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I did a new cal on the H4. It turned out as before, so the old cal was good.

Here are my notes.

H4 phase 1.5 after cal, no cal devices attached. w coax (75 VoP) extension, 1475 ps delay to correct, phase -13.6
After power cycle, phase 1.8 !!
connected coax again, phase -17.0, delay 1460 ps to correct
So...it seems that I need to cycle power after a cal, and then reload the cal. Hmmm...every time I checked, after the first time, the results were close enough.

Saver v0.4.0 - what a mess. Windows 10 x64.
phase1.81 Error during sweep Stopped list index out of bounds
Manage. Don't know how this actually works.
Change to 101 point (H4 is 401), BANDWIDTH to 1000 Hz (H4 is 100)
No error this time, so it seems that Saver doesn't like 401 points. S11 phase -17.14, Saver apparently stops H4 from displaying the sweep, so tapping on screen updates. No. Not always.
Delay -731 ps - no delay applied in H4
Saver left H4 in unstable state, so cycled power
Saver after App
H4 phase -17.1, Saver -17.09
Saver delay -730 ps. as before.
** Note here that Saver is still reporting a delay way off from the H4 and App. And that these values are in the ballpark of what I observer previously, so Saver is consistent. I don't know what I am doing different from you folks, but I sure don't get useful delays. Sure the phase goes to zero, but the delay is way off from the H4 and App.

App v1.1.208 1.783
After power cycle, no delay on H4, phase 1.789
w coax (75 VoP) extension, H4 phase -17.1
App phase -16.84, delay 1463 ps
Disconnected. Closed App. H4 still sweeping.
Checked points, delay, bandwidth...all unchanged, BUT Saver changes those in ways I don't understand yet.
** At one point, App went into a loop on access violation. Needed to kill it. Wouldna shutdown.
Reran Saver. See above.
So at least App is in the same range as the H4. But they should all agree much closer than this. It's all just number crunching. Same numbers, should be same results.

If there is some trick to running Saver, I'm open to suggestions.

On 2022-05-12 15:23:-0700, you wrote:

Finally, NanoVNA Saver versions 2.2 and 4.0 were used with calibration done on NanoVNA itself. The offset delay was done in Saver. S11 phase was flat with - 14.56 nanoseconds required which is the one-way delay and negative in sign.

Summary - Offset delay was equivalent for all cases but required taking half the round trip delay and negating the sign for NanoVNA Saver. One wonders which one of these methods is used in commercial analyzers......

thanks for confirming
~R~

On 2022-05-12 11:57:-0700, you wrote:

H/H4 firmware by default apply internal delay if set and after send it ti CPU. You must reset on device before use Saver software.

Thanks...I was using an existing cal, and was resetting the delay to zero before connecting with the software. It makes sense that the delay will be sent to Saver if Saver uses VNA calibration.

I was puzzled by 2 things
1. The calibration I /thought/ I did a few days ago is actually off by 20 degrees now
2. Saver did not apply the same offset to get the same sweep to 0 phase degrees

I will reset, recal, rerun Saver. Having several ops here report that Saver worked as expected means that I don't have the cal I thought I had.

~R~

On Thu, May 12, 2022 at 08:46 AM, Rich NE1EE wrote:

Just tested -App v 1.1.208
It needed -1750 ps where I expected the same.
It is interesting that I calc the delay based on one way, but the H4 displays
it as round trip.

I attached 3M of RG-316 to a NanoVNA-H4 and used the TDR function to calculate the round-trip delay. It measured 29.5 nanoseconds.

Then the offset delay was adjusted on the NanoVNA until the S11 phase was fairly flat. Offset delay required +29.1 nanoseconds. Screenshot attached.

Next the NanoVNA was connected to NanoVNA app. +29.1 ns offset delay was required in the NanoVNA app program. Measurements were done using calibration the NanoVNA app and with NanoVNA calibration.

Finally, NanoVNA Saver versions 2.2 and 4.0 were used with calibration done on NanoVNA itself. The offset delay was done in Saver. S11 phase was flat with - 14.56 nanoseconds required which is the one-way delay and negative in sign.

Summary - Offset delay was equivalent for all cases but required taking half the round trip delay and negating the sign for NanoVNA Saver. One wonders which one of these methods is used in commercial analyzers......

Tested NanoVNA-H4 with Saver Version 4.

Offset delay works OK - same as version 3.10. Note S11 phase is flat after delay added....

Roger

H/H4 firmware by default apply internal delay if set and after send it ti CPU. You must reset on device before use Saver software.

On 2022-05-12 15:32:+0200, you wrote:

Exactly the same measurements made (from 50 kHz to 50 MHz).
Calibrated with SDR-Kits BNC Cal Kit.
Measurement done with NanoVna -H4 (fw. version 0.5.0) and NanoVna Saver version 0.3.9
Cable used: RG58 A/U

In your image, I see -1540 ps of correction. The value agrees w a VoP of .66 and .305 m of coax.
When do we expect to see a negative angle?
I cal'd with ~175 mm extensions, then when I ran the test this morning, I simply didn't add them. I got a +20deg phase, and needed -1750 to correct. But that seems to imply that you did the same, and I kinda imagined that you slapped a 1ft piece of coax on the calibration plane. When I do the same (add some coax), I get a +phase shift, and the H4 needs +1750 of delay.

Comment?

Just tested -App v 1.1.208
It needed -1750 ps where I expected the same.
It is interesting that I calc the delay based on one way, but the H4 displays it as round trip.

I ran a quick test this morn. Don't have time to investigate, BUT

nVNA-H4 v4.3_MS, firmware 1.1

Saver 0.3.10
Seemed to work better than 0.4, but still puzzling. On -H4, I corrected by -1750ps, as expected. In Saver, +900ps, even though it displayed the same phase angle to begin with.

Saver 0.4.0
Does not connect as reliably as 0.3.10

On both, as I change settings on the H4 and in software, I wind up with index errors, and the only way I can see to get around them is to restart both.
Both applied some correction immediately upon changing Offset Delay.

The important info is that both software versions report a different delay to offset the same phase.
~20deg CCW phase
H4 correction -1750ps
both Saver versions, 900ps

I just tried this again ... and it worked.
The difference? I have no idea.
As a note ... my high end Tek VNA measured the "test awful load" at 57.91+97.35j (|Z|=113.27). The nanoVNA, with applied delay, reported 57.8+93.2j (|Z|=109.67). This is about a 3% difference. I say this is REALLY good.

So ... it looks like we are good to go!

Ralph
WA2PUX
YouTube Channel: Electronics for the Inquisitive Experimenter

/Sorry, no text.

/I happened to have the opportunity to measure the same as Roger did when I read this post.
Exactly the same measurements made (from 50 kHz to 50 MHz).
Calibrated with SDR-Kits BNC Cal Kit.
Measurement done with NanoVna -H4 (fw. version 0.5.0) and NanoVna Saver version 0.3.9
Cable used: RG58 A/U



Op 12-5-2022 om 04:03 schreef Rich NE1EE:

Op 12-5-2022 om 04:03 schreef Rich NE1EE:

I am running the Saver 0.4 version with a nanoVNA V2Plus4 with FW git-20210530-412578c

Ralph
WA2PUX
YouTube Channel: Electronics for the Inquisitive Experimenter

On 2022-05-11 18:20:-0700, you wrote:

I am using NanoVNA Saver 3.10. Offset delay works for me.

I calibrated my NanoVNA-H4 device

Thanks for the update...It might be related to Saver version, because 0.4 is the latest...and it might be related to -H4 firmware version...what are you running?

On Wed, May 11, 2022 at 09:02 AM, Ralph Gable wrote:

However, the Saver software ...
I calibrate as usual.
I set things up to see S11 Phase.
Connect my adapter
Click on Sweep so I have a reference ... where I am starting
Open calibration and enter 500 ps as an offset delay
Click on Apply
Close the Calibration window.
Click on sweep.
The phase does not move ==> the Offset Delay does nothing.
What am I doing wrong?

I am using NanoVNA Saver 3.10. Offset delay works for me.

I calibrated my NanoVNA-H4 device (Not in Saver) from 50 kHz. to 300 MHz. and then attached a 12 inch cable to CH0 (Port 1). You can see the result on the Smith Chart. Then added an offset delay to de-embed for the cable. Smith Chart now shows an open at far right of Smith chart.

Roger

WOW! Seems like a lot of hoops to jump through to use the Saver software
when measuring impedance. The "VNA View" software does it slick as can
be. So, I suppose that the thought is to use the "VNA View" software when
measuring impedances or just the stand alone unit ... at least until they
get that functionality working properly in Saver.
*Ralph*
*WA2PUX*
*YouTube Channel:*
Electronics for the Inquisitive Experimenter


On Wed, May 11, 2022 at 3:28 PM Rich NE1EE <TheDustyKey@...>
wrote:

On 2022-05-11 15:46:+0000, you wrote:

However, the Saver software ...
<Snip>Open calibration and enter 500 ps as an offset delay
<snip>The phase does not move ==> the Offset Delay does nothing.
What am I doing wrong?

Maybe nothing :-) There are some things in Saver that don't work well.
I havna tried this approach, but have applied e-delay on my -H4, and it
works as expected.

I take two approaches to using remote software.
1. Cal the device, including e-delays, and tell the software to use that
cal data, even if I use multiple sweeps.
2. Reset the device, so that there is no cal, then do the cal in software.
It might be that this is the only way the Offset Delay can be applied.
Please try that...and let us know. I assume from the lack of responses that
no one reading so far, I included, know the answer, and I am not set up to
run a test.

~R~

Many thanks for your analysis and comments Roger!

--
Best Regards,
Tom, VA7TA

On 2022-05-11 15:46:+0000, you wrote:

However, the Saver software ...
<Snip>Open calibration and enter 500 ps as an offset delay
<snip>The phase does not move ==> the Offset Delay does nothing.
What am I doing wrong?

Maybe nothing :-) There are some things in Saver that don't work well.
I havna tried this approach, but have applied e-delay on my -H4, and it works as expected.

I take two approaches to using remote software.
1. Cal the device, including e-delays, and tell the software to use that cal data, even if I use multiple sweeps.
2. Reset the device, so that there is no cal, then do the cal in software. It might be that this is the only way the Offset Delay can be applied. Please try that...and let us know. I assume from the lack of responses that no one reading so far, I included, know the answer, and I am not set up to run a test.

~R~

1 - Keeping topics fresh and to the point enhances the groups.io Message Search function.
2 - I lock my group topics after 20 days. (By the end of 10-15 responses, almost every thread gets hijacked to a different topic.
3 - groups.io provides a number of ways to access messages, including digests, emails and online and they do work differently.

Larry
AC9OX

On Tue, May 10, 2022 at 11:36 PM, Maurizio IZ1MDJ wrote:

Hi to all
I note, with disappointment, that many members start new discussions on topics
already covered in previous discussions.
Why not post messages to those threads instead of creating new ones?
In doing so, the usability of the group is compromised.

When a topic has not had any posts for a period of time (months or years) it is better to start a new topic. Posting to the old topic is considered "necroposting" and is discouraged in most groups.


Roger