Reflex receiver.
The reflex radio receiver is the one where some stages are used with a double role. In the present case, the assembly made up of transistors T1 and T2 works both as a radio frequency amplifier and as an audio frequency amplifier.
The radio frequency signal selected with the aid of the tuned circuit L1 – C1 is amplified by the two transistors, then after the signal has been detected by diode D1, the audio frequency component is passed through the same stage and amplified.
By using this method, it is possible to save on components and obtain an assembly with superior qualities, under a small volume.