And since it's sunday and I have time for playing with the NanoVNA, I made measurements to show all of you the effect of placing bypass caps of different value in parallel. Attached are the impedance plots for 100nF alone, 1nF alone, and both in parallel. Whoa! Which option would you prefer?
Note that the 100nF cap alone provides a bypassing impedance below 3? from about 700kHz to about 70MHz. that's pretty good, I would say. The 1nF is bad on low frequencies, and the parallel combination is a total disaster! Yet that's what you will find in equipment designed by people who have never thought about this point, and are just following intuition, which often is wrong...
