Scratch is the scratching noise that occurs mainly with old records. This high frequency noise is eliminated by the filter found in the February 1990 issue of Radio Electronics magazine.
This Radio Electronics circuit, in an 80's edition, decodes the 67 kHz signal used at the time to...
This circuit was found in a 1966 General Electric documentation. The circuit makes use of PUTs...
This circuit was found in an old Electronic Design. It makes use of sidacs and operational not very...