This circuit was found in the June 1991 issue of Radio Electronics magazine. The circuit uses two Hall effect sensors of the time. It can be assembled using modern equivalents.
In the figure we have the shot made by an interrupted light beam using a phototransistor or a...
Using a CA3130 operational amplifier, this circuit from a 1977 documentation can handle low...
This is the receiver for the CB1364E transmitter. Other receivers can be found in this section of...