This circuit with only one transistor was found in Japanese documentation from the 1960s. The transistor is germanium, and the circuit has a volume control. The transformer is of the miniature type and the gain is 40 dB.
This circuit with only one transistor was found in Japanese documentation from the 1960s. The transistor is germanium, and the circuit has a volume control. The transformer is of the miniature type and the gain is 40 dB.