This circuit is used in VHF and UHF superheterodyne receivers. The circuit is from the 1964 RCA transistors manual. Equivalent transistors such as the BF495 can be used.
Placed in the vicinity of a telegraphic transmitter (CW), this circuit produces an audible signal on...
Damped oscillators can be used to produce sound from percussion instruments such as the triangle, bell,...
We found this circuit in a 1983 English magazine, but it can be easily assembled with the BC548...