This circuit of the 70's uses transistors of the time. The circuit can amplify signals from 10 Hz to 100 kHz and modern equivalent components can be used. The circuit is from Ferranti.
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...