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 circuit was found in a 1974 publication. It provides a tone indication of the temperature sensed by...
This circuit is intended for communications receivers. We can find it in a documentation from the...
This circuit matches a high impedance input signal with a low impedance output. This circuit is...