This circuit is from an 80's publication. It makes use of small 6 V x 50 mA incandescent lamps. The diodes can be general purpose or even 1N4002. The transformer is 6.3 V with 100 mA or more current.
This voice scrambler circuit was obtained from an American 1990s documentation. Used operational...
August 2016 - The new Schottky diodes from Vishay's ESMP series for surface mounting can now be...
September 2017 - Texas Instruments PCM186x and PCM186x-Q1 Audio ADCs can be found at Mouser...