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Is there a manual for the nanovna saver software.

I am trying to take a screen view to email to others for opinions

Neil G3RIR

I have two short cables with alligator clips that I use for looking at baluns, transformers wound on toroids, tuned circuits and what not.

When calibrating should i just tune the the s11 side or should i connect the two together and calibrate to the end of both of them?
Thanks
Bryan

Didn't know that, it's easy uj design a filter from the measured impedance. You need to check the Q or bandwidth and also harmonic suppression.

The first thing to check is if something is amiss in the calibration
process you are using. One common mistake is that you need to reset the
cal before doing a new one. You can also verify the cal before you look at
SWR or other measurements. See the detailed description of calibration and
verification in "The Absolute Beginners Guide" in the files section of this
group, at the following link:
/g/nanovna-users/files/Absolute%20Beginner%20Guide%20to%20The%20NanoVNA/Absolute_Beginner_Guide_NanoVNA_v1_5.pdf


On Fri, Mar 10, 2023, 5:31 PM AJC via groups.io <AGCHURCHJR=
[email protected]> wrote:

I have a VNA SAA-2N. It will not calibrate (it says it does) but with a 50
ohm load the swr is significantly high. (i have tried another set of
standards)

Sorry - looks like I might have transposed some gammas and rhos.

What I ness as by was not reproducible on my non-Greek iPhone:

Here’s what I had in mind for
Gamma = rho angle theta :



Reflection coefficient:
ZL – Z0 Y0 – YL
Γ = ρ∠θ = ----------- = ----------- (6)
ZL + Z0 Y0 + YL

The reflection coefficient gamma represents the quality of the impedance match between the source and the measured load. It is a complex quantity, with magnitude rho and angle theta.

The reflection coefficient is small for good matches. The reflection coefficient takes values from ?1 for shorts, stays negative for loads < Z0, is zero for perfect matches, is positive for loads > Z0, and reaches +1 for open loads.

Using normalized impedances:
窜–1 1–Y Γ = ρ∠θ = ------- = -------
Z+1 1+Y From equ.(5), it follows that s11 is:
窜–1
s11 = ------- = Γ
1+Γ
and Z = -------- (7)
Z+1
Here we see that s11 and Γ (the reflection coefficient) are one and the same.

Thanks for your patience

73
Ed McCann
AG6CX

Regarding an excerpt from your post (perhaps missing a word or two?)

“I use toroidal bifilar wound common mode chokes (CMCs) in my antenna feed
system. I have a 450 set of wires fed with parallel conductor transmission
line. In the shack I install the CMC choke between the open wire line and
the input of my home brew single ended (common mode) L-network for matching
what the antenna/transmission line present in the shack to 50 ± j0 ohms. I
use similar chokes wound on both 31 and 43 ferrite material.”

I’m curious.

Could you provide a bit more detail on your description:


1. The actual antenna in the air.

2. You say to this antenna is connected a “450 set of wires”? Can’t imagine what they would be, unless you were trying to say you feed the aerial with a 450 ohm feedline. Is this correct?

3. If so, is your 450 ohm feed feedline actually measured at 450 ohms? Or is it JSC-1318 or something described as Zo = 450 ohms, but really 400 ohms?

4. A description of your CMC choke at the shack, connected on one side to the parallel feedline and out the other to coax? How many cores? Separate bifilar windings on one or two toroids? Or in series with two different materials #31 and a second with #43?

5. Your observed results of Z CMC offered by each CMC choke ? In form Z=R +jX and related Reflection Coefficient Gamma Vector = rho Angle Gamma? Or dB.

Nice explanation offers to inquiring ham looking for insights!


Looking forward to your response.

73
Ed McCann
AG6CX

I have a VNA SAA-2N. It will not calibrate (it says it does) but with a 50 ohm load the swr is significantly high. (i have tried another set of standards)

On 3/9/23 9:56 PM, Bob Ecclestone VK2ZRE wrote:

G'day Jim,
You are quite right of course.
When I wrote the reply to Don I had only just finished reading his referenced Keysight/Agilent/HP document.
I meant to put in a comment that the document was specifically referring to Metrology grade measurements but my head was still spinning from the degree of detail in the document.
It certainly made extremely interesting reading having spent some time in development labs in past lives.
Connector Savers are a real godsend to the fabulous NanoVNAs and TinySAs currently available to us these days. They are the best accessory you can buy for your instruments.
It is interesting also that HP made a range of Connector Savers and Adapters available and characterised the effect they could/would have on measurements.
Cheers...Bob VK2ZRE

And the cool thing is, with the connector saver, the effects of the saver are incorporated in the calibration. They're so short I doubt there's any interpolation or other issues.

On 3/10/23 10:07 AM, Roger Need via groups.io wrote:

Jim,
Take a look at the NanoVNA groups.io with your browser if you are getting late emails.
Owen Duffy has fixed the interpolation issue in NanoVNA App and it is now working correctly for de-embedding long cables. I made a post on the fix ... /g/nanovna-users/message/31708

I saw that, but didn't realize they were coming in late. I'd get a few, and it just seemed that list traffic was slow.

The result worked out GREAT!

I did an experiment with my (adjustable) 80m antenna. The lowest SWR that I was getting was 1.62:1 at resonance (I can adjust the 80m antenna resonant frequency simply by pulling down on the coax to get the antenna to fold up on itself to raise the resonant frequency, reference my QRZ page for a diagram).

Considering that I have the KAT500 tuner that I can use, it really wasn’t necessary to lower the SWR, but when you use the tuner, there is loss in the coax for the full length of coax to the antenna (minimal though). Also, I don’t have a tuner on my solid-state amp, and I don’t want to push that when I tune too far off resonance, I don’t like to stress it.

On the positive side, with about 75’ of coax to the antenna with a 1.62:1 SWR, that’s only a .02dB SWR loss considering the LMR400 coax, and the total loss is .2dB! Not really worth messing with, really, but I like to experiment.

With the NanoVNA at the output of my external antenna switch (~20’ from the 80m feed point) and turned on the “L/C Match” measurement on the NanoVNA.
The 80m dipole shows:
L/C match for source Z0=50.0(ohms)
Src shunt Series Load shunt
1.6uH 298pF <<< I used this solution
1.1nF 3.4uH

So, I found a coil calculator online:
And found that 10 turns at 1.3” dia. for a length of 2.2” was about 1.6uH.

So, I built a little box with 10 turns on about 1.25” PVC form, and two 560pf 3KV caps in series (6kv, 280pf, close enough).
I mounted it at the same point of the coax as the above measurement (on the output of my antenna switch, going to the antenna).

My LP-100A RF Wattmeter shows an SWR at resonance of 1.01:1.

It’s nice when things work out! I have now 124KHz between the 2:1 SWR points on 80m for my home brew solid state amp.
I’m really getting to like the NanoVNA, it appears very accurate!!!
--
Mike, W0IH

On 3/5/23 3:23 PM, Roger Need via groups.io wrote:

OneOfEleven developed the NanoVNA App for personal use and after moving on to other projects kindly posted it as open source for the community to use and modify. Owen Duffy has created a fork of the OneOfEleven App and corrected some of the errors in the program especially on the info sidebar. I assume that he is reading (but unfortunately not posting) this thread because he has written a 3 part informative blog post on calibration in the NanoVNA App. Readers interested in this topic can use these links:
Part 1 -
Part 2 -
Part 3 -
In his discussion he shows that straight line interpolation can result in worse errors than using Cubic spline interpolation. The latter is used in NanoVNA App. He also states that when operating over a wide frequency band that more scan points is better.
With that in mind I did some more tests using a NanoVNA-H4 in standalone mode and with NanoVNA App OD12 and version 5.4 of NanoVNA Saver.
Calibration conditions
-----------------------------
1. In all cases the SOL was done at the end of 3M of RG-316 coaxial cable fitted with SMA male connectors on both ends. A SMA female was used with a pin header to do the SOL calibration. A 50 ohm 0805 SMD resistor was used as one of the cal loads. See attached photo. Sweep range was 50 kHz. to 900 MHz.
2. The NanoVNA was calibrated on the device using 401 scan points with the default bandwidth setting.
3. NanoVNA Saver was configured to use 401 scan points with 5 averaged sweeps for the calibration.
4. NanoVNA App OD12 was calibrated with 401 and 3201 scan points to see if more scan points made a difference. 8 traces were time averaged and trace smoothing set to 3.
Test Conditions
--------------------
A 75 ohm 0805 SMD resistor was used as the DUT and swept over the 50 kHz. to 900 MHZ. range. Note that interpolation was NOT required/used and scan point frequencies were the same as that done for calibration.
The NanoVNA Saver and NanoVNA Standalone DUT measurements were exported as a Touchstone s1p files and imported into NanoVNA app for comparison. The results are attached.
Observations
------------------
NanoVNA standalone and NanoVNA Saver both gave results that are consistent with what is expected for this DUT. NanoVNA app had a downward trend (for 401 and 3201 scanpoints) after 200 MHz. which is not correct.
Conclusions
----------------
My suspicion is that something is wrong with the implementation of the cubic spline interpolation in NanoVNA App. Perhaps DiSlord or Owen Duffy will consider adding linear interpolation as an option and removing or fixing the cubic spline interpolation.
Roger

A bit of a necro post here (for some reason, lots of groups.io messages are coming through a week late)).


Sweep range was 50 kHz. to 900 MHz. The NanoVNA was calibrated on the device using 401 scan points with the default bandwidth setting.

So the delta F between points is 900/400 or about 2.25 MHz.

This is sufficiently close that phase wraps aren't going to occur with a 3 meter long cable. At 900 MHz, lambda (free space) is .3333 meters. Velocity factor is 0.70 (depends on mfr, but close), so the "in cable" wavelength is 0.23 meters

that 3 meter cable is then 12.857 wavelengths long

At the next lower frequency step, 897.75, lambda is 0.334m, 0.2339m in cable, 12.825 wavelengths in the 3m cable. So the phase of the signal changes about 11.5 degrees.

I'm not sure that the interpolation algorithm cubic vs linear is the problem. It might depend on whether the underlying math is using cartesian (R+jI) or polar (mag, phase). interpolating between two points that are say (1.5 @ 357 degrees) and (1.2 @ 7 degrees) doesn't always come out right, if you're not careful about "going the right direction"

On 3/5/23 9:52 AM, N2MS wrote:

I use my NanoVNA from 0.4 to 150 MHz. I wonder of installing a 10uF coupling capacitor with the 1uF would help the low frequency response. Can anyone recommend a SMD part from Mouser or Digikey?
Thanks,
Mike N2MS

On 03/05/2023 8:22 AM Brian Beezley <k6sti@...> wrote:

I've been looking into the S21 and Y21 methods of calculating an unknown impedance connected between the two VNA ports. The port impedances play a role. I used Micro-Cap to model the NanoVNA-H4 rev 4.3 port networks and calculate their input impedance. I used data sheet values for the semiconductor impedances. Port 1 is on the left in the schematic. Blue/red curves are for port 1 and green/brown are for port 2. Even though the AC-coupling filter corners are only a kHz or two, the phase shift they cause extends much higher. I have seen the effect on measurements at a few hundred kHz.

Brian

Wouldn't that come out in the calibration against presumably flat standards?

Here is a 200 uH homemade plate choke. It was fine fro 160 meter - 40 meter where it was parallel resonate.
Higher than that, no way. A significant number of resonate loops. Quite problematic. This was single layer winding with no attempt to break the windings apart and reduce the parasitic C. The view is crop and hope it is clearer.

G'day Jim,

You are quite right of course.
When I wrote the reply to Don I had only just finished reading his referenced Keysight/Agilent/HP document.
I meant to put in a comment that the document was specifically referring to Metrology grade measurements but my head was still spinning from the degree of detail in the document.
It certainly made extremely interesting reading having spent some time in development labs in past lives.

Connector Savers are a real godsend to the fabulous NanoVNAs and TinySAs currently available to us these days. They are the best accessory you can buy for your instruments.
It is interesting also that HP made a range of Connector Savers and Adapters available and characterised the effect they could/would have on measurements.

Cheers...Bob VK2ZRE

I'm getting emails from last week, just showing up today. How odd.


Looking at the headers

I got it at 19:31 (EST) today (= 0031Z, 10 March)

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Got to Earthlink's mta just now (0031Z on 10 March)

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How very odd...
Is this a groups.io weirdness, or an Earthlink weirdness?

Here is a display for S11 from the vna. Sweep is 1 - 30 MHz, 512 points. A simple SOL cal and then a set of clip leads to the choke.
Choke is standing up right on the tube chassis and the rack panel in place. All is good pass 20 meters... Then things get interesting
as you approach 16 MHz and 21 MHz. Be careful there! A simple mod to the R-175 choke spread the top section of windings
out and moved the self capacitance created so that the resonance that exited was well removed from the HF band. On the
vna easy to see. Not so easy using the GDO. Can be done, just takes time and patience!

Please note. At low frequency as expected the shunt measure of the choke starts at the short side of the chart and rotates CW.
Eventually, parallel resonance occurs. Increase frequency some more and there is where the FUN begins.

On Thu, Mar 9, 2023 at 12:26 PM, Jim VE7RF wrote:

I looked at W8JI's page on plate chokes..... and trying to figure out how he
does the test cables and general setup for testing plate chokes...esp to
arrive at RP values across 160-10m..and also Q,

I see W8JI has a link on his site for testing plate chokes, inductors and traps. Down the page he shows the VNA setup and SOL connections.



Roger

On Thu, Mar 9, 2023 at 10:13 AM, Roy J. Tellason, Sr. wrote:

On Thursday 09 March 2023 10:01:07 am Jim Lux wrote:

One thing that's a bit tricky is that with the usual gold plated
connector, you don't know if it's brass or steel under the plating.

Wouldn't a magnet answer that question?

Answer: it depends, but probably not reliably. Some stainless steels are magnetic and some are not; generally for example 300-series stainless steels are non-magnetic while 400-series are. Asking google "What stainless steel are SMA connectors made of" (admittedly this is lazy person's research) returns that they're made of 303, so they would generally be non-magnetic. However, some stainless steels that are non-magnetic can become locally magnetic where they are cold-worked. For example a typical coin cell battery is made from 304 stainless and if you use a small magnet you'll find that the center of it is not attracted to a magnet but the edge of it, where it has been bent around and crimped to form the seal, is attracted to a magnet.
So in summary, I'd expect this to not be a very reliable method on something as small as an SMA connector that is made from a basically non-magnetic base material.

no .... best is maybe in the nanovna bata tes group (displord modds faster as manufacturer can do a blink)

you maybe will get a unit from the stock and so i is more or less sure that fw is old

....

maybe he want to add his own case with a bigger battery, and sma to n or bnc pigtails or adaptors???

case?? in my view should be metal case

dg9bfc sigi

Am 09.03.2023 um 19:17 schrieb David Rounds:

Yea, there is a corrected version. I biffed it on the Smith Chart - BAD
ENGINEER!!!! That's what I get for not proof reading.....

Dave - W?LEV

--
Dave - W?LEV