Found in American documentation from the 1980s, this circuit rejects strong MW stations that may be interfering with a shortwave receiver.
Featuring low output impedance and high input impedance, this configuration was found in a 1980s...
In the figure we have a TTL logic interfacing circuit as CMOS logic using a 6N139 optocoupler...
We found this circuit in an English documentation from 1989. The integrated circuit used is not...