This frequency shift modulation circuit was found in the November 1994 issue of Electronics Now magazine. The circuit operates at low frequencies.
This simple Philips circuit from the 1960s can use any general-purpose transistor. The signal is...
This transmitter for the 80-meter band (3.5 MHz) was found in an old documentation for radio...
Found in a 1965’s Electronic Design, this circuit operates with a voltage of 1.5 V. The relay can...