I used a cheap CNC machine to mill the PCB used for this radio. All the components I ordered from Mouser. The boost converter uses an ATTiny microcontroller to act as an oscillator which can be configured to provide different voltages from the boost converter if necessary. I have it set to provide about the maximum voltage, but by adjusting the duty cycle of the output wave you can get different voltages. I didn't have a dedicated SMPS chip available, hence the improvised MCU solution.