This circuit is from a 1924 book by Gernsback. The receiver uses two tubes and listens to headphones. Power is supplied by battery with the indicated voltages.
The 4028 CMOS IC not only contains the complete decade counter, but also the 7-segment decoder...
This transmitter has a few watts of output power, having been found in a 1997 documentation. L1...
This circuit, found in US documentation, can measure the power of transmitters up to 10 W, given...