On Sun, Nov 3, 2019 at 08:34 AM, <erik@...> wrote:
VNA 1 (nanoVNA) seems at low frequencies to have a Z0 that best matches the
impedance of the cables but shows a substantial deviation above 600MHz
I am new to VNAs, but have wondered during these past few weeks as I experimented with my NanoVNA-H if it is better to calibrate /within/ the 3 bands that use different harmonics.
0-299MHz
301-599MHz
601-900MHz
I suggest this, because I don't know where the Nano switches modes, and staying within the harmonic bands should guarantee that each cal uses a single harmonic. I do all my cals this way, and don't see a penalty, because as a ham, I don't expect to use the same antenna for HF and (example) U/VHF. I think that I need to recal for each geometry anyway, so no point trying to cal to the whole bandwidth.
I see all these traces, and it strikes me that we are looking at a sin(f)*e^(-f)...that is, some sort of sine wave response that decays exponentially. Just a guess...but still wonder what you results would be in each of the 3 Nano harmonic bands.
--
On the banks of the Piscataqua
Rich NE1EE
Rich NE1EE