The transistor used in this circuit is uncommon today. AC124 or equivalent such as AC188K and 2N2431 can be used. The circuit is from the 80's and makes use of transformers.
September 2016 - Mouser Electronics is providing new ultraviolet LEDs VLMU1610 of Vishay suitable...
This circuit is from a 1968 documentation using one of the first integrated circuits available at the...
We found this circuit in a publication for radio amateurs of 1976. The operational amplifier is a...