This circuit is intended to switch high frequency antennas using common diodes. The circuit is from an 80's documentation appearing in other versions in this same section of the site.
July 2016 - It can be obtained from Mouser Electronics new trinkets Adafruit. These trinkets are...
This circuit allows you to read resistors up to 20 M ohms, converting it into voltage. The circuit is...
In fact, this is the circuit also known as “vox”, that is, a relay triggered by sound. This...