The solid-state Armstrong regenerative receiver

The Armstrong circuit has also its solid-state counterpart, and historically speaking, it
has been devised using bipolar transistors as well as junction FETs (JFETs) and
insulated-gate FETs (IGFETs or MOSFETs).

There is an important difference in the detection action of the solid state version. We
shall base our comments on the Armstrong receiver shown in Fig.3 that will tune the
530kHz~1700kHz MW AM broadcast band.