This circuit is from an1966 General Electric documentation. The Triac can be equivalent to 6 A or more, mounted on a good heatsink. Any diac can be used.
This circuit for the 3.5 MHz band (80 meters) was found in an old radio amateur documentation. The circuit...
This circuit was found in a May 1981 Radio Electronics magazine article. The circuit is offset...
This circuit was found in a 90s Popular Electronics. The circuit operates in the range determined...