Found on a 1964 CQ this circuit is intended for tone frequency change modulation (FSK) telegraphic transmissions. It operates with signals of 2.975 and 2.125 Hz.
This circuit was obtained from an 80's documentation from General Electric. The circuit uses an...
July 2017 - The new Surface Mount SM0402xx LEDs from Bivar can be found on Mouser. The new...
Found in a 90s American documentation, this circuit that was used in cars of the time, detects low...