TDA7000 Chip - FM Radio

Discussion in 'General Electronics Chat' started by Shelton, Mar 21, 2008.

  1. Shelton

    Thread Starter Member

    Mar 13, 2008
    19
    0
    Hi All

    I have a question regarding the TDA7000 chip. In the specification sheet, it says the RF input frequency range is 1.5MHz to 110MHz.

    Is it possible to take a chip like this and pick up RF in the range of say
    120-130MHz by using external LC components?

    Or will the chip just wont work in this spectrum ?

    Regards,
    Shelton.
     
  2. scubasteve_911

    Senior Member

    Dec 27, 2007
    1,202
    1
    As the datasheet says, you cannot use the IC for your task. In order to bring a higher frequency down to the range of the IC, you have to 'downconvert' it. It may not be practical to do this, so you should look into an IC that will work.

    http://en.wikipedia.org/wiki/Downconverter

    Steve
     
  3. Shelton

    Thread Starter Member

    Mar 13, 2008
    19
    0
    Hi Steve

    Do you know of any chip that will work in this range - i mean like the TDA7000 - but can grab RF in the 120-130MHz range ?
     
  4. scubasteve_911

    Senior Member

    Dec 27, 2007
    1,202
    1
    I'm sorry, I don't really know off hand. I'd have to take a look around.. All I know is that for non-standard ranges that they haven't made ASICs for, you need to downconvert with a LO to a standard IF where you would demodulate using a standard IC.

    Steve
     
  5. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    The TDA7000 is obsolete and is not made anymore. There are newer similar ones that use "scanning" for tuning.
    Their performance is horrible. They might pickup local FM stations but they fade in and out because the sensitivity is poor and local stations overload them. The distortion and noise is high.

    In the 120-130MHz range are aviation AM narrow band communications, not wideband FM.
     
  6. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Just don't try to make a superregen radio. :rolleyes:

    Or if you do decide to do so, ask questions about them elsewhere. We've had quite enough of them lately, thank you very much.
     
  7. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    The old TDA7000 "radio" has a 70kHz IF frequency with its tuning by RC filters.
     
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