This transmitter for the 3.5 and 7 MHz ham radio was found in a 1950s Japan publication. No information was given on the coils and the power supply.
This circuit is in the very datasheet of Texas Instruments that manufactures the component...
This interesting two-transistor detector is characterized by high selectivity. The circuit is from...
This circuit makes use of older operational amplifiers, but can be designed on the basis of modern...