This circuit was found in a 1980s American documentation. The data circuit has a low speed, according to the components used. Transistors support modern equivalents.
This circuit was found in an Argentine publication from 1973. It uses a common AM coil (50 + 50...
To obtain rectangular 1 kHz signals, we can have a simpler configuration, with a single amplifier, as...
E) Using a CA3130 this preamp has excellent gain. The power supply does not have to be...