TBA120 Demodulator Circuit


Posted on Feb 5, 2014

The TBA120 Series ICs provide a high-gain limiting IF amplifier and a quadrature coincidence detector in one package. These ICs are primarily intended for extraction of TV intercarrier sound, which (in Europe) is frequency modulated onto a 5. 5MHz or 6MHz subcarrier. The TV waveform constitutes an extreme interfering signal, and the TBA120 provides


TBA120 Demodulator Circuit
Click here to download the full size of the above Circuit.

superior performance in comparison to early Foster-Seeley and Ratio Detector systems, with a considerable reduction in component count. TBA120 as AM demodulator. Equivalents are SN76660N (TI) and S041P (the latter is a low power version). It is in fact a CW/SSB/AM-multimode-detector, but the BFO line is connected to the signal from the IF. Believe I tested it in my Drake 2-B. Please note that TBA120AS, TBA120S, TBA120C, TBA120D etc are different and may not function satisfactorily in this construction. It is also suggested the change for use as SSB detector, but it is an old device and the circuit has more interest as a reference IF level is supposed to be maximum 50mV RMS. MC1351 should not have more than 10-20mV, and TDA1576 is overloaded with higher levels than 100mV RMS. NE/SA604/614 could also well be used, but have not been tested. The TBA120U is an i. f. amplifier with a symmetrical FM demodulator and an a. f. amplifier with adjustable output voltage. The a. f. amplifier is also provided with an output for volume control and an input for VCR operation.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Power Amplifier 2x30W
    Saw-oscillator-modulator
    Infrared beam barrier proximity sensor
    Honda Motorcycle CB400 (Hawk II) Wiring Diagram
    CVS Oral Thermometer Dissection
    Audio Filters Circuits Projects
    Driving a fluorescent tube
    LED sequencer
    TMB-1 Tri-Mode Buffer Amplifier Box
    1kHz square wave signal source circuit
    AC contactor silent operation of the circuit
    Key Code Combination High Security Door Lock



    Top