This circuit was found in documentation from the 90s. The transistors can be general-purpose equivalents. The circuit has two versions, one that drives LEDs and another that drives a relay as a load.
We found this receiver circuit for modulated light in a 90s Popular Electronics. Equivalent audio...
This field strength meter circuit was found in the March 1968 Radio Electronics magazine. The...
I found this circuit in a 1998 publication, but as all components are common, it can be easily...