The two circuits shown show how to obtain an SSB / CW control for receiving this signal top at a common receiver. The circuits were found in an old American manual from the 80's.
This simple CMOS touch switch was obtained in a 1987 publication. All components are common and the...
This Hughes circuit is from 1968. Equivalent modern components can be used. The input impedance is...
This simple demonstration circuit was found in a Popular Electronics of the 1980s. It can be...