We found this circuit in the November 1992 issue of Radio Electronics magazine. The circuit has two integrated circuits, one of which is a preamplifier stage. The power supply must be dual.
The transmitter shown can reach around 100 meters depending on the location and sensitivity of the...
This circuit converts a positive CMOS supply voltage to a negative one. We found it in a 90s...
The circuit shown in figure 5 generates square signals based on a transconductance operational amplifier...