On Thu, Oct 17, 2019 at 01:02 PM, Dave Daniel wrote:
has anyone measured the +5 V rail(s) to see how noisy they are?
USB power is very noisy.
Hugen79 designed the power part of nanoVNA different from edy555
Hugen79 uses the output of the IP5303 for 5 volt where edy555 uses the USB power.
Did not check noise on IP5303 output but when the nanoVNA is running on internal battery noise is less so I assume its very high frequency noise coming from the USB VBUS, leaking through the IP5303
