Carsten,
From your statement, it sounds like you only like OS s/w. Did you compile the compiler you use to create s/w exe's? If you do, what did you use - another compiler? Who compiled that one? How can you trust your compiler - or its compiler - or its assembler if you can't see back to point zero?
Did you inspect the firmware that was already installed in the NanoVNA?
Did you verify that it only provides a serial interface, and that it does not have a hidden HID interface that can inject keystrokes so fast, you'd never notice?
I do computer security and if you're going to be paranoid and not trust just about everything 'out there' you won't get anything done.
How about all the Hams that have created closed source software for the great test equipment they've come up with?
Your statement "Being trusted always creates a liability." just doesn't cut it.
Regards,
Larry
