The power supply for this 1972 circuit must be symmetrical and the BC549 transistors. Care with the layout is important to avoid capturing tinnitus.
This circuit operates at the frequency of a small transmitter up to 27 MHz, triggering a relay from...
This medium wave radio with 7 germanium transistors was manufactured in Japan in the 1960s. Its...
In the figure we have the way to implement a power zener diode. The voltage depends on the zener,...