super simple shortwave receiver circuit


Posted on Feb 4, 2014

Integrated circuit Ul (an NE602 double-balanced mixer) is a combination oscillator and frequency mixer. Signals from the antenna input (at Jl) are fed through dc-blocking capacitor C1 to the RF-gain control, Rl, and fed to the input of Ul at pins 1 and 2. The local-oscillator frequency, which varies with the settings of R2 and L2, is mixed internally within Ul, resulting in an output. The mixer output at


super simple shortwave receiver circuit
Click here to download the full size of the above Circuit.

pin 4 of Ul is applied to a tunable 260-kHz band-pass intermediate-frequency (IF) transformer, L3, tlirough dc-blocking capacitor C7. Therefore, signals that are roughly 260 kHz above and below the local-oscillator frequency are passed while others are effectively blocked. The IF frequencies are now amplified by Q2 and Q3. The AM audio signal is detected by D2 and its associated components, which bypass the RF signals, and leave only the audio signals. The signals are preamplified by Ul -a (half of an LM358 dual op amp). The audio is then boosted to speaker level by the LM386 low-voltage audio power amplifier, U3.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Precision-Increasing Buffer
    Solar Power walkway marker Led display
    500w-power-amplifier-with-2sc2922.html
    Trip Coil Of Circuit Breaker
    Lights Control for Model Cars
    6m wireless remote control switch circuit
    Boombox circuit diagram



    Top