We found this circuit in the June 1987 issue of Radio Electronics magazine. With it, it is possible to receive signals from the bands determined by the crystals in a common medium wave receiver.
This simple musical instrument was obtained from a 1967 magazine. If the original transistors are...
The transistor of this circuit can be the BC558. The circuit is from an old documentation...
We found this circuit in an old American documentation for hams. The circuit serves as a telegraph...