Lighting detector circuit

This lighting detector circuit it's in fact an receiver tuned to 300 kHz designed to detect the crackle of approaching lightning. A bright lamp flashes in synchrony with the lightning bolts indicating the proximity and intensity of the storm.
The flasher is biased to not flash until a burst of RF energy, amplified by the 2N3904, is applied to the base of the 2N4403. The receiver standby current is about 350 microampers.
To increase sensitivity of this storm detector you must use a longer antenna.
Adjustment of storm detector is very simple : adjust the potentiometer until the flashing is stopped .
When storm detector it's adjusted, the lamp will occasionally flash when big electrical motors or appliances switch on and off and an approaching storm will give quite a show.  Adjust the pot with no antenna if lightning is nearby.