Hello Kurt,
Thank you very much for your paper How_to_display_delay_shift_for_a_cable_in_NanoVNA_saver.pdf
I tried to follow your advice.
By reviewing all Display Parameters of nanoVNA-saver I brought it to about your style for a better readability, see:
Display settings:
Point size 3 px
Line thickness 3 px
Marker size 14 px
Filled markers Yes
Data point is: At the tip of the marker
Fontsize 11 pt
Opacity Reference color 15% -> 50%
Marker settings:
S11 Group delay - Add
page 2: see my screenshot CH0_RG316-50cm_202_500MHz_Open_Group-delay.png
Unfortunately with each sweep the Group Delay varies very much,
between -6 and +8 ps. So, what to take?
The S11 Phase trace was "unwrapped".
page 3: your calculation -1.883 ps * 250 MHz * 360 = -169468
page 5: Here for the Offset Delay a number of -167800 was used,
is that the same value?
I loaded the exported OPEN file nanoVNA_RG174-30cm_202_500MHz_Open.s1p
in Zplots, see screen shot Zplots_page9_RG174-30cm.PNG.
Next step was to click to "Add/Sub".
See screen shot Zplots_page10_RG174-30cm.PNG.
Unfortunately the Length = 30932,2 mm, is x100 of the real length of 309 mm.
At this point I gave up, sorry.
---
Another test was the *comparison* of your file "33cm NanoVNA supplied cable open.s1p" from the archive "Cable measurement.zip" with my own 30 cm RG174 coax cable.
In my measurement of a 30 cm RG174 coax cable, see screen shot nanoVNA-saver_RG174-30cm_Open.png.
I imported your S1P file "33cm NanoVNA supplied cable open.s1p" as a *reference*.
The result is in my screen shot nanoVNA-saver_RG174-30cm_Open_Ref.png.
For me it looks very much the same.
What is you impression?
73, Rudi DL5FA
