This receiver was found in a Popular Electronics from the 90's. Its different configuration shows a tuning circuit after the tube that works as an aperiodic amplifier. Observe supply voltages.
When the illumination decreases, this multivibrator starts up, causing the lamp to blink at a...
The operation of this circuit is old, but the configuration can be elaborated based on modern...
This circuit activates an incandescent lamp when the light stops falling on the sensor. The...