This circuit for the 40 MHz band was published in Radio Electronics magazine in December 1957. Its purpose was to monitor the signals of the Russian satellite launched at the time.
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...