The idea of this circuit found in a Radio Electronics from January 1966. The idea of the circuit is to improve the reception of audio signals, mainly telegraphy, working as a filter.
The circuit shown in the figure is suggested by Texas Instruments and allows data transmission on TTL devices...
We find this vibrato configuration with transistors in a 1987 documentation. The components are still...
This circuit, from a documentation from the 1970s, produces two sinusoidal signals given by C2 and...