Review on 📻 Zerone Airband Radio Receiver: DIY Kit - High Sensitivity 118-136MHz AM Aviation Band Receiver by Ronny Prather

The DIY kit has some small problems. Additional resistance 4.7K. There is no 10K resistor. Wrong circuit on the IF transformer T1 10.7 MHz. Invalid values for CP9 and CP10. Declared 10uF, should be 100uF. Modified kit to run on internal 9V battery and external 12V DC power supply via selector switch. So U1 was replaced with an LM7805 with two iN914 diodes in series to ground to provide 6.3 VDC for the receiver circuitry. For better sensitivity, the resistor R3 270 ohms is omitted. For additional audio gain to drive a small speaker, a 10uF and 470 ohm resistor has been added between pins 1 and 8 of the U6 LM386 audio amplifier. As the tuning voltage range is now reduced, R21 is reduced from 3.3kΩ to 1.5kΩ and a 10pF capacitor is added to C14 to give a tuning voltage range of 118-136MHz. When the squelch is open there is no background bandpass noise. Changed R22 value from 470K to 4.7K, noise gate works now. The work is satisfactory. The circuit is stable with no distortion.