Metronome using operational (CB22060E)

We found this circuit in an English publication. The transistor can be BC549, and the power supply can be between 5 and 9 V.

IR Remote Control – Receiver (CB25094E)
This is the receiver circuit for the previous remote control published in the same Radio...
Fast Peak Detector (CB14063E)
This circuit, for signals up to 1 MHz, is based on an RCA operational amplifier. The circuit was...
FSK Circuit (CB25781E)
This frequency shift modulation circuit was found in the November 1994 issue of Electronics Now...