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 amplifier was found in a 1969 Mullard documentation. The circuit uses transistors that have as...
This circuit was developed to test suspect 4001 and 4011 integrated circuits. The circuit is from...
This traditional detector configuration is from an old publication where the MC1555 is the...