This 4-transistor amplifier can work from 4.5 or 6 V power supplies. We found it in a Mullard transistors manual from 1960. The transistors are from the time.
Similar circuits can be found on this site. This is from an 80's American documentation. The...
This circuit is from a Radio Electronics magazine from July 1984. The transistor determines the...
Measuring capacitances and resistance this simple instrument was found in Radio Electronics...