FM receiver TDA7000 continuous loop scan

Discussion in 'The Projects Forum' started by brickman7, Sep 29, 2013.

  1. brickman7

    Thread Starter New Member

    Sep 29, 2013
    1
    0
    New to electronics design, computer tech needs a schematic based on the simple TDA7000 ic to continuously scan through the frequencies! I have the TDA7000s, and YDA9088s but they are surface mounts. I can get most older ICs from a supplier in China so I'll take suggestions. I just need it as simple as possible. I have TDA2822s for amps, but I can get what is needed. I also have BB910 varactor diodes.

    I just need an fm scanner to scan thru the frequencies and not lock on a station without having to be reset to continue scanning. And output thru an earphone and speaker. Also, I do not want to mute the scanning process. I need to hear the white noise as it scans.

    Thanks!
     
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    5,003
    745
    Here is a circuit of a TDA7500 receiver using a varicap diode, you need to put a sweeping dc voltage instead of the wiper of the 100 k tuner pot, to scan through the wave band.

    I would remove the 100k preset and use a triangle wave ramp generator like a 555 timer set to .1Hz to 0.5hz and buffer the the voltage across the charging cap to feed into the varicap diode.
     
    Last edited: Sep 29, 2013
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