We find this circuit in American documentation from the 1980s. It consists of a frequency folder using a varicap. The capacitors and coils depend on the frequency of operation.
This circuit can gerenate square signals and be comanded by na external control. When the input...
Hartley oscillator operates in the audio range. Frequency can be adjusted by P1 and also depends...
We find this vibrato configuration with transistors in a 1987 documentation. The components are still...