Variable oscillator for code practice (CB7317E)

This circuit is from Popular Electronics from the 90s. The integrated circuit is not very common nowadays.

OSEPP Sensor Modules
Several types of OSEPP sensor modules can be obtained from Mouser Electronics for Arduino...
Epcos TDK TB2569 Film Capacitor
Epcos TDK TB2569 Film Capacitor EPCOS / TDK offers through Mouser Electronics are line of film...
Low power current sensor (CB5382E)
This circuit was obtained from a 2005 Linear Technology application manual. The circuit is...