How much power does such a radio need? At what voltage (or just I and U)?
Ever since USB-C powerbanks with up to 20 V from PD are a thing, I use them for as much as possible.
How much RFI do those power banks spew out?
USB PD only goes up to 3A at 15V. That’s not enough current to run a mobile radio.
A small LiFePO4 battery is a much better choice as it will supply a stable 12.8V without any switch mode supplies.
@AG7LR
@Eheran This is incorrect. USB PD does 20V 5A (100W) with the common 3.0 version. 3.1 increases that to 240W using higher voltages. https://www.usb.org/usb-charger-pd
Most radios won’t run on 20V or higher. At 15V or lower, USB PD is limited to 3A.
If you wanted to get 100 watts, you would need a buck converter to step 20V down to 13.8V. Now you have two switch mode power supplies producing RFI.
@AG7LR Ah I see what you meant now. It is possible that PPS could be used to achieve 15V 5A depending on the power bank's PPS limitations and cable used. But with a well-designed switching PSU that can accept PD 3.1 voltage ranges and output maybe 14.2V to keep radios at a more common voltage level, I think noise would be minimal and the convenience of using USB-C would be nice. I already use 12V/3A PD setups for HTs and QRP radios.