Variable oscillator for code practice (CB7317E)

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

Battery Charger LM317 (CB14307E)
The circuit presented was found in the National Semiconductor Linear Applications Handbook. The...
Frequency Modulated Siren 555 CMOS (CB15868E)
With the circuit shown in the figure we have a frequency modulation which is produced by a...
900 MHz Amplifier THS3491 Using Single Source (CB19657E)
The configurations of the two previous circuits can be modified to operate with a simple power...