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Date
Re: The T-Check confusion

 

Kurt,

It appears (in my limited understanding) the poor matching to Z0 of CH1 (port 2) is the biggest reason why the T-check is not performing well on the nanoVNA.
Would you agree that using a 10dB attenuator between DUT and CH1 (port 2) would solve most of this?
What would be the impact of the remaining non-compensated delay?
Should we add to the instructions that, for best nanoVNA 2 port DUT measurements one should seriously consider using a 10dB attenuator between DUT and CH1 (port 2) till new HW becomes available that solves the poor matching of CH1 (port2)?

--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK
Re: Brand new user here

 

Stylus: Guitar pick works also

STX VHF/UHF Rover

On Dec 8, 2019, at 9:49 PM, k9wkj <k9wkjham@...> wrote:

?i use a pen cap or a tooth pick
its a resistive screen so anything pointy and non metalic will work
even a #2 pencil
Re: Brand new user here

Bob Albert
 

I find metallic works well.

On Sunday, December 8, 2019, 07:49:07 PM PST, k9wkj <k9wkjham@...> wrote:

i use a pen cap or a tooth pick
its a resistive screen so anything pointy and non metalic will work
even a #2 pencil
Re: Brand new user here

 

i use a pen cap or a tooth pick
its a resistive screen so anything pointy and non metalic will work
even a #2 pencil
Re: connector swap

 

Photos?



On Sun, 8 Dec 2019 at 1:49 PM, Nulluser00@...<Nulluser00@...> wrote: I mounted my NanoVNA on an Budd aluminim cast box and use male SMA to male SMA to a female SMA to male BNC to bulkhead female to female BNC.
I'm building a RF project gadget box with my
Elecraft XG-1 1/50uV 7.040KHz RF source
Electraft NG-1 RF white noise generator
and other stuff to be added as I go along.
Works great.
Re: 1.5 GHz ??

 

Oh that's useful information. I have some simple measurements to do at 1.2Ghz, will give it a try.

On 12/8/2019 4:34 PM, Bob Albert via Groups.Io wrote:
No configuring necessary.? Simply key in the frequency.
By default it comes up with 900 MHz but you can ask for up to 1.5 GHz and you will get it.
Bob
On Sunday, December 8, 2019, 04:09:55 PM PST, David Eckhardt <davearea51a@...> wrote:
I have read elsewhere than the NANOVNA will operate to1.5 GHz.? Is this
ture?? If so, how do I configure it to do so?
Re: Brand new user here

 

Try your local computer store. I just bought a pack of 10 from Amazon for
less that $& US.
*Clyde K. Spencer*

On Sun, Dec 8, 2019 at 3:52 PM Ray, W4BYG <w4byg@...> wrote:

Clyde,
Thank you. No I don't have a stylus. Not quite sure where to find one.
Ray, W4BYG

On 12/7/2019 10:09 PM, Clyde Spencer wrote:
Have you used a stylus? Fingers are too large for that little screen.
*Clyde K. Spencer*



On Sat, Dec 7, 2019 at 7:53 PM Ray, W4BYG <w4byg@...> wrote:

Just received my new NanoVNA and beginning to learn how to use it. I
have read the "user guide" but it is not much help with my problems:

After I set the menu settings for display, frequency, etc., and start
trying to use it, I am having trouble moving the markers to where I want
them on the trace.

As I go to touch a marker to move it where I want it, the menu comes up
automatically on the right and the marker doesn't move. I close the menu
and try again with the same result. Repeated attempts will eventually
allow me to move the marker, but it is still problematic.

What am I doing wrong or missing?

Also, is there a setting where I can tell it to boot back up to my last
screen settings, instead of the factory default out to 900 MHz? This
would allow saving the battery when I have to be make extended changes
to an antenna and not have to reprogram everything again.

Additionally: Is there software for use with a Win 7 or Win 10 PC and
for Android?

Your assistance would be appreciated.
Ray, W4BYG
Re: nanoVNAPartner v0.17

 

I have this problem also.

On 12/8/2019 8:36 AM, Shmulik Shechter wrote:
i'm not sure i am the first to alert it, but....
somehow the link is blocked by Anti Virus , which states that this site or the file contains " a risk" while the browser tries to reach it.
it might that the site is the problem and not the content , but, is there a way to place it in other location NOT in this site?
--
Cheers, Ed Humphries, KT4ED
Re: The T-Check confusion

 

Hi Herman
First of all it is not the mini-VNA it is the DG8SAQ VNWA.
Sorry these kind of measurements is only possible with a VNA having 10/12 term error correction facilities.
NanoVNA is not able to do such measurements.
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af Herman De Dauw
Sendt: 9. december 2019 00:01
Til: [email protected]
Emne: Re: [nanovna-users] The T-Check confusion

Please, can you not make the PDF with plots of the NanoVNA, and not the Mini-VNA ?
Re: 1.5 GHz ??

Bob Albert
 

No configuring necessary.? Simply key in the frequency.
By default it comes up with 900 MHz but you can ask for up to 1.5 GHz and you will get it.
Bob

On Sunday, December 8, 2019, 04:09:55 PM PST, David Eckhardt <davearea51a@...> wrote:

I have read elsewhere than the NANOVNA will operate to1.5 GHz.? Is this
ture?? If so, how do I configure it to do so?

--

*Dave - W?LEV*
*Just Let Darwin Work*
*Just Think*
1.5 GHz ??

 

I have read elsewhere than the NANOVNA will operate to1.5 GHz. Is this
ture? If so, how do I configure it to do so?

--

*Dave - W?LEV*
*Just Let Darwin Work*
*Just Think*
Re: The T-Check confusion

 

Please, can you not make the PDF with plots of the NanoVNA, and not the Mini-VNA ?
Re: nanoVNAPartner v0.17

 

Not a problem with Windows10 64 bit here.
Re: errors of "error" models

 

Hello again GIN&PEZ

I would like to continuing following your work, but I think you are expecting much mind reading on my part for me to meet that objective. I am able to infer some information from your one port equations and the context of this thread; and I can infer some from the variables used and the general form of several of the equations. As presented however, I am forced to make assumptions that are misleading at best, and incorrect at worst. You need to provide some textual guidance in the form of variable definitions with assignments void of ambiguity, such as the numbers 0 and 1, and the letters O and L. A starting point with a reference baseline set of measurements that are (or will be) required to complete the calculations should be established before the onset of your derivations.

The textual content need not be verbose, but it needs to be clear and unambiguous, precede your equations, and ideally it follows the process regarded as the scientific method.

Is there a message in the timeline listing of the Mathematicians/Philosophers of the Classical and Hellenistic periods; or was this appended to serve as a statement of how you would describe a model of your SOW? :-)

--
73

Gary, N3GO
Re: Brand new user here

Ron Bussiere
 

Here's a 'free' idea that works. Take an old (2 piece) ball point pen and replace the ink tube, with a small diameter piece of wood, sharpened to a point.
Chop stick, wood 'Q tip', (which is what I use), etc.
I have big fingers and this works perfect.
BTW, I always use 'screen protectors' on my VNA, VNA-F, my 7300, 7610, and my new Kenwood TS-890.
I would never recommend a metal stylus of any type.
YMMV and it's your toy.

ron
N4UE
Re: Brand new user here

Bob Albert
 

My 'stylus' is an old metal drafting pencil, the back side, all metal.? It's perfect.
Bob

On Sunday, December 8, 2019, 01:26:30 PM PST, Jim Allyn - N7JA <jim@...> wrote:

On 12/8/19 12:52 PM, Ray, W4BYG wrote:
No I don't have a stylus.? Not quite sure where to find one.

???? The local Dollar Tree has them.? Probably most office supply
stores would have them too.? They are also available on Ebay.
Re: New version of NanoVNA-Saver: 0.2.1

 

Hi Rudi
I insert my comments below

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af reuterr@...
Sendt: 8. december 2019 20:05
Til: [email protected]
Emne: Re: [nanovna-users] New version of NanoVNA-Saver: 0.2.1

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%

Ok about you settings. Still the contras in the PNG files are very poor a dark background like mine blue is much better

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". Group delay is useless for a open dot there is not data to calculate from except noise
<<<<< If you look in my document the phase indicated to -0.1 degree and group delay 24fs and that is still very small values not to trust entirely. See next comment

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?
<<<< You have misunderstood the purpose of this point. First of all you have forgotten to divided by 1e6= 1000000 in my formula which is how to convert a delay to a phaseshift- The -1.883ps leads to -0.169468 degree:
I have made a mistake using a wrong number it should have been -0.98ps which is the fringe C delay for the SMA female adaptor from the female female adaptor terminating the test cable. You calibration is wrong as well as the S11 phase trace has a negative slope with 0.0882 degree at 250MHz as -0.98*250*360/1000000=-0.0882 degree. You will se in my edited document attached it is spot on for my cable. So calibration must be doen with the male kit and offset C is 0.98*20=19.6fF in the calibration settings for NanoVNA-saver.

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.
<<<<Where in the world did you get the figure 30932.2 from ??. You should enter 309mm and fine tune the length until you get a spot in the open position of the Smithchart and also some sensible phase oscillation with tips of the maximums / Minimums on same level.

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?
<<<They should be similar, but while typing this response I cannot got back and look
Kind regards
Kurt

73, Rudi DL5FA

How_to_display_delay_shift_for_a_cable_in_NanoVNA_saver.pdf
How_to_display_delay_shift_for_a_cable_in_NanoVNA_saver.pdf

Re: New version of NanoVNA-Saver: 0.2.1

 

Hi Rudi,

I loaded to Sim Smith Chart your s1p data file. I see some calibrations and/or nanovna errors. The circle not spiral to centre point simmetrically. I subract 31,22cm RG-174 cable from internal model. I have good result to 150 Mhz (blue dot). See attached picture. Currently not have Excel to try zplots. It is my ultra cheap ultra portable laptop only 1024x600 pixel resulution. Sorry for low resolution attachment.

73,
Lajos

rg174.png

Re: Brand new user here

 

On 12/8/19 12:52 PM, Ray, W4BYG wrote:
No I don't have a stylus.? Not quite sure where to find one.

???? The local Dollar Tree has them.? Probably most office supply stores would have them too.? They are also available on Ebay.
Re: Brand new user here

 

Walgreens has stylus - small rubber on one end, take the cap off and you
have a ball point pen.

Dave - W?LEV

On Sun, Dec 8, 2019 at 8:52 PM Ray, W4BYG <w4byg@...> wrote:

Clyde,
Thank you. No I don't have a stylus. Not quite sure where to find one.
Ray, W4BYG

On 12/7/2019 10:09 PM, Clyde Spencer wrote:
Have you used a stylus? Fingers are too large for that little screen.
*Clyde K. Spencer*



On Sat, Dec 7, 2019 at 7:53 PM Ray, W4BYG <w4byg@...> wrote:

Just received my new NanoVNA and beginning to learn how to use it. I
have read the "user guide" but it is not much help with my problems:

After I set the menu settings for display, frequency, etc., and start
trying to use it, I am having trouble moving the markers to where I want
them on the trace.

As I go to touch a marker to move it where I want it, the menu comes up
automatically on the right and the marker doesn't move. I close the menu
and try again with the same result. Repeated attempts will eventually
allow me to move the marker, but it is still problematic.

What am I doing wrong or missing?

Also, is there a setting where I can tell it to boot back up to my last
screen settings, instead of the factory default out to 900 MHz? This
would allow saving the battery when I have to be make extended changes
to an antenna and not have to reprogram everything again.

Additionally: Is there software for use with a Win 7 or Win 10 PC and
for Android?

Your assistance would be appreciated.
Ray, W4BYG







--

*Dave - W?LEV*
*Just Let Darwin Work*
*Just Think*
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