Found in a QST magazine from the 90s, this circuit broadcasts on different amateur radio bands depending on the coil. Data for the coil and crystal are provided next to the diagram.
Found in General Electric and 1967 documentation, this circuit automatically turns off the...
This amplifier stage without an output transformer was found in Radio Electronics magazine from...
Found in an Electronics World of 1968 this circuit can use current SCRs and the diodes are...