This circuit was found in an Australian publication from 1991. It is a transmitter that transmits a signal when it detects moisture. The range is on the order of a few tens of meters.
We found this sensitive moisture detector in an old documentation. The circuit uses a common JFET,...
This circuit, with the assembly in a contact matrix, was found in a publication from the 90s. The...
This modulator circuit for transmitters was found in American documentation from 1964. It can be...