This is the receiver for the previous circuit, also found in 90s Radio Electronics. The circuit operates at 2.25 MHz, detecting variations in signal frequency due to the Doppler effect.
The transistor can be the BD135 and this circuit, found in a 1978 publication, can be powered by...
This interesting circuit measures the distortion of the sinusoidal voltage of the power grid. We...
This sophisticated circuit is from a 1975 documentation. The components are from the time and the...