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    • #8145
      Guenni75
      Moderator

      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 months, 2 weeks ago by Guenni75.
      • This topic was modified 4 months, 2 weeks ago by Guenni75.
      • This topic was modified 4 months, 2 weeks ago by mwpeters75. Reason: Changed font and size styling for easier reading
    • #8150
      mwpeters75
      Keymaster

      Great stuff Günther!  You are always the premier innovator 🙂 

      Best,
      M.

    • #8151
      Guenni75
      Moderator

      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 months, 2 weeks ago by mwpeters75. 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 months, 1 week ago by mwpeters75. 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
      Guenni75
      Moderator

      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 2 weeks, 6 days ago by Guenni75.
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