This Hughes circuit is from 1968. Equivalent modern components can be used. The input impedance is 1000 M ohm.
August 2017 - New DTMOS Super Junction MOSFETS from Toshiba are in stock at Mouser Electronics....
In the figure we have the configuration of the circuit as a conventional Darlington. In this...
This circuit is from the 80's documentation. The integrated circuit is from the time but can be...