This small 1W turntable amplifier was found in the 1975 RCA tube manual. It is a commercial circuit at the time.
The sensor is an NTC and in the connection as shown in figure (a) we have the trigger with the...
This oscillator configuration with the operational 741 was obtained in a European documentation from the...
Found in Motorola's 1965 manual, this full-wave dimmer controls a load that depends on the used...