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 decoder TTL circuit for 15-channel remote control was found in Selezione Radio, Italian...
This is the circuit of a sensitive voltmeter using a difficult-to-obtain 5 uA full-scale...
This circuit compares two light intensities, providing the indication on an analog instrument. The...