This commercial circuit is from a Japanese magazine from 1967. It uses germanium transistors, and the coil can be made with 80 to 100 turns of fine enameled wire on a ferrite rod.
In the figure we have an increased dynamic response configuration with the use of a transistor (TR3) in...
This tuned circuit was found in a 1966 Electronic Circuit Handbook. The transistor can be any...
This transmitter for the 40 meter or 7 MHz band was found in a magazine 73 for radio amateurs of...