We found this circuit in an old documentation, but it is still current. General purpose transistors can be used, and the SCR can be the TIC106. The bell is a transducer with an oscillator (buzzer).
To divide by an odd number‘ means not only the need for flip-flops, but some additional logic too. The...
This circuit, from a 1975 technical documentation provides a gain of 14 dB at signals from 500 kHz to...
This circuit was found in American documentation from the 60's. The transistors are made of...