We found this precision circuit in a manual from the 80's. The operational amplifier is of a common type at the time, and equivalents can be tested. Transistors are general purpose types.
So This circuit was published in a 1982 English magazine, but can be easily assembled using BC548 for...
With this circuit it is possible to tune an AM signal using a 5k potentiometer (4k7). The circuit was...
This power source was found in a 1968 Electronics World. The transistors are from that time. The...