We found this circuit in a Radio Electronics from October 1963. The circuit uses an output transformer with a center tap. The trimpot is adjusted for higher gain and lower quiescent current.
April 2017 - The new Recon Jet ™ Pro which is Smart Glasses from Intel® can be obtained from...
This one-transistor alarm can be used with much more sensors than the two shown by the figure....
This Popular Electronics circuit can be found in various versions on this site and in this...