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.
We found this circuit in a Popular Electronics from 1992. It consists of a voice scrambler used in...
This dual power supply for power amplifiers with a voltage of 40 V and a current of 3 A was found...
Found in a publication from the 60's, this power supply has no regulation, but only current...