This circuit that draws 1 out of 8 LEDs was found in an 80's American documentation. The circuit can also work with an astable using the 555 instead of the 4046 which is not a common component today.
This field strength meter for the 11-meter range was found in Radio Electronics magazine from...
The output stage of this amplifier can operate at high voltage. The transistor must be a high...
This article is from an old publication from 1978. The transistor can be a BC548 and the power...