This circuit is from an ancient American documentation. The integrated circuit is 741 and the power supply must be symmetrical. The passing band is centered at 1 kHz.
Although the BD135 transistor is not specifically for RF applications, some of them can easily...
This transmitter for modulated radiation can be used as an optical data shield. The maximum...
This ultra-low noise circuit was found in the May 1990 issue of Radio Electronics magazine. The...