Found in Motorola's 1967 documentation this circuit can use any general-purpose transistor. The signal should be applied to a good amplifier. The noise diode can be replaced with a common one.
This temperature compensated circuit was found in a Popular Electronics of the 1990s. The circuit...
This LED special effects circuit was found in the February 1992 Radio Electronics magazine. The...
This circuit is part of an oscilloscope project with the PC. Its purpose is to record a peak in a...