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TDA7000 receiver project

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by zachtheterrible, Oct 7, 2004.

  1. zachtheterrible

    zachtheterrible Active Member

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    After a little more experimentation, I've realised that the buzzing can still be heard, disregard my last comment :lol: . I can't turn the CD player all the way up or else the sound starts to distort like mad. Can I fix this?

    I would imagine it's probably as simple as changing the value of the 160k resistor that biases Q1? I just need a better S/N ratio.
     
  2. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Hi Zach,
    I don't think the FM transmitter project causes distortion when its input signal is too high. I think FM radios distort when the FM swings the frequency far too wide. You must keep the input turned down so that the transmitter isn't any louder than a radio station. Also, maybe your CD player distorts when its volume control is at max.

    Don't change the biasing of Q1 by changing the 160k resistor, or it will saturate or be cutoff and really distort the sound. Just remove R1 and make an attenuator at the input with a series resistor maybe 2.7k from the CD player and a resistor to ground maybe 100 ohms.

    Didn't you use a mixer made from two joined resistors to add the left channel with the right channel? Then they could be the 2.7k part of the input attenuator and also need the 100 ohm resistor to ground.
     
  3. weijie

    weijie New Member

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    i got some problem while doing this circuit . my circuit are able to tune at the range of 60Mhz to 108Mhz at the local oscillator (pin5 and 6).
    how ever , the frequency at the antenna pin will change when i varying the local oscillator capacitor . Is it correct ?
    wat is the expected value of antenna pin ?
     
  4. dave

    Dave New Member

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  5. Warlord_1011

    Warlord_1011 New Member

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    I am trying to make the circuit, printed on the datasheet, how could i make the 56nh coil?, what diameter former etc, or could i just buy a inductor from somewhere?

    Datasheet:
    http://www.datasheetcatalog.org/data...7000_CNV_2.pdf
     
  6. mustafax_001

    mustafax_001 New Member

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  7. Hero999

    Hero999 Banned

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    Isn't the TDA7000 obsolete?
     
  8. transistor495

    transistor495 Member Forum Supporter

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    TDA7000?

    Does anybody use this IC to assemble FM radios anymore? A TEA5710/11 is much better.
     
  9. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Wasn't the TEA5711 AM/FM stereo radio IC used in Patrick Cambre's project? It is also obsolete now and not made anymore.
    A similar IC is in my Sony Walkman portable radio and it is also not made anymore.
     

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