This circuit is from a 1968 publication. Here we have several types of resistive sensors with individual adjustments triggering a single SCR. Power depends on the type of sound device to be triggered.
Placed near a common receiver, this oscillator is intended to generate a beating signal to receive...
CMOS integrated circuits are sensitive to supply voltages in terms of signal propagation time....
Found in a radio amateur magazine of the 1980s, this circuit uses components that can still be...