Originally designed for WWV (Standard Time Station) signals, it lets 1 kHz tones pass by rejecting the 440 and 600 Hz tones emitted by the station. The circuit is from a 1964 Electronic Design.
This high-gain digital amplifier uses general-purpose transistors. The supply voltage is logic...
Obtained from a 1969 neon lamp documentation, this circuit shows how to assemble an indicated...
This 2-quadrant modulator circuit was found in the May 1988 issue of Radio Electronics magazine. The...