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Hello, can somebody help wich transistor is like bfg520

Discussion in 'Radio and Wireless' started by michael1978, Jul 27, 2018.

  1. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    I donw know man, i try,but does not work, can you help me please, i donyt kn
     
  2. Audioguru

    Audioguru

    2,345
    516
    Sep 24, 2016
    It is extremely easy to see how to fix your mistakes:
     

    Attached Files:

    michael1978 likes this.
  3. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    You are a genie, i go little bit outside with my children after i gonna fix it, thank a lot mister profesionist
     
  4. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    HE DOES NOT WORK :( 2.png
     
  5. michael1978

    michael1978

    388
    2
    Mar 17, 2012
  6. Audioguru

    Audioguru

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    Sep 24, 2016
    1) You have the audio output of the radio tuner shorted directly to +12V. Then there is no audio and the LM386 will be destroyed.
    2) The simulation program needs a model of the LM386 and you must show its pins numbers on the schematic.
    3) R4 is not needed but you need a volume control.

    The inductance of L1, L2 and L3 are all the same. It is strange that you have L1 tuned with 170pf but you also have L2 plus L3 in series also tuned with 170pF then their resonant frequencies are completely different. Most Foster-Seeley discriminator circuits on the internet have variable capacitors so that they can all be tuned to the same 10.7MHz. Shouldn't the value of C3 be half of 170pF which is 85pF?
     
  7. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    look i change why he dont work now now
    2.png 22.png
     
  8. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    Sorry that i disturby, what for wrong now is circuit can you help please is almost finish
     
  9. Audioguru

    Audioguru

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    516
    Sep 24, 2016
    Do you know what is a "model" of an LM386? it has all the specifications so the simulation program knows its input pin numbers, how much voltage gain it has and how much output current it has.

    I think your sim program does not have a model of an LM386.
    Disconnect C8 from the LM386 and have your sim program look at the output of C8.
     
  10. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    I see simulation, but i get some strange picture, i dont know is correct of now, how must to sffm 2V 10.7MEG 50 1KHZ Right,
     
  11. Audioguru

    Audioguru

    2,345
    516
    Sep 24, 2016
    You have 0 30Mm 10.7Meg 50 1000 in SFFM:
    1) The sim program does not know 30Mm which should be about 500mV.
    2) The 50 is the modulation index that should be 2000.

    You also have an AC command that should be removed because it shows the frequency response of
    something. The sim program cannot make an FM signal SFFM and an AC frequency response at the same time.
     
    Last edited: Aug 21, 2018
  12. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    Goodmornig Audioguru, with or without ac i try get this result, how can i see that i demulate one signal?
    2.png 22.png
     
  13. Audioguru

    Audioguru

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    Sep 24, 2016
    Your LM386 is a mess and I think your simulation program does not know what it is. Delete it and have the sim program show you the signals at C8.

    You have C4 and C5 at 0.01uF which is 10,000pF. All other discriminators and your old ones have 200pF.
     
  14. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    This is signal out from C8, make C4 100pF and C5 = 100pf E DISCONNECT LM386 THIS THE FOTO HERE 2.png
     
    Last edited: Aug 22, 2018
  15. Audioguru

    Audioguru

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    Sep 24, 2016
    Your "oscilloscope" timebase is very fast at 0.5us per division and shows a tiny 5MHz waveform on top of a much lower frequency. To see the 1kHz demodulated waveform then the timebase must be much slower at maybe 1ms per division.
     
  16. michael1978

    michael1978

    388
    2
    Mar 17, 2012
     
  17. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    HI Audioguru, i can do it only with 10mV(when i try 600mV 700mV i take ouput like the other one line sharp) input sffm, and i get this, can you tell me is demulated is normal good working, second picture i zoom it, with input signal 2.png 22.png
     
    Last edited: Aug 22, 2018
  18. Audioguru

    Audioguru

    2,345
    516
    Sep 24, 2016
    Why are you making a simulation when you do not understand how to set up the simulation?
    The "timebase" for the oscilloscope of the simulator is set with the TRAN command. Here is how to set TRAN (right click on it) to show the 1kHz demodulated waveform on C8:
    Stop Time: 100m
    Time to start saving data: 95m
    Maximum Timestep: 10m
     
  19. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    Thank y
    Hi AudioGuro is posibble another methode faster, i have to whait 100M or 1hour and half
     
  20. michael1978

    michael1978

    388
    2
    Mar 17, 2012
    i whait almost 1hour 60MINUTES, why hi take so long i dont understand, wich formula of osclliscop is that?
     
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