This topic contains 8 replies, has 2 voices, and was last updated by  mwpeters75 1 week, 5 days ago.

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  • #6384

    mwpeters75
    Keymaster

    Professor Frank has been exclusively making contributions to the Lectron.Info forum with many new circuits.  I felt that it was time for me to add one!

    For the 50th anniversary celebration of the Lectron System (1966 – 2016), new blocks were created by Gerd Kopperschmidt using my suggestion of creating an FM Stereo model.  Five new blocks (including #2488 – the block shown below) were subsequently created to demonstrate the FM Stereo technology.  Unfortunately, a new distinct model was never released due to the passing of Mr. Cahn Von Seelen on October 28th, 2016. He was the Lectron System product manager from 2001 to 2016.  A Tech Bulletin was written by Mr. Kopperschmidt however which featured numerous circuits using the new blocks.  A circuit that was absent from the Tech Bulletin was one which featured the use of two speakers.  The circuit below is my offering to fill that gap.

  • #6425

    LectronFan
    Participant

    Hello Michael,

    This seems like a great receiver and deserves certainly a place in the Lectron hall of fame !

    Does the tuner block also has a line output for sound manipulation ?

    Can it also be tuned with an external voltage ?

    Sad to hear that Mr Von Seelen can’t visit this website and forum.

    Lets honour him with your stereo FM radio !

    Greetings,

    Frank

    • This reply was modified 2 weeks ago by  mwpeters75.
    • This reply was modified 2 weeks ago by  mwpeters75. Reason: Changed font and size styling for easier reading
  • #6434

    mwpeters75
    Keymaster

    Hi Frank,

    There is a line output available.  Please see the referenced tech bulletin which is available through the link.

    There is a circuit in the tech bulletin which shows a Lectron System block LCD voltage display.  It allows you to ‘dial in’ the voltage to equate to a desired frequency. The table of these voltages is also in the tech bulletin.

    I hope that Mr. CvS would enjoy the site now.  He never said anything about the Lectron.Info version 1 site.

    We can honor both Mr. CvS and Mr. Kopperschmidt by acknowledging their leadership in bringing the 50th anniversary blocks to fruition.

    Best,
    Michael

  • #6456

    LectronFan
    Participant

    Hello Michael,

    I’ve checked the tech bulletin and the FM module offers quite a lot of possibilities !

    Hmm, I see lots of mods and new circuits around this module 😆

    On the train back home, I had an idea with the FM module 2486.

    Let’s build a FM radio with bass and treble control !

    So back home, I grabbed the Start and expansion set and build an active Baxandall tone control circuit.

    With the upper potentiometer we control the bass tones, the lower potentiometer the high tones.

    The circuit consists of a preamplifier, followed by an active Baxandall tone circuit. The speaker is connected to this circuit.

    The radio module 2486 is very well constructed, it has an amazingly selectivity and sound quality !

    The Lectron team did a marvelous job !

    Here a picture, circuit setup follows later !

    Many greetings,

    Frank

    FM Baxandall

    • This reply was modified 1 week, 6 days ago by  mwpeters75.
    • This reply was modified 1 week, 6 days ago by  mwpeters75.
  • #6457

    LectronFan
    Participant

    Hello Michael and dear readers,

    To honor Mr. CvS and Mr. Kopperschmidt for their realization and Mr. Michael Peters for his idea, I proudly present a FM radio with a Baxandall tone control.

    This active control amplifies or weakens the lower and higher tones. It makes a huge difference concerning sound quality.  This control circuit is often used in amplifiers.

    You can always use the DIN or CINCH connection block and use a mp3 player or similar as input (as seen in the 3-stage amplifier project).

    Thanks to the Lectron system, this circuit is build in no more then 2 minutes !

    Oh yes, I’ve changed the input capacitor C1 into 0,47µF to improve the bass response.

    Here is the diagram, try it out and be surprised !

    Many greetings

    Fm Baxandall

     

    • This reply was modified 1 week, 6 days ago by  mwpeters75.
    • This reply was modified 1 week, 6 days ago by  mwpeters75. Reason: Changed font and size styling for easier reading
  • #6461

    mwpeters75
    Keymaster

    Well done as always Professor Frank!  I did not know that you had some FM Stereo blocks!  Great idea to have tone controls.  May I suggest that you blend the L and R signals so that, while monophonic, you have both left and right music channels? 

    Best,
    M.

    • This reply was modified 1 week, 6 days ago by  mwpeters75.
  • #6486

    LectronFan
    Participant

    Hello Michael,

    Here we have the improved version (V2) of the same radio, L & R are mixed together.

    The input circuitry needed to be tweaked by adding R11 of 5,6K and the overall sound is  !

    Also a new resistor R12 of 220 Ω was added to the Baxandall circuit.

    Here is the diagram for you to enjoy !

    Greetings

    FM V2 Baxandall tone circuit

     

     

    • This reply was modified 1 week, 5 days ago by  mwpeters75.
    • This reply was modified 1 week, 5 days ago by  mwpeters75. Reason: Changed font and size styling for easier reading
  • #6487

    LectronFan
    Participant

    Hi all,

    I forgot to mention that I used a stereo in ear phone as FM antenna.

    Just plug it in the mini jack at the bottom of the FM module.

    Works as a charm !

    Greetings

    • This reply was modified 1 week, 5 days ago by  mwpeters75.
    • This reply was modified 1 week, 5 days ago by  mwpeters75. Reason: Changed font and size styling for easier reading
  • #6520

    mwpeters75
    Keymaster

    Thanks so much Professor Frank!  Excellent use tips as well.

    Best,
    M.

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