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    • #8145
      Guenther
      Participant

        First Mr. Birett mentioned an oscilloscope built by Mr. Guerth to visualize the peak when a ferrite core (one part of a ferrite core memory matrix, the very first permanent memory for early computers…) was magnetized.

        I asked later Mr. Guerth and he remembers “his” unit, but he had no schematics or photos. In 2017 – I believe – we found in the archive of RWO the photos of this development – what a surprise!

         

        The used display tube must have been a DG3-12A – this is hard to find and so I purchased the monitor of a VHS camera. My Lectron block looks like this:

        …but to be honest: I have no knowledge how to drive the monitor as an oscilloscope… needed: horizontal / vertical deflection stages, trigger functions and the like… So it’s in my “Incubator” for future developments.

        Meanwhile I purchased a DSO (PRoC) for extreme little money incl. shipping, built a Lectron-like block and did first measurements like this:

        Quite nice, isn’t it?

        The original ready-built unit in a acryl case looks like this:

        Best,

        G.

        • This topic was modified 4 years, 9 months ago by Guenther.
        • This topic was modified 4 years, 9 months ago by Guenther.
        • This topic was modified 4 years, 9 months ago by Michael. Reason: Changed font and size styling for easier reading
      • #8150
        Michael
        Keymaster

          Great stuff Günther!  You are always the premier innovator 🙂 

          Best,
          M.

        • #8151
          Guenther
          Participant

            To complete this topic I built the sawtooth generator (see photo #1) and connected the DSO:

            The DSO display more in detail:

            … and so the oscilloscope display from photo #1 may have been looked like (diameter ~ 2.75 cm = 1.1 inch):

            Best,

            G.

            • This reply was modified 4 years, 9 months ago by Michael. Reason: Changed font and size styling for easier reading
          • #8207
            LectronFan
            Moderator

              Wow Guenther, this looks neat and nifty !

              A perfect add-on for all oscillator circuits.

              You also made a great looking Lectron block for it !

              Greetings

              • This reply was modified 4 years, 9 months ago by Michael. Reason: Changed font and size styling for easier reading
            • #8654
              bodger
              Participant

                Magnetic deflection is tricky, as the deflection coils have significant inductance.  I have quite an assortment of small electrostatic CRTs, I might be able to supply one that’s appropriate if you wish to try.

                I have also been experimenting with magnetic core and have been able to observe the pulse coupled into the sense wire when it changes state.

              • #8664
                Guenther
                Participant

                  Electrostatic CRT – That sounds good, but I am currently being filled with a lot of work, so I may come back to your offer later this (or next) year.

                  Mr. Max Guerth (external “Lectroneer” 1968 – 1971) experimented a lot, e.g. with ferrite core like circuits like this:

                  Best,

                  Guenther

                  • This reply was modified 4 years, 5 months ago by Guenther.
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