This 1.5W tube amplifier was found in an American documentation from 1947. It is a direct rectification circuit without the need for a power transformer.
This small general purpose and RF transistor tester appeared in a February 1958 Radio Electronics...
The MC4741 integrated circuit consists of four operational amplifiers similar to the 741 in a...
We found this touch control on a Popular Electronics from 1970. The circuit makes use of an...