super regenerative receiver circuit

Discussion in 'Wireless & RF Design' started by Omer Terhaka, Aug 30, 2015.

  1. Omer Terhaka

    Thread Starter New Member

    Aug 18, 2015
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    I am trying to build a single transistor super regen receiver I googled it first
    and I found many schematics and topics i read some of them and I picked
    a schematic to build but first i built it in multisim to understand it more
    and test it . right now after simulating it I have these questions so please help

    first as an alternative for the antenna I put an AM signal source connected
    in the way shown in the circuit I include so is that the
    best way to simulate an antenna in a circuit

    second the simulation results for the output shows the oscillation pulses
    but no change neither in the pulses widths or the time between them with the existence
    of the am signal but from what i read this is how the ci rcuit demodulates the signal
    by changing the pulses width or the time between a pulse and another depending
    on the signal amplitude

    finally the circuit responded to almost any frequency I applied to it.



    thanks

    image1.png image1.png
     
  2. BR-549

    Well-Known Member

    Sep 22, 2013
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    A super regenerative receiver is sorta like an analog sampler. Even though the circuit is old, there is still great debate on what is happening.

    Maybe this will help.
     
  3. MikeML

    AAC Fanatic!

    Oct 2, 2009
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  4. BR-549

    Well-Known Member

    Sep 22, 2013
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    "best way to simulate an antenna in a circuit".................no.

    Use mutual inductance.
     
  5. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
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    A few years back, Elektor published a super-regen, the whole project was more than one transistor, but the actual SR stage was a single transistor, AFAICR: it involved a capacitor integrating the straight regen cycles to offset the base bias and achieve quenching. There was an associated inductor that combined with the capacitor for the super-sonic quenching period - the whole thing looked a bit precarious!

    If you want a real easy cheat's way out - just add a simple quenching oscillator to break a straight regen out of oscillation at a rate higher than the hearing range. Needle pulses are good for quenching oscillators, and a programmable unijunction produces nice needle pulses. If you construct the PUT out of a complementary pair of small signal transistors, you can turn the relaxation oscillator any way up you like to get the right polarity pulses.
     
  6. Omer Terhaka

    Thread Starter New Member

    Aug 18, 2015
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    this helped a lot thank you
     
  7. Omer Terhaka

    Thread Starter New Member

    Aug 18, 2015
    3
    0
    i used another circuit with a quenching oscillator and it worked well in multisim so I am goin a hed to build it thank you for the help
     
  8. BR-549

    Well-Known Member

    Sep 22, 2013
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    394
    You might find this interesting also. I never saw a 555 timer used this way before.

    And if you don’t need wide band, you might consider a regenerative receiver.

    I believe there is much potential in processor control of both receivers.
     
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