The circuit is from an Electronics Hobbyst Handbook from the 90s, being valid for panels of the time, with lower performance. The circuit supplies 2.4V with 125mA current.
The presented circuit emits signals in the FM band, which can be picked up from a distance of a...
I found this circuit in a documentation for radio amateurs from 1975. The FET could be the BF245....
The traditional inverter amplifier configuration with the operational 741 shown in the figure is...