This 1967 modeling circuit mimics the whistle of a locomotive. The steam-shrieking wheezing is set in a 2k2 potentiometer.
This circuit is from the 1993 Motorola Linear Interface ICs. Equivalent operating may be used and...
This reflex receiver was obtained from a 1963 documentation. The transistors are germanium, and...
This linear modulator was found in old documentation. The integrated circuit used is uncommon...