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.
Found in a1969’s neon lamp documentation, this circuit uses a high voltage transistor. The output...
This circuit is intended to match impedances for observing signals on an oscilloscope. The FET...
This circuit, shown in the figure, consists of a variable gain amplifier with differential input...