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.
This simple multimeter takes advantage of the low cost common galvanometer of 200 uA or 1 mA and...
In the figure we have the way to use an operational amplifier on a higher voltage source than it...
This crystal-controlled oscillator was obtained from an American 1980s documentation. The circuit...