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Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

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  • /M
    Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin. Magnus
    Message 1 of 21 , Jul 10, 2013
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      Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin.
       
      Magnus
    • Dana Myers
      ... The original poster corrected himself - it s a CA3401, which was the RCA second-source for the LM3900. It s a quad Norton amp. Also, sound card input on
      Message 2 of 21 , Jul 10, 2013
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        On 7/10/2013 1:04 PM, /M wrote:
         

        Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin.
         


        The original poster corrected himself - it's a CA3401, which was the RCA second-source for
        the LM3900. It's a quad Norton amp.

        Also, sound card input on most PCs both a mic level and line-level input, the original
        poster would notice pretty quickly if over-driving the mic input :-)

        Cheers -
        Dana  K6JQ

      • joshbensadon
        ... Wow, I never heard of a resistor failing in a short condition. I m guessing that must be a very rare occurrence. I once found a diode marked backwards! It
        Message 3 of 21 , Jul 10, 2013
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          > I've mostly only seen resistors fail when they are operated over their rated power dissipation, or under it but over temperature. They usually fail open.
          >
          > I was astounded to find a resistor in a PDP-11/05 front panel that failed shorted, so apparently that can happen also, but I think it's very unlikely.



          Wow, I never heard of a resistor failing in a short condition.
          I'm guessing that must be a very rare occurrence.

          I once found a diode marked backwards! It was a 1N914 diode. I found it in a new circuit board off the assembly line that wasn't working. I kept it for a long time on my bench and showed a few people, then decided to throw it away.

          My mistake for not buying a lottery ticket that day.

          :)J
        • /M
          Ooops! Missed that. I happen to have the Applican Note ICAN-6934 Cassete Tape I/O For COSMAC Microprocessor Systems . Maybe I should run the leaflet in the
          Message 4 of 21 , Jul 10, 2013
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            Ooops! Missed that.
             
            I happen to have the Applican Note ICAN-6934 'Cassete Tape I/O For COSMAC Microprocessor Systems'.
            Maybe I should run the leaflet in the scanner and share it?!
             
            Magnus
             
             
            ----- Original Message -----
            Sent: Wednesday, July 10, 2013 10:17 PM
            Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

             

            On 7/10/2013 1:04 PM, /M wrote:
             

            Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin.
             


            The original poster corrected himself - it's a CA3401, which was the RCA second-source for
            the LM3900. It's a quad Norton amp.

            Also, sound card input on most PCs both a mic level and line-level input, the original
            poster would notice pretty quickly if over-driving the mic input :-)

            Cheers -
            Dana  K6JQ

          • Jorgen Nordqvist
            Would love a copy of that application note, if you have the time. _____ From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf Of /M
            Message 5 of 21 , Jul 11, 2013
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              Would love a copy of that application note, if you have the time.
               

              From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf Of /M
              Sent: Thursday, 11 July 2013 6:31 AM
              To: cosmacelf@yahoogroups.com
              Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

               

              Ooops! Missed that.
               
              I happen to have the Applican Note ICAN-6934 'Cassete Tape I/O For COSMAC Microprocessor Systems'.
              Maybe I should run the leaflet in the scanner and share it?!
               
              Magnus
               
               
              ----- Original Message -----
              Sent: Wednesday, July 10, 2013 10:17 PM
              Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

               

              On 7/10/2013 1:04 PM, /M wrote:
               

              Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin.
               


              The original poster corrected himself - it's a CA3401, which was the RCA second-source for
              the LM3900. It's a quad Norton amp.

              Also, sound card input on most PCs both a mic level and line-level input, the original
              poster would notice pretty quickly if over-driving the mic input :-)

              Cheers -
              Dana  K6JQ

              No virus found in this message.
              Checked by AVG - www.avg.com
              Version: 2013.0.3349 / Virus Database: 3204/6478 - Release Date: 07/09/13

            • /M
              Later this evening. Magnus ... From: Jorgen Nordqvist To: cosmacelf@yahoogroups.com Sent: Thursday, July 11, 2013 12:49 PM Subject: RE: [cosmacelf] Re: LM3900
              Message 6 of 21 , Jul 11, 2013
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                Later this evening.
                 
                Magnus
                 
                 
                ----- Original Message -----
                Sent: Thursday, July 11, 2013 12:49 PM
                Subject: RE: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                 

                Would love a copy of that application note, if you have the time.
                 

                From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf Of /M
                Sent: Thursday, 11 July 2013 6:31 AM
                To: cosmacelf@yahoogroups.com
                Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                 

                Ooops! Missed that.
                 
                I happen to have the Applican Note ICAN-6934 'Cassete Tape I/O For COSMAC Microprocessor Systems'.
                Maybe I should run the leaflet in the scanner and share it?!
                 
                Magnus
                 
                 
                ----- Original Message -----
                Sent: Wednesday, July 10, 2013 10:17 PM
                Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                 

                On 7/10/2013 1:04 PM, /M wrote:
                 

                Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin.
                 


                The original poster corrected himself - it's a CA3401, which was the RCA second-source for
                the LM3900. It's a quad Norton amp.

                Also, sound card input on most PCs both a mic level and line-level input, the original
                poster would notice pretty quickly if over-driving the mic input :-)

                Cheers -
                Dana  K6JQ

                No virus found in this message.
                Checked by AVG - www.avg.com
                Version: 2013.0.3349 / Virus Database: 3204/6478 - Release Date: 07/09/13

              • ekeefe8051
                Hello, A copy of the ICAN-6934 Application note is in the files section of this group in the VIP section. It is the first link. I hope this helps. ED
                Message 7 of 21 , Jul 11, 2013
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                  Hello,

                  A copy of the ICAN-6934 Application note is in the files section of this group in the "VIP" section. It is the first link.

                  I hope this helps.

                  ED

                  --- In cosmacelf@yahoogroups.com, "Jorgen Nordqvist" <jnord@...> wrote:
                  >
                  > Would love a copy of that application note, if you have the time.
                  >
                  > _____
                  >
                  > From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf
                  > Of /M
                  > Sent: Thursday, 11 July 2013 6:31 AM
                  > To: cosmacelf@yahoogroups.com
                  > Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?
                  >
                  >
                  >
                  >
                  >
                  > Ooops! Missed that.
                  >
                  > I happen to have the Applican Note ICAN-6934 'Cassete Tape I/O For COSMAC
                  > Microprocessor Systems'.
                  > Maybe I should run the leaflet in the scanner and share it?!
                  >
                  > Magnus
                  >
                  >
                  >
                  > ----- Original Message -----
                  > From: Dana Myers <mailto:dana.myers@...>
                  > To: cosmacelf@yahoogroups.com
                  > Cc: /M <mailto:tubes@...> ; spacewar@...
                  > Sent: Wednesday, July 10, 2013 10:17 PM
                  > Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?
                  >
                  >
                  >
                  >
                  >
                  > On 7/10/2013 1:04 PM, /M wrote:
                  >
                  >
                  >
                  >
                  >
                  >
                  > Maybe there has already been this info, but as I recall, the CA3140 was a
                  > FET or even a MOSFET OPamp with almost infinite Zin.
                  >
                  >
                  >
                  >
                  > The original poster corrected himself - it's a CA3401, which was the RCA
                  > second-source for
                  > the LM3900. It's a quad Norton amp.
                  >
                  > Also, sound card input on most PCs both a mic level and line-level input,
                  > the original
                  > poster would notice pretty quickly if over-driving the mic input :-)
                  >
                  > Cheers -
                  > Dana K6JQ
                  >
                  >
                  >
                  >
                  >
                  >
                  > No virus found in this message.
                  > Checked by AVG - www.avg.com
                  > Version: 2013.0.3349 / Virus Database: 3204/6478 - Release Date: 07/09/13
                  >
                • somaspack
                  Yep haven t got that far because there is no signal... and haven t had time to trace with Dana s excellent circuit analysis. Scott
                  Message 8 of 21 , Jul 11, 2013
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                    Yep haven't got that far because there is no signal... and haven't had time to trace with Dana's excellent circuit analysis.

                    Scott


                    --- In cosmacelf@yahoogroups.com, Dana Myers <dana.myers@...> wrote:
                    > Also, sound card input on most PCs both a mic level and line-level
                    > input, the original
                    > poster would notice pretty quickly if over-driving the mic input :-)
                    >
                    > Cheers -
                    > Dana K6JQ
                    >
                  • Jorgen Nordqvist
                    Found it, thanks Ed. _____ From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf Of ekeefe8051 Sent: Thursday, 11 July 2013 11:57 PM To:
                    Message 9 of 21 , Jul 12, 2013
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                      Found it, thanks Ed.


                      From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf Of ekeefe8051
                      Sent: Thursday, 11 July 2013 11:57 PM
                      To: cosmacelf@yahoogroups.com
                      Subject: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                       

                      Hello,

                      A copy of the ICAN-6934 Application note is in the files section of this group in the "VIP" section. It is the first link.

                      I hope this helps.

                      ED

                      --- In cosmacelf@yahoogroups.com, "Jorgen Nordqvist" <jnord@...> wrote:

                      >
                      > Would love a copy of that
                      application note, if you have the time.
                      >
                      > _____
                      >
                      >
                      From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf
                      > Of /M
                      > Sent: Thursday, 11 July 2013 6:31 AM
                      > To:
                      href="mailto:cosmacelf%40yahoogroups.com">cosmacelf@yahoogroups.com
                      >
                      Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?
                      >
                      >
                      >
                      >
                      >
                      > Ooops! Missed that.
                      >
                      > I happen to have the Applican Note ICAN-6934 'Cassete Tape I/O For
                      COSMAC
                      > Microprocessor Systems'.
                      > Maybe I should run the leaflet
                      in the scanner and share it?!
                      >
                      > Magnus
                      >
                      >
                      >
                      > ----- Original Message -----
                      > From: Dana Myers
                      <mailto:dana.myers@...>
                      > To:
                      href="mailto:cosmacelf%40yahoogroups.com">cosmacelf@yahoogroups.com
                      >
                      Cc: /M <mailto:tubes@...> ; spacewar@...
                      > Sent: Wednesday, July
                      10, 2013 10:17 PM
                      > Subject: Re: [cosmacelf] Re: LM3900 replacement for
                      CA3140 op-amp?
                      >
                      >
                      >
                      >
                      >
                      > On 7/10/2013
                      1:04 PM, /M wrote:
                      >
                      >
                      >
                      >
                      >
                      >
                      >
                      Maybe there has already been this info, but as I recall, the CA3140 was a
                      > FET or even a MOSFET OPamp with almost infinite Zin.
                      >
                      >
                      >
                      >
                      > The original poster corrected himself - it's a
                      CA3401, which was the RCA
                      > second-source for
                      > the LM3900. It's a
                      quad Norton amp.
                      >
                      > Also, sound card input on most PCs both a mic
                      level and line-level input,
                      > the original
                      > poster would notice
                      pretty quickly if over-driving the mic input :-)
                      >
                      > Cheers
                      -
                      > Dana K6JQ
                      >
                      >
                      >
                      >
                      >
                      >
                      > No virus found in this message.
                      > Checked by AVG -
                      www.avg.com
                      > Version: 2013.0.3349 / Virus Database: 3204/6478 - Release
                      Date: 07/09/13
                      >

                      No virus found in this message.
                      Checked by AVG - www.avg.com
                      Version: 2013.0.3349 / Virus Database: 3204/6481 - Release Date: 07/10/13

                    • somaspack
                      It was the CA3401 that was bad. There was also a little bit of trouble with the VIP mono in/out cables correctly jiggling the computer hardware to think there
                      Message 10 of 21 , Jul 22, 2013
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                        It was the CA3401 that was bad.

                        There was also a little bit of trouble with the VIP mono in/out cables correctly jiggling the computer hardware to think there was an input. A stereo 1/8" adapter fixed that.

                        Recording to the computer and the VIP reading back works the same as a cassette recorder. I am using WAV format.

                        Scott

                        > Hi All,
                        >
                        > I spent a few nights working on my old VIP getting it running again.
                        >
                        > One problem persists. I tried to use the tape I/O but that is not operable in sending or >receiving. So it looks like the CA3140 quad op-amp needs to be replaced. These are rather >rare and expensive. This IC is pin compatible with the LM3900, but would it be a drop-in >replacement for this circuit? Thanks.
                        >
                        > Scott
                        >
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