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.
In the original version of this 1987 circuit, the loads are lamps, but it can be adapted to drive a...
We found this circuit in a Radio Electronics from the 90s. Transistors admit current equivalents,...
This CMOS frequency meter can measure frequencies up to about 1 MHz with a 3-digit resolution. The circuit is...