We found this circuit in a Radio Electronics from February 1966. The transistor is from the time and so are the transformers. The circuit is battery powered. Observe the impedances.
We find this circuit in a radio amateur publication of 1977. Its purpose is to measure the...
This inverter amplifier is from a 1992 publication. NPN transistors can be BC548 and PNP BC558....
I found this circuit in a 1986 English magazine. It can still be easily assembled, exchanging Q1...