This circuit with the HA2400 was found in the March 1980 Radio Electronics magazine. The circuit has digital-gain control and must be powered by a symmetrical 15 V source.
This circuit was found in a Signetics documentation from the 1980s. The integrated is a PLL and...
This two-channel wired intercom was found in the April 1990 issue of Radio Electronics magazine....
The output voltage of the circuit shown in the figure is approximately 7.0 V for a 15 V supply...