The ZN416E integrated circuit is uncommon today. It consists of a complete radio, like the one found in a 90s Popular Electronics. The power is from a single battery.
This configuration, from a 1976 National Semiconductor manual, shows how to implement a power...
September 2017 - Texas Instruments TPS543C20 Step-Down Converters can be found on Mouser...
This transmitter has a reasonable range despite operating in the 530 to 1600 kHz range. The...