This circuit was found in a 1968 General Electric documentation. It has an input impedance of 2 M ohms and excites a load of 16 ohms. The integrated circuit of the time is the PA237.
Using a new Maxim integrated circuit (www.maxim-ic.com) the amplifier shown in the figure can be...
This 80's circuit uses a small light bulb as an indicator, but an LED with the appropriate resistor...
This transmitter, found in Raytheon documentation from 1957, has a range of a few meters. L1 can...