Digital recorder ISD1016 (CB7963E)

Found in a Popular Electronics from the 90s, this digital recording circuit uses an unusual integrated circuit today.

Sound Voltmeter (CB25975E)
This circuit was found in the September 1996 issue of Electronics Now magazine. The sound provided has...
100 MHz Oscillator (CB23729E)
We found this circuit in a March 1961 Radio Electronics magazine. This circuit reaches 100 MHz...
28 to 5 V Converter (CB26336E)
Using the M1575 this switching converter was found in National Semiconductor documentation from...