The tone generated by this bell changes when we press and release the switch. The circuit is from a 1985 Radio Electronics. Some changes can be made to improve its performance.
This drain dip oscillator was found in an old English documentation. The JFET can be of any type...
This SCS counter circuit was found in a 1964 General Electric documentation. The circuit has a...
This is the circuit of a commercial radio from the 60s, sold in Japan. The circuit shows the...