We found this circuit in a 1991 Hobbyst Electronics. The circuit makes use of an unusual transducer today. It is a piezoelectric buzzer that can eventually be replaced by an equivalent configuration.
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...