Hi Bryan,
thanks for the Touchstone files - I'll have a look at them, and see if I
can figure out what's going on. :-)
--
Rune / 5Q5R
On Wed, 6 Nov 2019 at 20:21, bryburns via Groups.Io <bryburns=
[email protected]> wrote:
On Wed, Nov 6, 2019 at 01:16 AM, Rune Broberg wrote:
Have you set the NanoVNA to normal (non-TDR) mode before making the
readings?
If you would be willing to send me a Touchstone file of the data, that
would be helpful for testing! :-)
Rune,
Yes, I did set the nanoVNA to non-TDR mode before making the readings.
This is essential to getting good data in nanoVNA-Saver from the nanoVNA.
I recalled cal0 which was created with my best SMA calibrators (from
another VNA) on short male-female connector savers attached directly to the
nanoVNA.
Attached is an S1P file from the ~0.5m long RG316. I also have attached
an S1P file from the ~1 m long 75 ohm cable that you can use for testing
with nanoVNA-Saver 0.1.5. Using the velocity factor for RG316 as 0.695
give a length of 0.56 m for that cable. Setting the velocity factor for the
75 ohm cable to 0.66 yields a cable length of 1.086 m. The cables are
showing a little longer than the measured length because of some 50 ohm
adapters that are about a total of 2" long on the nanoVNA end of the
cables. These are the same cables I used in the nanoVNA screen shots shown
above.
Both cable measurements were made using my best nanoVNA calibration and
the best tuned nanoVNA-Saver calibration.
I hope these help your efforts with the TDR software to show the impedance
vs time.
--
Bryan, WA5VAH
