After reading your super regenerative take-up, I give you the following advice:

1. Add 3V three-stage voltage stabilizing IC to replace R 12, and replace C 1 1 with high-frequency ceramic capacitors such as 103 or 472. Because the higher the high frequency power supply voltage, the greater the interference. At the same time, if the high frequency interference of power supply is not filtered, the sensitivity will also decrease;

2. Adjust the resonance waveform of the high-frequency receiving line with the spectrometer. Put the spectrometer near the inductance of L 1 and observe the waveform with the spectrometer. If there are not two lower waveforms, but a higher waveform, it means that there is parasitic oscillation in the receiving line. You must change the resonance capacitance and coupling capacitance, as well as the emitter and collector capacitance of the transistor, to produce two waveforms. Press the transmitter at the same time, so that the waveform of its transmitter just falls on the previous waveform. But it should be based on the actual remote control distance, sometimes in the later waveform. It is best to test the transmitted wave at the peak of two waveforms to see which one is farther.

3. Don't choose an antenna that is too long. If it exceeds 1/4 wavelength, it is even worse.

4, it is best to use PCB cloth board, pay attention to the high-frequency power ground wire and the waveform demodulation and amplification behind, and at the same time, the distance transmission is as short as possible.

5. If the remote control distance is not far enough, you can order 433 high-frequency receiving board and ready-made remote control online.

6. It is best to use a ready-made remote control. If you make your own remote control, please be careful not to change the transmission frequency when holding the remote control.

7. The waveform demodulated by the receiver should be shaped first, not amplified. Because simple waveform amplification will amplify the interference waveform into a data waveform, and make the decoding IC misread as 1 or 0.

We used to use 3V power supply for the transmitter instead of 12V, and the high-frequency circuit of the receiver is the same, but the pulse waveform is arranged. The remote control distance in the field can reach more than 100 meters.

Note that if the car is remotely controlled or the burglar alarm is remotely launched, your remote control distance will be very short.