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.
Today we have more compact solutions. This is from a Radio Electronics magazine from October 1990....
This oscillator was found in a 70s RCA linear circuit manual. The oscillator makes use of an...
This is a commercial circuit from a Japanese publication from 1972. The circuit uses a FET that...