Found in a QST magazine from the 90s, this circuit broadcasts on different amateur radio bands depending on the coil. Data for the coil and crystal are provided next to the diagram.
This traditional circuit generates a 200 Hz sinusoidal signal. The frequency depends on the...
This circuit supplies a continuous voltage at its output, which is the peak value of the...
This circuit is suggested by National Semiconductor and has an excellent gain, for a photodiode as a...