This circuit is from an American 1967 documentation and can be implemented with modern equivalent transistors. The circuit serves as a Q multiplier.
This traditional crystal CMOS oscillator circuit was found in a 1990 Electronics Handbook. The...
This version of a call-fish is from 1981 using, for this reason, a 90 V battery that is no longer...
This signal strength meter (S-meter) was found in a 1975 amateur radio publication. We can use...