This circuit was obtained from an 80's Radio Electronics. The circuit decodes “scrambled” or sinusoidal encoded signals by providing an audio signal at the output.
This traditional two-tone alarm configuration with the 4011 integrated circuit was found in a 1998...
This extremely slow circuit produces one pulse per month and can be used in a timer. We found it...
This circuit is from an 80's documentation, making use of PUTs that are not currently common...