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 intercom uses transistors from the 60s. It was found in a Japanese publication at the time....
A The adjustable Q-factor rejector filter in the figure is based on two LM110. These integrated...
Found in Electronics Now this circuit can generate signals up to a few tens of Megahertz. The circuit...