This 2-tube amplifier was found in a Japanese publication of 1964. The circuit has excellent sound quality. The power supply is not given and must provide a voltage of 300 V.
When the temperature rises above the value adjusted by P1 the relay triggers on. The rated voltage for the...
This oscillator for frequencies up to a few tens of kilohertz was found in a 1970s documentation. The...
This small transmitter, found in a 1982 publication, sends its signals to an FM receiver placed...