This circuit was found in a 90s Popular Electronics. It is used for the acoustic transmitters of 40 kHz, as several found in this section. Transistors support current equivalents.
Found in National Semiconductor publication from the 1980s. This gain-100 circuit can be...
We found this configuration in a 1975 publication. It can be implemented easily, as it uses only...
The high number of transistors on this radio for the medium wave range is an indication of its...