Hi,
I have the nanoVNA2. I'm trying to measure the loss in db between the two ports.
I have the manual but it has nothing on setting the device up for S12 port loss measurement. The manual just tells you where the menu options are. Does anyone have instructions for this type of measurement? A lot of guess work ATM. I see posts on this subject but no settings, just discussion. I could figure this out for myself if I had some calibrated attenuators, but I don't. A couple of observations and some questions below.
What I've done so far:
1. Calibrated the VNA over the frequency of interest. OSL and Through using the supplied cable.
2. Set the displayed marker to LOGMAG.
Q.[LOGMAG is absolute logarithmic magnitude of what value? Power? Voltage? The manual doesn't say]
Q. [LOGMAG of forward or reflected power? The manual doesn't say]
3. Display->Channel>CH1 Through.
With the above settings, I see the display below when a 50cm length of RG142 is connected between the two ports:
CH1 LOGMAG is showing 0.02db. So is that the total insertion loss between ports? That simple?
I'm guessing that the reference level on the chart (0.0db) is one level down from the top, as the yellow horizontal marker (left side) is placed at that level - in the absence of a vertical scale.
Interestingly, when channel is set to 'CH0 Reflect' I see the chart below, -35.19db. There's no way a 50 length of RG142 can have this much loss, so I assume this figure is Return Loss - of the second port termination value?
Thanks.
