This circuit was found in an English publication from 1967. The circuit is for listening on a phone. Transistors are types of germanium of the time.
This circuit can be used with 3 receivers and is intended for low frequencies (medium wave range). We...
This electronic voltmeter circuit was found in a documentation from the 50's. The sensitivity is...
This battery-powered micropower supply was shown in Radio Electronics magazine in 1991. The...