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    • #5989
      mwpeters75
      Keymaster

      Fellow Lectroneers, courtesy of Günther Stabe, here is an excellent overview and a series of recommendations for cleaning and maintaining legacy Lectron System parts to like-new condition.

      In addition, Frank has also pointed to a YouTuber (8 Bit Guy) who offers recommendations on restoring yellowed plastics back to white.

      Ground Plates
      Block Remediation
      White Covers
      Magnets
      Block Contact Plates

      Ground Plates
      One of the more typical issues confronting the legacy Lectron System model purchaser is a blemished and ugly looking ground plate, especially common for the Egger and Braun ‘deluxe’ ground plates. This process will also work on the ‘economy’ ground plates (for example, those found in the MiniSystem, Buchlabor, Kimber, and Raytheon Series 1-3 models).

      Günther’s cleaning process is as follows:
      1. Use masking adhesive tape to cover the plastic parts.
      2. Apply sandpaper (very fine ones, here: 400 particles of corundum per cm² ) to clean the metal surface until it is absolutely clean and shiny.
      3. Use some steel wool or other fine polish material to get the silky finish – if required and available.
      4. Apply chemical contact cleaner (for radio and TV) to achieve good electrical contact between the individual blocks and the ground plate. Simply spray and wipe clean with a cotton buffing cloth.
      5. Make sure to use rubber or latex gloves to prevent the hands from getting black because of the surface residue. See residue on the buffing cloth in photo above.

      Once you have completed the cleaning process, your ground plate should look like new. A clean ground plate is ESSENTIAL to ensure a reliable electrical ground for the Lectron System circuits.

      The end result will be a superior electrically conductive ground plate despite the burnished look finish.

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      Block Remediation
      There were two types of block covers – the first type used in the earlier Egger Lectron systems had a glued on top white cover.  This would make the cover’s removal difficult for internal block repairs – soldering of welds and component replacement. The second type of white cover (shown below) featured two nubs and sockets diagonally across from each other.  This enabled the cover to be removed and then restored after effected repairs with little risk of damaging the block or cover.  With either cover, the use of a glue geared toward plastics (other glues can cause physical damage (‘melting’) can be sparingly applied to two of the corners.  Do not over glue!

      The contact plates may also need to be remediated, especially if pitting has occurred.  Replacing contact plates can be done but sometimes it is just simpler to use a replacement block. Make sure to examine the contact plates on the bottom of the block as well.  The cleaning process for the contact plates is reviewed below.

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      White Covers
      Unfortunately, long term exposure to sunlight can discolor the white covers resulting in a light yellow color. This cannot be corrected other than by replacing the cover. Long term storage conditions can also discolor the white covers. Where possible, avoid leaving the blocks exposed to sunlight or UV light and store the units in a temperature controlled environment.  

      The white covers can also become dirty or show black or dark grey spots.  Fortunately, there is a great solution for that problem.

      This problem can be corrected by a careful application of a surface cleaning product such as the American made ‘Dash Away‘. Be careful not to overly scrub the schematic symbol itself.  The result:

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      Magnets
      Yet another vulnerability that occurs over time is due to how the larger size bottom magnets were secured inside the clear block case. A combination of tabs, glue, and sometimes a piece of clear tape were used. As the plastic aged, the tabs became brittle and broke, releasing the magnet inside the case. After 30 to 40 years, both the tape and the glue would lose their ability to hold the magnet in place if the tabs failed. The Pattex glue product shown in the last graphic below is a suitable glue to resecure the magnet to the base.

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      Block Contact Plates
      The small contact plates on the block sides and bottom can also get corroded, pitted and/or blemished. Remediation can be done in a similar manner to the ground plate but smaller burnishing tools are more appropriate.

      Some of the German cleaning products that Günther has used successfully.  There are of course similar products available in any other country.

      You will have good luck with restoring your legacy Lectron System to its physically pristeen appearance with excellent electrical conductivity at all the needed connection points by following the above cleaning procedures.

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      • This topic was modified 2 months ago by mwpeters75.
      • This topic was modified 2 months ago by mwpeters75.
      • This topic was modified 2 months ago by mwpeters75.
    • #6302
      LectronFan
      Participant

      Hi Michael,
      This is a great tutorial how to restore a Lectron system like new!
      Clean contacts are a “must” to achieve flawless operation of a circuit.
      Greetings

      • This reply was modified 2 months, 1 week ago by mwpeters75.
      • This reply was modified 2 months, 1 week ago by mwpeters75.
      • This reply was modified 2 months, 1 week ago by mwpeters75.
    • #6316
      mwpeters75
      Keymaster

      Absolutely agree Frank!

      Some of the legacy acquisitions from an eBay source can have various components or parts needing this remediation.

      Best to all Lectroneers,
      M

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