This Hughes circuit is from 1968. Equivalent modern components can be used. The input impedance is 1000 M ohm.
With the name of transitube we find this MW receiver in documentation from the 50's. It uses a...
This circuit is from a 1998 Electronics Now and can be easily assembled since it uses a common...
This circuit is suggested by National Semiconductor and makes use of the negative regulator LM2990...