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.
The circuit shown in the figure activates a small indicator lamp that will start to flash when the...
The circuit shown is from National Semiconductor's Linear Applications Handbook. The LM3900 is a...
This circuit was found in a 1976 documentation. It can be used with old tape recording mechanisms for...