This detector uses an unusual sensor today. The circuit is from an 80s documentation. Its sensitivity is 10 ppm. The transformer has two secondary voltages.
We find this circuit in American documentation from the 1980s. The accuracy of the circuit depends on the...
The presented circuit uses a symmetrical power source to supply an amplifier with the LM139 or...
High quality sound can be obtained from this transistor amplifier. The output transistors must be...