We found this tube receiver in a 1950s Japanese publication. The circuit uses 5 tubes and has an RF amplifier stage for greater sensitivity. The power supply is not shown on the circuit.
We found this circuit in an old Mullard (Philips) documentation. The sensor consists of a...
This simple circuit, powered by 4 batteries or 9 V battery, brings together several functions of...
This circuit was found in an American documentation from 1977. The mechanical resonator or ceramic...