Obtained from an English publication in the 1980s, when a weather station operated in that country at 60 kHz, this circuit employed only two general-purpose transistors.
This is a commercial circuit from the year 1958. Transistors are germanium types and transformers...
This circuit is from an English documentation from 1968 but can be assembled with modern...
We found this circuit in an American publication in 1975. The circuit generates an adjustable...