This oscillator uses a small IF transformer taken from an old transistor radio. FET admits equivalents. The circuit can be used to calibrate radios.
This circuit detects signals in a wide range of frequencies, indicating their strength in an...
This traditional two-tone alarm configuration with the 4011 integrated circuit was found in a 1998...
This circuit was found in the June 1980 issue of Radio Electronics magazine. The circuit uses an...