Hello Simen, Please let me know the name of the simulation software that you are use. Thanks in advance. Mark Wilkinson ________________________________ From: [email protected] < [email protected]> on behalf of Simen Tobiassen <simen@...> Sent: Friday, March 26, 2021 7:52 AM To: [email protected] < [email protected]> Subject: [nanovna-users] Why does the two currents in a parallel LC-resonance circuit cancel on a lower frequency than the LC-resonance? #coils #charts #test #teaching #traps #simulation #rant #problem #measurement #learning #circuit Simulations show Currents do NOT cancel at the Parallel LC-resonance frequency, contrary to what we learn is one of the main characteristics of parallel resonance circuits. Why? Testing various LC combinations, the two Currents always meet and cancel at a frequency lower than the XL = XC frequency. ? Micro-Cap 12 (Transient Analysis; Oscilloscope) shows LC-resonans frequency / 1.034 ¡Ö frequency of current cancellation. Moving the input frequency up and down from this point you can find the perfect frequency where the two currents have the same amplitude = cancelling. Down in frequency makes the current through the inductor stronger, up makes the current through the capacitor stronger. I mostly use RS = 10m Ohm in both the Capacitor and in the low induction Coil. Same is true with RS = 0 Ohm. LC wise they are perfect(ly fake ;) 0 parasitic L and C. Anyway, the simulation makes no difference; Capacitance added to the inductor gives the same result as if the C was in a separate capacitor; It just moves the LC-resonance to a lower frequency. And the current-cancelling frequency also thereby moves down. This also correlate to the readings on my nanoVNA; two different frequencies, and I do not understand how to combine them into an ¡°official¡± Parallel LC-resonance circuit. -- Simen Tobiassen
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Many simulators apply default series R to L and perhaps C to prevent creating a singularity matrix. In some cases you can over ride the default.
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Re: Saving .s1p, .s2p, and Screenshots Directly from the nanoVNA-H4
Hello i install to a Xtal and now i can see the clock is running in to menu
version...but how i can set the hour and date?
A sexta, 26/03/2021, 13:35, Mario Vano <mvano@...> escreveu:
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I got my crystal from a cheap clock in my junk box that had died from
mechanical problems - the crystal worked great!
M
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If you write the node equations for a parallel LC with an R in series with the L
wo= 1/¡ÌLC ¡Á ¡Ì1-R^2 ¡Á C/L
Yes, the series R will perturb the resonance point from the expected value.
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Thanks, interesting! How is that computed?
But the result however, is the same with Serial Resistance = 0 Ohm in capacitor and in coil; Except I get beats on top of the 888630 Hz waves, probably modulated with the 918881 LC-resonance.
--
Simen Tobiassen
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Re: Saving .s1p, .s2p, and Screenshots Directly from the nanoVNA-H4
I got my crystal from a cheap clock in my junk box that had died from mechanical problems - the crystal worked great!
M
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root (LC) is only true if R=0
If any R is present either in series with L or C, The root (LC) is modified... downward in freq...
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Simulations show Currents do NOT cancel at the Parallel LC-resonance frequency, contrary to what we learn is one of the main characteristics of parallel resonance circuits. Why?
Testing various LC combinations, the two Currents always meet and cancel at a frequency lower than the XL = XC frequency.
?
Micro-Cap 12 (Transient Analysis; Oscilloscope) shows LC-resonans frequency / 1.034 ¡Ö frequency of current cancellation. Moving the input frequency up and down from this point you can find the perfect frequency where the two currents have the same amplitude = cancelling. Down in frequency makes the current through the inductor stronger, up makes the current through the capacitor stronger.
I mostly use RS = 10m Ohm in both the Capacitor and in the low induction Coil. Same is true with RS = 0 Ohm.
LC wise they are perfect(ly fake ;) 0 parasitic L and C. Anyway, the simulation makes no difference; Capacitance added to the inductor gives the same result as if the C was in a separate capacitor; It just moves the LC-resonance to a lower frequency. And the current-cancelling frequency also thereby moves down.
This also correlate to the readings on my nanoVNA; two different frequencies, and I do not understand how to combine them into an ¡°official¡± Parallel LC-resonance circuit.
--
Simen Tobiassen
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Re: Saving .s1p, .s2p, and Screenshots Directly from the nanoVNA-H4
Larry,
Thanks for the info on how to use the SD card. I have not used the time command yet as thought I should install the crystal first.
Ken, NU4I
Sent from my iPod
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On Mar 25, 2021, at 19:42, Larry Rothman <nlroth@...> wrote:
?The 32KHz xtal is only needed if you want a real time of day clock on your unit for accurate dates on data saved to the SD card.
Without the xtal, you'll need to turn on the Nano, set the time using console commands and then use the sdcard.
Many older PC motherboards use the narrow 32KHz xtal and that's where I got mine from for my units. They work fine and old junked motherboards are easy to come by and usually free.
On Thu., 25 Mar. 2021 at 4:02 p.m., Fred, W9KEY<fred.schwierske@...> wrote: So just to clarify - are the new H4 units from R&L Electronics presently shipping with all required hardware to use a (user supplied) microSD card?
1) Or must the above discussed 32KHz crystal first be installed?
2) And do units currently shipping from R&L have cases which include the card slot, or does the user have to cut an access slot?
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Re: Saving .s1p, .s2p, and Screenshots Directly from the nanoVNA-H4
The 32KHz xtal is only needed if you want a real time of day clock on your unit for accurate dates on data saved to the SD card.?
Without the xtal, you'll need to turn on the Nano, set the time using console commands and then use the sdcard.?
Many older PC motherboards use the narrow 32KHz xtal and that's where I got mine from for my units. They work fine and old junked motherboards are easy to come by and usually free.?
On Thu., 25 Mar. 2021 at 4:02 p.m., Fred, W9KEY<fred.schwierske@...> wrote: So just to clarify - are the new H4 units from R&L Electronics presently shipping with all required hardware to use a (user supplied) microSD card?
? 1)? Or must the above discussed 32KHz crystal first be installed?
? 2)? And do units currently shipping from R&L have cases which include the card slot, or does the user have to cut an access slot?
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Re: Pitfalls of measuring components with the NanoVNA
#measurement
So does mine but it still was a clone, nothing major, few resistors where there should be none and some wrong component values. Only way to be sure is to buy from Hugen store. On Thu, 25 Mar 2021 at 19:15, jmr via groups.io <jmrhzu= [email protected]> wrote: It was a long time ago but I did try and buy the Hugen version with the
blue PCB. I just checked and it does say nanoVNA-H v3.3 on the blue PCB and
the case and lettering are the same as the Hugen version. I'm not sure if
the Hugen version is a clone but at the time this seemed to be the one to
buy.
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Re: Saving .s1p, .s2p, and Screenshots Directly from the nanoVNA-H4
I bought my H4 several weeks ago and it did include the microSD card holder attached to the PCB. However, the case did not have a slot cut in it for access. I'll do that myself if I decide to use it.
I don't know anything about the crystal but I don't think it is needed unless you want to have accurate date/time stamps on the files being saved.
--
*Don - W3DRM*
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Re: Saving .s1p, .s2p, and Screenshots Directly from the nanoVNA-H4
So just to clarify - are the new H4 units from R&L Electronics presently shipping with all required hardware to use a (user supplied) microSD card?
1) Or must the above discussed 32KHz crystal first be installed?
2) And do units currently shipping from R&L have cases which include the card slot, or does the user have to cut an access slot?
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Re: Pitfalls of measuring components with the NanoVNA
#measurement
It was a long time ago but I did try and buy the Hugen version with the blue PCB. I just checked and it does say nanoVNA-H v3.3 on the blue PCB and the case and lettering are the same as the Hugen version. I'm not sure if the Hugen version is a clone but at the time this seemed to be the one to buy.
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Re: Pitfalls of measuring components with the NanoVNA
#measurement
AFAIK all open frame versions are clones. I have one that I have updated to the latest version of the schematic, works ok but there were some really weird component values originally. It would not hurt to check yours. On Thu, 25 Mar 2021 at 01:14, jmr via groups.io <jmrhzu= [email protected]> wrote: I'm fairy sure my nanoVNA is an H as it had H firmware on it when it
arrived. It was made in 2019 and is the open frame 2.8" model. At the time
I did try and buy from a proven seller to get a well made example with the
screens and battery fitted.
I didn't keep any notes when I experimented with newer firmware but I
think the newer versions of FW that I struggled with were the Dislord 1038
FW and the (latest?) oneeleven FW. Both of these gave much noisier results
and I do remember trying different bandwidths. I may have missed something
though. I didn't spend much time with either version so maybe I should have
given them a better chance. I found that all of the Edy555 versions of FW
that I tried seemed to give a clean trace on a 100k and a 1R resistor test.
I tried quite a few right up to version 080. However the two most recent
versions 070 and 080 seemed to be prone to freezing up and I think this was
caused by my own PC tools that I use to communicate with the nanoVNA. I
think 070 and 080 have some of Dislord's code in and I'm fairly certain
that both these versions were as good as earlier versions in terms of the
RF performance. It was just the freezing up issue that stops me using these
newer versions. At the moment I'm running 060 FW and this is quite old and
it doesn't have as many features. However, it seems to run reliably with my
PC tools.
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Re: Pitfalls of measuring components with the NanoVNA
#measurement
There are at least two members of this group who are confused about the NanoVNA-H4¡¯s ability to write sp and screenshot files to micro-SD cards and what needs to be done by us to accomplish this ourselves, if in fact it is possible, with the current hardware and firmware. From the various answers we have gotten it seems like some people have been able to do what we are questioning, but the issue is: How did you do it and what, if any mods need to be done to the board? I believe that both of us have been using the latest version of firmware, v1.50, and Rui has plugged the a card into the slot but was not able to get it to be written into. If you have gotten this very useful function to work for you please give us enough information to allow us to do the same. Thanks.
Ken, NU4I
Sent from my iPod
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Show quoted text
On Mar 25, 2021, at 08:58, Jos Stevens <jrs@...> wrote:
?You need the Xtal only when you want to have the date/time displayed correctly.
Jos
Op 25-3-2021 om 09:43 schreef Rui Valente:
Hello
I installed the latest version 1.0.50 and i solder a new SD card
slot...them i tested 3 different sd card and different capacities but
anything happen in the menu sd card (no error message) after i remove the
cards and theyare empty...is necessary install the 32khz cristal ? I don't
install yet...
Thanks in advance...
73 CT2GGX
A quinta, 25/03/2021, 03:59, DiSlord <dislordlive@...> escreveu:
I fix one problem in DSP code (for H version) in 1.0.50.
H4 use DSP instruction and more faster/accurate in calculations
DSP code for H:
do{
int16_t ref = capture[i+0];
int16_t smp = capture[i+1];
int32_t sin = ((int16_t *)sincos_tbl)[i+0];
int32_t cos = ((int16_t *)sincos_tbl)[i+1];
samp_s+= (smp * sin)/16;
samp_c+= (smp * cos)/16;
ref_s += (ref * sin)/16;
ref_c += (ref * cos)/16;
i+=2;
}while (i < length);
Yes /=16 used for prevent overflow on int32 values
Code for H4:
do{
int32_t sc = ((int32_t *)sincos_tbl)[i];
int32_t sr = ((int32_t *)capture)[i];
// int64_t acc DSP functions
acc_samp_s= __smlaltb(acc_samp_s, sr, sc ); // samp_s+= smp * sin
acc_samp_c= __smlaltt(acc_samp_c, sr, sc ); // samp_c+= smp * cos
acc_ref_s = __smlalbb( acc_ref_s, sr, sc ); // ref_s+= ref * sin
acc_ref_c = __smlalbt( acc_ref_c, sr, sc ); // ref_s+= ref * cos
i++;
} while (i < length/2);
It use int64 accumulator (it aslo used for accumulate for
average/bandwidth) and one instruction for calculate (H can`t fast
processing measured data in int64)
On H4 i can get up to - 100 - 110dB dynamic range on measure S21 in 1 to
100MHz
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Re: Pitfalls of measuring components with the NanoVNA
#measurement
You need the Xtal only when you want to have the date/time displayed correctly.
Jos
Op 25-3-2021 om 09:43 schreef Rui Valente:
toggle quoted message
Show quoted text
Hello
I installed the latest version 1.0.50 and i solder a new SD card
slot...them i tested 3 different sd card and different capacities but
anything happen in the menu sd card (no error message) after i remove the
cards and theyare empty...is necessary install the 32khz cristal ? I don't
install yet...
Thanks in advance...
73 CT2GGX
A quinta, 25/03/2021, 03:59, DiSlord <dislordlive@...> escreveu:
I fix one problem in DSP code (for H version) in 1.0.50.
H4 use DSP instruction and more faster/accurate in calculations
DSP code for H:
do{
int16_t ref = capture[i+0];
int16_t smp = capture[i+1];
int32_t sin = ((int16_t *)sincos_tbl)[i+0];
int32_t cos = ((int16_t *)sincos_tbl)[i+1];
samp_s+= (smp * sin)/16;
samp_c+= (smp * cos)/16;
ref_s += (ref * sin)/16;
ref_c += (ref * cos)/16;
i+=2;
}while (i < length);
Yes /=16 used for prevent overflow on int32 values
Code for H4:
do{
int32_t sc = ((int32_t *)sincos_tbl)[i];
int32_t sr = ((int32_t *)capture)[i];
// int64_t acc DSP functions
acc_samp_s= __smlaltb(acc_samp_s, sr, sc ); // samp_s+= smp * sin
acc_samp_c= __smlaltt(acc_samp_c, sr, sc ); // samp_c+= smp * cos
acc_ref_s = __smlalbb( acc_ref_s, sr, sc ); // ref_s+= ref * sin
acc_ref_c = __smlalbt( acc_ref_c, sr, sc ); // ref_s+= ref * cos
i++;
} while (i < length/2);
It use int64 accumulator (it aslo used for accumulate for
average/bandwidth) and one instruction for calculate (H can`t fast
processing measured data in int64)
On H4 i can get up to - 100 - 110dB dynamic range on measure S21 in 1 to
100MHz
|
Re: Pitfalls of measuring components with the NanoVNA
#measurement
Hello
I installed the latest version 1.0.50 and i solder a new SD card
slot...them i tested 3 different sd card and different capacities but
anything happen in the menu sd card (no error message) after i remove the
cards and theyare empty...is necessary install the 32khz cristal ? I don't
install yet...
Thanks in advance...
73 CT2GGX
A quinta, 25/03/2021, 03:59, DiSlord <dislordlive@...> escreveu:
toggle quoted message
Show quoted text
I fix one problem in DSP code (for H version) in 1.0.50.
H4 use DSP instruction and more faster/accurate in calculations
DSP code for H:
do{
int16_t ref = capture[i+0];
int16_t smp = capture[i+1];
int32_t sin = ((int16_t *)sincos_tbl)[i+0];
int32_t cos = ((int16_t *)sincos_tbl)[i+1];
samp_s+= (smp * sin)/16;
samp_c+= (smp * cos)/16;
ref_s += (ref * sin)/16;
ref_c += (ref * cos)/16;
i+=2;
}while (i < length);
Yes /=16 used for prevent overflow on int32 values
Code for H4:
do{
int32_t sc = ((int32_t *)sincos_tbl)[i];
int32_t sr = ((int32_t *)capture)[i];
// int64_t acc DSP functions
acc_samp_s= __smlaltb(acc_samp_s, sr, sc ); // samp_s+= smp * sin
acc_samp_c= __smlaltt(acc_samp_c, sr, sc ); // samp_c+= smp * cos
acc_ref_s = __smlalbb( acc_ref_s, sr, sc ); // ref_s+= ref * sin
acc_ref_c = __smlalbt( acc_ref_c, sr, sc ); // ref_s+= ref * cos
i++;
} while (i < length/2);
It use int64 accumulator (it aslo used for accumulate for
average/bandwidth) and one instruction for calculate (H can`t fast
processing measured data in int64)
On H4 i can get up to - 100 - 110dB dynamic range on measure S21 in 1 to
100MHz
|
Re: MiniVNA vs NanoVNA Balun Test plot query
Arie,
It took me a little while to figure out what a balloon was. I passed the video and tried googling Ballon choke. But then it hit me. The videos are great. They are long but good.
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Re: Pitfalls of measuring components with the NanoVNA
#measurement
I fix one problem in DSP code (for H version) in 1.0.50.
H4 use DSP instruction and more faster/accurate in calculations
DSP code for H:
do{
int16_t ref = capture[i+0];
int16_t smp = capture[i+1];
int32_t sin = ((int16_t *)sincos_tbl)[i+0];
int32_t cos = ((int16_t *)sincos_tbl)[i+1];
samp_s+= (smp * sin)/16;
samp_c+= (smp * cos)/16;
ref_s += (ref * sin)/16;
ref_c += (ref * cos)/16;
i+=2;
}while (i < length);
Yes /=16 used for prevent overflow on int32 values
Code for H4:
do{
int32_t sc = ((int32_t *)sincos_tbl)[i];
int32_t sr = ((int32_t *)capture)[i];
// int64_t acc DSP functions
acc_samp_s= __smlaltb(acc_samp_s, sr, sc ); // samp_s+= smp * sin
acc_samp_c= __smlaltt(acc_samp_c, sr, sc ); // samp_c+= smp * cos
acc_ref_s = __smlalbb( acc_ref_s, sr, sc ); // ref_s+= ref * sin
acc_ref_c = __smlalbt( acc_ref_c, sr, sc ); // ref_s+= ref * cos
i++;
} while (i < length/2);
It use int64 accumulator (it aslo used for accumulate for average/bandwidth) and one instruction for calculate (H can`t fast processing measured data in int64)
On H4 i can get up to - 100 - 110dB dynamic range on measure S21 in 1 to 100MHz
|
W7DRM - Don
Fred, W9KEY