This is the receiver for the previous circuit found in the November 1991 Radio Electronics magazine. The frequency is 2.2 MHz determined by the coils.
Found in a 1963 documentation, this circuit employs germanium transistors of the time. Transformer and...
In the figure we have a way of receiving ultrasonic signals of a single frequency using a PLL 567....
This traditional circuit generates a 200 Hz sinusoidal signal. The frequency depends on the...