Re: nanovna-saver crashes with H4
I forgot to mention that the nano 2.8 hardware is on some old software. My
H4 software is also old 1.0.64. It was installed May 31 2021
Fred
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On Mon, Jun 26, 2023 at 5:19?PM Tim Dawson <tadawson@...> wrote: What code version(s) are on the NanoVNA's?
On Mon, June 26, 2023 5:06 pm, Fred Moore wrote:
I am confused. A friend of mine and I are trying to figure out why *my
nano H4 and his very early nano vna with the 2.8" screen will both run on
his nano saver 0.3.7.* His 2.8 nano runs on my computer on saver 0.3.8
but mine does not. My w10 system complains about
*Error during sweep*
*Stopped*
*Failed to read data 1 10 times*
*Data outside expected valid ranges, or in unexpected format.*
*You can disable validation on the device settings screen.*
This just happened in the last couple of days. I have both 0.3.7 and
0.3.8
on my W10 system and this problem exists on both saver versions.
Help
Fred - N4CLA
On Thu, Dec 17, 2020 at 9:00?€?AM GM4OSS <stevegm4oss@...> wrote:
Hi
I'm new to this group and just received a nanovna H4. When I launch
nano saver V 0.3.80 on (W10 PC) it sees the H4 (Com 5) and after I
click 'Connect to Device' the software crashes.
I did notice from the nano-saver.exe the following message before
crashing. 'Did not recognise nanovna device from firmware'.
Help please - is there a work around?
--
73 de Steve GM4OSS
--
Tim Dawson (tadawson@...) Owner/Engineer
TPC Services Bellnet: (906)-482-5732
Houghton, MI 49931
"The world is complex. Sendmail.cf reflects this...."
|
Re: nanovna-saver crashes with H4
My Nano H4 is on a DiSlord version 1.0.64
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On Mon, Jun 26, 2023 at 5:19?PM Tim Dawson <tadawson@...> wrote: What code version(s) are on the NanoVNA's?
On Mon, June 26, 2023 5:06 pm, Fred Moore wrote:
I am confused. A friend of mine and I are trying to figure out why *my
nano H4 and his very early nano vna with the 2.8" screen will both run on
his nano saver 0.3.7.* His 2.8 nano runs on my computer on saver 0.3.8
but mine does not. My w10 system complains about
*Error during sweep*
*Stopped*
*Failed to read data 1 10 times*
*Data outside expected valid ranges, or in unexpected format.*
*You can disable validation on the device settings screen.*
This just happened in the last couple of days. I have both 0.3.7 and
0.3.8
on my W10 system and this problem exists on both saver versions.
Help
Fred - N4CLA
On Thu, Dec 17, 2020 at 9:00?€?AM GM4OSS <stevegm4oss@...> wrote:
Hi
I'm new to this group and just received a nanovna H4. When I launch
nano saver V 0.3.80 on (W10 PC) it sees the H4 (Com 5) and after I
click 'Connect to Device' the software crashes.
I did notice from the nano-saver.exe the following message before
crashing. 'Did not recognise nanovna device from firmware'.
Help please - is there a work around?
--
73 de Steve GM4OSS
--
Tim Dawson (tadawson@...) Owner/Engineer
TPC Services Bellnet: (906)-482-5732
Houghton, MI 49931
"The world is complex. Sendmail.cf reflects this...."
|
On Mon, Jun 26, 2023 at 05:25 PM, Roger Need wrote: Calibrating with the crocodile clips will not give you a good reference plane.
The reason I say this is if you keep them the same distance apart when you
cal with an open, short and load you will have considerable inductance in the
short and 50 ohm "cal loads". If you calibrate with the clips close together
and then spread them the reference plane has changed. Neither is a good
option.
I suggest you calibrate right at the screw terminations on the green block
with the alligator clip leads removed. Then attach the leads and make your
measurement. From the photo it looks like the leads are about 4" long and
each one will add about 100 nH of inductance (total 200 nH or 0.2 uH). That
extra .2 uH when you are measuring 110 uH is not significant. However you
should get a better estimate of the SRF and be able to calculate the parasitic
capacitance to more accuracy.
Try it and see what you find...
Roger
Thanks Roger, I will try that tomorrow. -- Mike
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Re: nanovna-saver crashes with H4
What code version(s) are on the NanoVNA's?
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On Mon, June 26, 2023 5:06 pm, Fred Moore wrote: I am confused. A friend of mine and I are trying to figure out why *my
nano H4 and his very early nano vna with the 2.8" screen will both run on
his nano saver 0.3.7.* His 2.8 nano runs on my computer on saver 0.3.8
but mine does not. My w10 system complains about
*Error during sweep*
*Stopped*
*Failed to read data 1 10 times*
*Data outside expected valid ranges, or in unexpected format.*
*You can disable validation on the device settings screen.*
This just happened in the last couple of days. I have both 0.3.7 and
0.3.8
on my W10 system and this problem exists on both saver versions.
Help
Fred - N4CLA
On Thu, Dec 17, 2020 at 9:00?€?AM GM4OSS <stevegm4oss@...> wrote:
Hi
I'm new to this group and just received a nanovna H4. When I launch
nano saver V 0.3.80 on (W10 PC) it sees the H4 (Com 5) and after I
click 'Connect to Device' the software crashes.
I did notice from the nano-saver.exe the following message before
crashing. 'Did not recognise nanovna device from firmware'.
Help please - is there a work around?
--
73 de Steve GM4OSS
--
Tim Dawson (tadawson@...) Owner/Engineer
TPC Services Bellnet: (906)-482-5732
Houghton, MI 49931
"The world is complex. Sendmail.cf reflects this...."
|
Re: nanovna-saver crashes with H4
I am confused. A friend of mine and I are trying to figure out why *my
nano H4 and his very early nano vna with the 2.8" screen will both run on
his nano saver 0.3.7.* His 2.8 nano runs on my computer on saver 0.3.8 but
mine does not. My w10 system complains about
*Error during sweep*
*Stopped*
*Failed to read data 1 10 times*
*Data outside expected valid ranges, or in unexpected format.*
*You can disable validation on the device settings screen.*
This just happened in the last couple of days. I have both 0.3.7 and 0.3.8
on my W10 system and this problem exists on both saver versions.
Help
Fred - N4CLA
toggle quoted message
Show quoted text
On Thu, Dec 17, 2020 at 9:00?AM GM4OSS <stevegm4oss@...> wrote: Hi
I'm new to this group and just received a nanovna H4. When I launch nano
saver V 0.3.80 on (W10 PC) it sees the H4 (Com 5) and after I click
'Connect to Device' the software crashes.
I did notice from the nano-saver.exe the following message before crashing.
'Did not recognise nanovna device from firmware'.
Help please - is there a work around?
--
73 de Steve GM4OSS
|
On 6/26/23 11:12 AM, Fran?ois wrote: It's possible, that with some active systems, you could get a reflection
that is bigger than the incident wave (i.e. if the Zload were negative).
But I think that for an entirely passive load, the reflected wave
cannot be greater than the incident wave. We have a little trouble understanding each other. It is not a question of measurement but of calculation.
I have an adapter which for a given input impedance returns the impedance
Zout = 1.96593624236642 -j 5601.37911926951)}
The impedance I'm targeting is
Ztarget = 50 +j 100
the results are recalculated in the Excel sheet attached
S11 = 1.03617959022359 -j 0.0185190120640808
SWR = -56.028101163433028 negative
|S11| = 1.036345067 -> |S11| > 1
Indeed.. For instance if Z1 = 2 - 1000j and Z2 is 50 + 100j, then gamma = (Z1-Z2)/(Z1+Z2) gamma = 1.215 - 0.124j |gamma| > 1 (and it's not some sort of numerical precision thing) OK, we must have some interpretation problem. And it's not obviously "unphysical" - I can see a source with Z 50 + 100 j (A series inductor) and a load of 2-1000j (a series capacitor). Sure, it's not a conjugate match, but obviously power will be dissipated in the 50 ohm resistor. So this must be a case where "reflection coefficient" as defined by impedances isn't correct. There's no real transmission line here, so I'm not sure that the concept of a "traveling wave" (where gamma is reflected/incident) is valid.
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Re: Outliers in group delay measurement
Here it is, thanks for taking a minute to look into it.
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Re: Outliers in group delay measurement
Or is the best path forward just to
remove the outliers manually when processing the data. can you send as attachment your .s2p file I wrote a little software to smooth out the errors. I would see what happens. -- F1AMM Fran?ois De la part de astech119 Envoy¨¦ : lundi 26 juin 2023 18:32
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It's possible, that with some active systems, you could get a reflection
that is bigger than the incident wave (i.e. if the Zload were negative).
But I think that for an entirely passive load, the reflected wave
cannot be greater than the incident wave. We have a little trouble understanding each other. It is not a question of measurement but of calculation. I have an adapter which for a given input impedance returns the impedance Zout = 1.96593624236642 -j 5601.37911926951)} The impedance I'm targeting is Ztarget = 50 +j 100 the results are recalculated in the Excel sheet attached S11 = 1.03617959022359 -j 0.0185190120640808 SWR = -56.028101163433028 negative |S11| = 1.036345067 -> |S11| > 1 -- F1AMM Fran?ois De la part de Jim Lux lundi 26 juin 2023 16:58
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Outliers in group delay measurement
I'm measuring the group delay of some 60in cables with a NanoVNAH4 and I am getting outliers in the data. I am using nano-vna saver and I have tried both with on board calibration disabled and calibrated from 50kHz to 1.5GHz, the outliers are present still. I also have another H4 and I had the same issue just at a lower frequency ~150MHz. In the attached plot the points go to about +- 20 ns at just under 700MHz. I have also changed the sweep to have a lower df width but the same outliers were there at the same frequency. My sweep here is 1Mhz to 701Mhz 1212 pts 3avg df=578kHz
Is there any explanation or way to minimize this? Or is the best path forward just to remove the outliers manually when processing the data.
Thanks!
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On Mon, Jun 26, 2023 at 01:23 AM, Mike wrote:
This is my test fixture, calibrated at the croc clips. It's not ideal but I'm
limited by the length of the coil. Should be OK at my measurement frequency of
70kHz though!
Calibrating with the crocodile clips will not give you a good reference plane. The reason I say this is if you keep them the same distance apart when you cal with an open, short and load you will have considerable inductance in the short and 50 ohm "cal loads". If you calibrate with the clips close together and then spread them the reference plane has changed. Neither is a good option. I suggest you calibrate right at the screw terminations on the green block with the alligator clip leads removed. Then attach the leads and make your measurement. From the photo it looks like the leads are about 4" long and each one will add about 100 nH of inductance (total 200 nH or 0.2 uH). That extra .2 uH when you are measuring 110 uH is not significant. However you should get a better estimate of the SRF and be able to calculate the parasitic capacitance to more accuracy. Try it and see what you find... Roger
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On 6/26/23 7:26 AM, Fran?ois wrote: I knew about the phone lines. My problem is that if we calculate the S11 with complex values, it leads, for example, to a ROS which can be negative. S11 is no longer in a circle of radius 1.
Is this normal or am I mistaken? It's possible, that with some active systems, you could get a reflection that is bigger than the incident wave (i.e. if the Zload were negative). But I think that for an entirely passive load, the reflected wave cannot be greater than the incident wave.
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My study (amateur) concerns the cascading of 2 adapters in 'L' one high pass and the other low pass to carry out two adaptations of impedance at two different frequencies.
To generalize the brought back impedance can be different for the two frequencies and complex.
It works easily with a purely real impedance but when the impedance is complex, I tried to optimize the ROS by looking for its minimum value which I thought was ONE it does not work because the ROS varies from - infinity to + infinity.
I had to change the search criteria to subtraction
double optimizer = Complex.Subtract(Zouth_, Application.Zcibleh).Magnitude;
And now it works. What is curious is that when the solution adapter is found, the ROS is indeed equal to ONE. A crazy story.
--
F1AMM
Fran?ois
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I knew about the phone lines. My problem is that if we calculate the S11 with complex values, it leads, for example, to a ROS which can be negative. S11 is no longer in a circle of radius 1.
Is this normal or am I mistaken?
--
F1AMM
Fran?ois
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-----Message d'origine----- De la part de Maynard Wright, P. E., W6PAP Envoy¨¦ : lundi 26 juin 2023 16:21
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On 6/26/23 06:32, Jim Lux wrote: On 6/26/23 2:22 AM, Fran?ois wrote:
Hello
In the attached formula (ROS.png), as long as Zo is real, even if Zl is complex, everything is fine and S11 remains in a circle of radius 1. and the ROS is between 1 and infinity.
If Zo is complex, this is no longer the case.
While writing C# code looking for a (complex) adaptation by dichotomy, I was looking for a ROS of 1. It doesn't work. I had to use the modulus of the difference between my target and the current value.
double optimiseur = Complex.Subtract(Zouth_, Application.Zcibleh).Magnitude;
Is it legitimate to talk about S11 when Zo is complex?
73 Sure it is: S11 is just a representation of the reflection coefficient on port 1 of the UUT.? Generally people use just the log magnitude in dB, but it has a phase, too.
Nothing prevents the Z0 being complex.
Definitely so. When working with telephone cable pairs at voice frequencies, Zo is always complex, generally with a phase angle approaching -45 degrees. Various graphical aids were published by the Bell System for solving transmission line problems with complex Zo, but today it's more common to simply solve the appropriate expressions using complex math in software. Various schemes were developed for "loading" cable pairs for voice transmission, the most common being the addition of inductors at intervals of a few thousand feet. The most common loading scheme in the Bell System added 88 mH every 6000 feet, but there were quite a few other loading schemes in use. Loading a pair made it's Zo close to, but not exactly, real across the frequency span of the load scheme, reduced the loss of the pair within that frequency span, and acted as a sharp cutoff low-pass filter, reducing significantly transmission at frequencies above the cutoff frequency. 73, Maynard W6PAP
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On 6/26/23 2:22 AM, Fran?ois wrote: Hello
In the attached formula (ROS.png), as long as Zo is real, even if Zl is complex, everything is fine and S11 remains in a circle of radius 1. and the ROS is between 1 and infinity.
If Zo is complex, this is no longer the case.
While writing C# code looking for a (complex) adaptation by dichotomy, I was looking for a ROS of 1. It doesn't work. I had to use the modulus of the difference between my target and the current value.
double optimiseur = Complex.Subtract(Zouth_, Application.Zcibleh).Magnitude;
Is it legitimate to talk about S11 when Zo is complex?
73 Sure it is: S11 is just a representation of the reflection coefficient on port 1 of the UUT. Generally people use just the log magnitude in dB, but it has a phase, too. Nothing prevents the Z0 being complex.
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Hello
In the attached formula (ROS.png), as long as Zo is real, even if Zl is complex, everything is fine and S11 remains in a circle of radius 1. and the ROS is between 1 and infinity.
If Zo is complex, this is no longer the case.
While writing C# code looking for a (complex) adaptation by dichotomy, I was looking for a ROS of 1. It doesn't work. I had to use the modulus of the difference between my target and the current value.
double optimiseur = Complex.Subtract(Zouth_, Application.Zcibleh).Magnitude;
Is it legitimate to talk about S11 when Zo is complex?
73
--
F1AMM
Fran?ois
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This is my test fixture, calibrated at the croc clips. It's not ideal but I'm limited by the length of the coil. Should be OK at my measurement frequency of 70kHz though!
--
Mike
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Hey guys,
I have NO affiliation with this company but Battery Hookup has absolutely the best prices when it comes to the 18650 lipo cells. They also have flat cells with power levels of 4.5Ahr @ 3.7v
Mike C. Sand Mtn GA
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On 6/25/2023 9:51 AM, Michael wrote: Thanks for all the help
I do have the smaller original VNA-H model
It does have a rechargeable battery. I charged it up and the unit turns on and there is software in it.
I'll purchase some SMA adapters to able to connect it to antennas.
I was watching videos on the wrong models and got confused.
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On Sun, Jun 25, 2023 at 03:15 PM, Roger Need wrote:
The VNA can only measure R + jX or R//jX (with later firmware versions). It
calculates inductance by dividing X by 2*pi*frequency and this ONLY gives an
estimate of the true coil L if the coil is air wound and the frequency is low
enough that the skin effect is not having much effect on underlying
inductance.
Roger, the method I suggested requires inductance calculated this way. It yields an accurate coil model over a narrow frequency range. To my surprise, it seemed good enough over the whole 3.5-4 MHz band. But the wideband model suggested in the writeup noticeably improved accuracy over the somewhat wider 88-108 MHz band. Brian
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Roger Need
Mike C.