This circuit was found in a 1980s documentation for amateur radio. The circuit makes use of components of the era, but modern equivalents can be used.
This touch switch is from a 1978 publication. The circuit should not be powered by a...
The circuit shown uses the 741 operational amplifier, but lower noise and higher gain equivalents...
We found this zener regulator in a 1978 radio amateur documentation. The operational can be...