth a shot in any case.

    Peter Wieck
    Melrose Park, PA

    Oh nice, OK good to know thank you

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From jf0303222@gmail.com@21:1/5 to bitrex on Thu Aug 25 16:03:00 2022
    On Thursday, August 25, 2022 at 8:26:24 AM UTC-7, bitrex wrote:
    Is there a suitable modern replacement for the ua208a TO-99 can-type
    op amp as used in e.g. the HP oven oscillators, that's available and
    doesn't cost an arm and a leg?

    <https://datasheetspdf.com/pdf/1305470/Fairchild/UA208A/1>

    Probably less expensive to just buy another module, maybe
    I think this is just the Fairchild equivalent of the National LM108/2008/308 series, with the LM108 being the high-spec version and the LM208 and LM308 being cheaper versions. The LM part numbers are readily available on the bay and probably from your
    favorite surplus electronics dealer (especially if the LM308 is good enough for you).

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From bitrex@21:1/5 to jfeng@my-deja.com on Thu Aug 25 19:22:12 2022
    On 8/25/2022 7:03 PM, jfeng@my-deja.com wrote:
    On Thursday, August 25, 2022 at 8:26:24 AM UTC-7, bitrex wrote:
    Is there a suitable modern replacement for the ua208a TO-99 can-type
    op amp as used in e.g. the HP oven oscillators, that's available and
    doesn't cost an arm and a leg?

    <https://datasheetspdf.com/pdf/1305470/Fairchild/UA208A/1>

    Probably less expensive to just buy another module, maybe
    I think this is just the Fairchild equivalent of the National LM108/2008/308 series, with the LM108 being the high-spec version and the LM208 and LM308 being cheaper versions. The LM part numbers are readily available on the bay and probably from your
    favorite surplus electronics dealer (especially if the LM308 is good enough for you).

    It's pretty close, though the 208 has tighter V offset max, 0.5 mV vs 2.

    Under the circumstances (of it not being the year 1980, say) the 108
    might be the best compromise

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From bitrex@21:1/5 to Dave Platt on Thu Aug 25 20:48:00 2022
    On 8/25/2022 8:24 PM, Dave Platt wrote:
    In article <e4791536-d5a1-4b2c-9000-784b9d759277n@googlegroups.com>, jfeng@my-deja.com <jf0303222@gmail.com> wrote:
    On Thursday, August 25, 2022 at 8:26:24 AM UTC-7, bitrex wrote:
    Is there a suitable modern replacement for the ua208a TO-99 can-type
    op amp as used in e.g. the HP oven oscillators, that's available and
    doesn't cost an arm and a leg?

    <https://datasheetspdf.com/pdf/1305470/Fairchild/UA208A/1>

    Probably less expensive to just buy another module, maybe
    I think this is just the Fairchild equivalent of the National LM108/2008/308 series, with the LM108 being the
    high-spec version and the LM208 and LM308 being cheaper versions. The LM part numbers are readily available on
    the bay and probably from your favorite surplus electronics dealer (especially if the LM308 is good enough for
    you).

    There are also plenty of more modern high-spec single op amps in small
    SOIC-8 and DIP-8 packages. Brown Dog makes an adapter (020601A) which accepts a DIP-8 IC, and converts to a TO-99 circular pinout pattern;
    you can buy it either with or without pins installed for the TO-99, and with or without a socket.

    That'd be a helpful tool

    The ua208a has provisions for a compensation capacitor; you might find
    that modern unity-gain-stable op amps are fast enough and stable
    enough that you could simply ignore this (leave the TO-99 pins
    unconnected).
    OPA228PA is a nice precision OA with the mil spec temperature range:

    <https://www.mouser.com/ProductDetail/Texas-Instruments/OPA228PA?qs=7nS3%252BbEUL6ulkTCjUT78yA%3D%3D>

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Dave Platt@21:1/5 to jfeng@my-deja.com on Thu Aug 25 17:24:59 2022
    In article <e4791536-d5a1-4b2c-9000-784b9d759277n@googlegroups.com>, jfeng@my-deja.com <jf0303222@gmail.com> wrote:
    On Thursday, August 25, 2022 at 8:26:24 AM UTC-7, bitrex wrote:
    Is there a suitable modern replacement for the ua208a TO-99 can-type
    op amp as used in e.g. the HP oven oscillators, that's available and
    doesn't cost an arm and a leg?

    <https://datasheetspdf.com/pdf/1305470/Fairchild/UA208A/1>

    Probably less expensive to just buy another module, maybe
    I think this is just the Fairchild equivalent of the National LM108/2008/308 series, with the LM108 being the
    high-spec version and the LM208 and LM308 being cheaper versions. The LM part numbers are readily available on
    the bay and probably from your favorite surplus electronics dealer (especially if the LM308 is good enough for
    you).

    There are also plenty of more modern high-spec single op amps in small
    SOIC-8 and DIP-8 packages. Brown Dog makes an adapter (020601A) which
    accepts a DIP-8 IC, and converts to a TO-99 circular pinout pattern;
    you can buy it either with or without pins installed for the TO-99, and with
    or without a socket.

    The ua208a has provisions for a compensation capacitor; you might find
    that modern unity-gain-stable op amps are fast enough and stable
    enough that you could simply ignore this (leave the TO-99 pins
    unconnected).

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)