Wien Bridge Oscillator (CB8093E)

This circuit was found in a Popular Electronics from the 90s. Transistors admit equivalents, as well as the operational.

Operational Oscillator (CB5915E)
We have in the figure a traditional amplifier configuration with operational amplifier. The source...
10 s to 10 m sequential timer (CB1519E )
This circuit was found in a 1977 Radio Shack documentation. The circuit is TTL, which must be...
Modulator with TAA111 (CB19432E)
This circuit is suitable for modulating small FM transmitters for eavesdropping or espionage. The...