This circuit is from old documentation, but it can be implemented with more modern equivalent components. The transistor can be the TIP31 with a heatsink and the 1N4002 diodes.
This is one of many possible metronome configurations using the 555. We found it in an Electronics...
This circuit, for bands above 15 MHz, was found in an Argentine publication from the 1970s. The L1...
Suggested by Texas Instruments, this circuit operates with frequencies that can reach some...