Telephone dialer (CB8521E)

Using an integrated circuit from the time, we found this configuration in a 90s Radio Electronics.

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800 Hz Sine Oscillator (CB25580E)
In this phase shift circuit, the transistor can be any general-purpose transistor. The circuit is from...
Genera-Purpose Alarm (CB10326E)
This simple circuit was obtained from Popular Electronics in December 1990. The magazine no longer...
Oscilloscope Scanning (CB20119E)
This circuit was found in an old American documentation. Its purpose is a proportional scanning signal...