This commercial receiver from the year 1958 uses two AA cells as Power supply. The circuit is intend to receive MW station and the transistors are germanium types not easy to find today.
This CW circuit was found in a Radio Amateur Today from the 890s. The CMOS circuit must be powered by...
This power supply, found in 2002 documentation, uses fixed 1 A regulators for the power output. The...
We found this circuit in Texas Instruments' Linear Circuits Applications. In the original it is...