This circuit was found in a Hughes manual of 1068 using a MOSFET of the time. The circuit can be adapted to use modern equivalent MOSFETs.
The microphone for this circuit, found in a 1967 Japanese documentation, must be ceramic or...
The integrated circuit used in this regulator is not very common today. The circuit is from old...
The diodes of this circuit are general-purpose, and the base resistors are typically between 2k2...