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Firmware Differences

 

I have only downloaded a few firmware updates, but I have noticed a discrepancy. With a calibration from 1MHz to 30MHz and formatted for S11 Smith Chart, the marker position on the Smith chart is correct, but the R+JX is incorrect on versions 1.2.08, 1.2.14 and 1.2.15. However, R+JX is correct on 1.0 and 1.0.71

Tom W0IVJ.
 

Smitch chart marker value must be correct in all versions.

I think you select different smith marker format (Re+Im for example)

Provide screenshot
 

Here are the results of the two different firmware with a 10 ohm resistor attached to the S11 port.
Tom?? W0IVJ

On 10/24/2022 9:42 PM, DiSlord wrote:
Smitch chart marker value must be correct in all versions.

I think you select different smith marker format (Re+Im for example)

Provide screenshot



Version 1.0.71.jpg
Version 1.2.15.jpg

 

On second image Smitch marker format Re Im as i say

Not R+jX as on first (on first values in Om, on second no values)

Change Smitch marker format to R+jX

For select marker format need click on Smitch memu after selecting
 

Here is example:
Trace 1 Smith format: Re Im
Trace 2 Smith format: R + jX
Trace 3 Smith format: R + L/C

Also show Marker format select menu

PS i add this becose R + jX for S11 and S21 different in calculation, last firmware allow multiplie Smith marker traces (as on example) an also allow S21 Serial/Shunt impedance calculation

nanovna-h4_screen_2022-10-25_20-54-16.png
nanovna-h4_screen_2022-10-25_20-54-37.png
nanovna-h4_screen_2022-10-25_20-54-47.png

John N0TA
 

I'm not familiar with the "Re Im" representation -- is this Admittance?
 

DisSlord:
Please draw our attention to the differences between these pictures. I don't see them.
Tell us what to look for in the three traces.

On Tuesday, October 25, 2022, 01:58:08 PM EDT, DiSlord <dislordlive@...> wrote:

Here is example:
Trace 1 Smith format: Re Im
Trace 2 Smith format: R + jX
Trace 3 Smith format: R + L/C

Also show Marker format select menu

PS i add this becose R + jX for S11 and S21 different in calculation, last firmware allow multiplie Smith marker traces (as on example) an also allow S21 Serial/Shunt impedance calculation
 

I'm not familiar with the "Re Im" representation -- is this Admittance?
No. Re Im is the raw complex value of the S11 reflection measurement,
before using mathematical equations to convert it to R and X (or other
values). Admittance is the reciprocal of impedance, represented by Y = G +
jB, where G is conductance an B is susceptance. There are separate
settings on the nano to show these values.

On Tue, Oct 25, 2022, 12:46 PM John N0TA <reillyjf@...> wrote:

I'm not familiar with the "Re Im" representation -- is this Admittance?
 

Thank you.? That is very helpful.

Tom?? W0IVJ

On 10/25/2022 3:23 AM, DiSlord wrote:
On second image Smitch marker format Re Im as i say

Not R+jX as on first (on first values in Om, on second no values)

Change Smitch marker format to R+jX

For select marker format need click on Smitch memu after selecting
 

Thank you.? Now I understand.
Tom? W0IVJ

On 10/25/2022 11:58 AM, DiSlord wrote:
Here is example:
Trace 1 Smith format: Re Im
Trace 2 Smith format: R + jX
Trace 3 Smith format: R + L/C

Also show Marker format select menu

PS i add this becose R + jX for S11 and S21 different in calculation, last firmware allow multiplie Smith marker traces (as on example) an also allow S21 Serial/Shunt impedance calculation
 

Hi All,
I may have missed something here, but these screenshots are not comparing apples to apples.
In the first screenshot the marker is at 1MHz and in the second it is at 30MHz.
Given all the posts in this group about component testing and test fixtures, may I humbly suggest the "error" has more to do with marker frequency than software version.
73...Bob VK2ZRE

On 25/10/2022 8:06 pm, Tom Thompson wrote:
Here are the results of the two different firmware with a 10 ohm resistor attached to the S11 port.
Tom?? W0IVJ

On 10/24/2022 9:42 PM, DiSlord wrote:
Smitch chart marker value must be correct in all versions.

I think you select different smith marker format (Re+Im for example)

Provide screenshot
 

Hi Bob,

The issue was the values appearing on? S11(Smith chart) which DiSlord cleared up nicely.? By? the way, if you have the S11 port terminated in a pure resistance with no transmission line, the frequency makes no difference.? Even though the resistance is other than 50 ohms, the reading will be the same independent of frequency.

Tom?? W0IVJ

On 10/26/2022 7:00 AM, Bob Ecclestone VK2ZRE wrote:
Hi All,
I may have missed something here, but these screenshots are not comparing apples to apples.
In the first screenshot the marker is at 1MHz and in the second it is at 30MHz.
Given all the posts in this group about component testing and test fixtures, may I humbly suggest the "error" has more to do with marker frequency than software version.
73...Bob VK2ZRE


On 25/10/2022 8:06 pm, Tom Thompson wrote:
Here are the results of the two different firmware with a 10 ohm resistor attached to the S11 port.
Tom?? W0IVJ

On 10/24/2022 9:42 PM, DiSlord wrote:
Smitch chart marker value must be correct in all versions.

I think you select different smith marker format (Re+Im for example)

Provide screenshot
 

Hello Tom,

I noticed the format change just after I sent the post:-(
However the frequency difference was what caught my eye and I got "blind sided".
I agree with your comment, however, given other posts on component testing, defining a "pure resistance" is an interesting concept:-)
There was no mention of the test fixture or of resistor type, carbon, metal film or wire wound. A 10 ohm carbon film or wirewound resistor would have a very different response at 30Mhz compared to 1Mhz.
I repaired a piece of kit used to high voltage test sub station power transformers many years ago and it had a Philips 100 ohm 1 watt carbon resistor in series with the vertical input to the integrated CRO in the instrument.
The resistor was fried by a flash over and I was a bit puzzled at first because it was such a low series resistance in what was a high impedance input. I then twigged that it was, in fact, being used as a peaking coil.
Those Philips resistors had the carbon film deposited on the tubular ceramic substrate and then laser etched in a spiral to the required value. Lovely stable inductance!
However, the Smith Chart marker in the post is still on the real axis in both screenshots, negligible +j component. Like said, blind sided:-(

73...Bob VK2ZRE

On 27/10/2022 1:04 am, Tom Thompson W0IVJ wrote:
Hi Bob,

The issue was the values appearing on? S11(Smith chart) which DiSlord cleared up nicely.? By? the way, if you have the S11 port terminated in a pure resistance with no transmission line, the frequency makes no difference.? Even though the resistance is other than 50 ohms, the reading will be the same independent of frequency.

Tom?? W0IVJ

On 10/26/2022 7:00 AM, Bob Ecclestone VK2ZRE wrote:
Hi All,
I may have missed something here, but these screenshots are not comparing apples to apples.
In the first screenshot the marker is at 1MHz and in the second it is at 30MHz.
Given all the posts in this group about component testing and test fixtures, may I humbly suggest the "error" has more to do with marker frequency than software version.
73...Bob VK2ZRE


On 25/10/2022 8:06 pm, Tom Thompson wrote:
Here are the results of the two different firmware with a 10 ohm resistor attached to the S11 port.
Tom?? W0IVJ

On 10/24/2022 9:42 PM, DiSlord wrote:
Smitch chart marker value must be correct in all versions.

I think you select different smith marker format (Re+Im for example)

Provide screenshot
John N0TA
 

This begs the question: Why does the Nano Smith chart default to Re Im, rather than R + jX? It appears to me that Re Im is pretty useless.
- John
 

The chart setting defaults to the value it was set to at the last Save (for
a given slot), so you can set it the way you like.

On Thu, Oct 27, 2022, 7:45 AM John N0TA <reillyjf@...> wrote:

This begs the question: Why does the Nano Smith chart default to Re Im,
rather than R + jX? It appears to me that Re Im is pretty useless.
- John
 

On Thu, Oct 27, 2022 at 07:45 AM, John N0TA wrote:


This begs the question: Why does the Nano Smith chart default to Re Im, rather
than R + jX? It appears to me that Re Im is pretty useless.
- John
Base Smitch diagram value: Re Im


Also Re Im more universal for S11 and S21 some (so i use it as default)
R+jX calculation depend from channel and connect mode (for S21 serial or shunt)
 

Greetings,
Not that I have any real need to know but I am just curious what the "m" abbreviation stands for in the raw data example of "644m + 53.2m"? Does it happen to represent milliVolts RMS, milliVolts PTP calculated from the ADC output measurement values or possibly something else?
--
Best Regards,
Tom, VA7TA
 

Additional:
Re Im - base measured value
All other values calculated from it

NanoVNA traces and formulas.doc
NanoVNA traces and formulas.doc

 

Not that I have any real need to know but I am just curious what the "m" abbreviation stands for in the raw data example of "644m + 53.2m"? Does it happen to represent milliVolts RMS, milliVolts PTP calculated from the ADC output >measurement values or possibly something else?
m - milli
u - micro
M - mega
G - giga
And so on

Re Im value - just complex number
644m + 53.2mj = 0.644 + 0.0532j
 

Many thanks! I now understand it just means "(644/1000) + (53.2/1000)", just as in milliNumber nothing more than that thus the "644m + 53.2m" notation is totally appropriate, IMHO.

--
Thanks Again!
Tom, VA7TA

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