You say that because you never lived under a military dictatorship.
These political comments (included mine) should be avoided, they are not good for the good health of the group.
Ignacio, EB4APL
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El 26/03/2020 a las 11:31, Dallas KD4HNX via Groups.Io escribi¨®: That's not what my calculator says...
4.2 circuit:91 ohms in parallel with 51+11+51
take 1/91 + 1/113 = 1/x and that comes to 50.4068 ohms...
When I do that to circuit 4.2.1 I come up with 50.64 ohms...
73 Dallas, KD4HNX
Whatever you do, don¡¯t fall victim to?¡°paralysis by
analysis.¡± Go ahead and buy/build one and start
tinkering with it. This is a learn by doing hobby.
No politician or scholar assured your freedoms.
A Soldier, Sailor, Marine, or Airman did!
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Did you do a calculation over the total frequency range or only DC? The impedance mismatch was most prominent at higher frequencies due to SA602 input capacitance. Increasing R22 and R23 reduced this problem. -- NanoVNA Wiki: /g/nanovna-users/wiki/homeNanoVNA Files: /g/nanovna-users/filesErik, PD0EK
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ASSUMING the SA602 inputs are 1.5K each for a total of 3K my calculations come up with changing the 11 ohm 1% resistor with a 13.2 ohm 1% resistor from Digi-Key...??
1 over 1/3000 + 1/91 + 1/115.2 = 49.992 ohms
Only one part needs to be changed vs swapping out all 4...
The 4.2.1 ckt math would be:
1 over?1/3000 + 1/56 + 1/529.9 = 49.806 ohms
73 Dallas, KD4HNX
Whatever you do, don¡¯t fall victim to?¡°paralysis by
analysis.¡± Go ahead and buy/build one and start?
tinkering with it. This is a learn by doing hobby.
No politician or scholar assured your freedoms.
A Soldier, Sailor, Marine, or Airman did!
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Show quoted text
On Thursday, March 26, 2020, 07:58:21 AM EDT, erik@... <erik@...> wrote: 4.2.1 is better because the input impedance of the SA602 (1.5kOhm//3pF per input) has less impact compared to 4.2 -- NanoVNA Wiki: /g/nanovna-users/wiki/homeNanoVNA Files: /g/nanovna-users/filesErik, PD0EK
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Moderated
Re: Another off-topic about Smith chart
I meant "there is not a good subsitute"
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El 26/03/2020 a las 14:00, EB4APL via Groups.Io escribi¨®: If you pay attention, the Smith Chart display on the nanoVNA lacks all units on its axes. This is because this display is intended to see where the impedances are. For measuring, instead of read it on the graph, such in the old times, you use the markers which give you accurate results.
For RF designers used to see the results in a Smith Chart, it is invaluable. You have to learn to interpret it, but here are not a good substitution.
Regards,
Ignacio, EB4APL
El 25/03/2020 a las 20:10, pez@arg escribi¨®:
Smith Chart : In this computer era, this extremely high-effort demanding,
highly-inaccurate, old-time graphics tool became completely obsolete,
because it is a totally useless one in every other aspect except that one
of "just take-a-look demo" - or of fancy impression making to unsuspected,
innocent, inexperienced beginners, of course
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Thank you Helmut and Ignacio for the speedy replies.
Helmut, I am running Windows 10 Home with all recent updates. I had thought about the permissions issue before posting, but was unable to find a place in the install dialog to change the install directory.
Ignacio, Per the documentation for STSW_STM32080, it contains the necessary Windows driver.
At any rate, I think that I resolved my problem. It appears that my system had automatically installed some updates, and was waiting for a reboot to complete the installation. I rebooted my system, after which the DfuSe_Demo installed without any problems.
Thank you again for your inputs.
Jim
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Moderated
Re: Another off-topic about Smith chart
If you pay attention, the Smith Chart display on the nanoVNA lacks all units on its axes. This is because this display is intended to see where the impedances are. For measuring, instead of read it on the graph, such in the old times, you use the markers which give you accurate results.
For RF designers used to see the results in a Smith Chart, it is invaluable. You have to learn to interpret it, but here are not a good substitution.
Regards,
Ignacio, EB4APL
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Show quoted text
El 25/03/2020 a las 20:10, pez@arg escribi¨®: Smith Chart : In this computer era, this extremely high-effort demanding,
highly-inaccurate, old-time graphics tool became completely obsolete,
because it is a totally useless one in every other aspect except that one
of "just take-a-look demo" - or of fancy impression making to unsuspected,
innocent, inexperienced beginners, of course
--
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Moderated
Re: Another off-topic about Smith chart
I am not sure if "reply " is attached to post or thread so..
To Alan Victor ,
OM - would it be possible / appropriate to discuss details of actual C code (OpenGL) implementation in private ?
I am no math wiz, and I am having issues writing the code for imaginary "axis" and I feel the discussion here is heading different direction(s).
BTW your article actually includes "formulas" for drawing the cart, very nice and unexpected benefit. Thanks
73 AA7EJ Vaclav
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Moderated
Re: Another off-topic about Smith chart
On Wed, Mar 25, 2020 at 03:10 PM, pez@arg wrote:
Smith Chart : In this computer era, this extremely high-effort demanding,
highly-inaccurate, old-time graphics tool became completely obsolete,
because it is a totally useless one in every other aspect except that one
of "just take-a-look demo" - or of fancy impression making to unsuspected,
innocent, inexperienced beginners, of course
And like the current and maybe past few generations who grew up doing math on calculators, they can't even add and subtract without them. When the power goes poof, their tools are gone and they're helpless. Use the fancy programs once you learn the basics behind them. And then maybe you can develop a fancy program, too. BruceN / K4TQL -- *"To invent, you need a good imagination and a pile of junk"* -- Thomas Alva Edison (1847-1931)
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Have you the DFU mode driver installed? The normal series port emulator is? used by the Windows programs that communicates the nanoVNA with the PC, such as nanoVNA sarver, but for updating the firmware you need a DFU mode driver that can be downloaded from the same ST website.
I was struck with? DfuSe_Demo until I realized this.
Regards,
Ignacio EB4APL
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El 26/03/2020 a las 2:22, James Bolm escribi¨®: I received a NanoVNA-H, firmware version 0.4.5-1-gfbbceca, Build Time: Dec 26 2019 - 19:32:31 today. Finding that there is new firmware, I read the WIKI and downloaded STSW_STM32080 from the ST website to facilitate the firmware upgrade. When I run DfuSe_Demo_V3.0.6_Setup.exe, it leads me through a few screens to enter my name, and then start the install. It immediately returns a screen with the message that "The wizard was interrupted before DfuSe V3.0.6 could be completely installed. Your system has not been modified. To complete installation at another time, please run setup again." I am running the setup program as an administrator, and have tried running it from the command line, also as administrator, again with no success.
Has anyone else had this problem, and if so, have you found a resolution?
Thank you,
Jim
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I agree...? I'm just saying my calculator says the original circuit is closer...
If I was to change anything I'd swap the 11-ohm resistor with an 8.97-ohm 1% and I'd have a 49.998 impedance...
?
73 Dallas, KD4HNX
Whatever you do, don¡¯t fall victim to?¡°paralysis by
analysis.¡± Go ahead and buy/build one and start?
tinkering with it. This is a learn by doing hobby.
No politician or scholar assured your freedoms.
A Soldier, Sailor, Marine, or Airman did!
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On Thursday, March 26, 2020, 06:42:47 AM EDT, John Baines via Groups.Io <jbaines@...> wrote: These calculated values are correct if, and only if, the actual resistor values are exactly as marked which they will not be. 73 John M0JBA On 26 Mar 2020, at 10:31, Dallas KD4HNX via Groups.Io <mylastname@...> wrote:
That's not what my calculator says...
4.2 circuit:91 ohms in parallel with 51+11+51
take 1/91 + 1/113 = 1/x and that comes to 50.4068 ohms...
When I do that to circuit 4.2.1 I come up with 50.64 ohms...
73 Dallas, KD4HNX
Whatever you do, don¡¯t fall victim to ¡°paralysis by
analysis.¡± Go ahead and buy/build one and start
tinkering with it. This is a learn by doing hobby.
No politician or scholar assured your freedoms.
A Soldier, Sailor, Marine, or Airman did!
? ? On Wednesday, March 25, 2020, 11:30:27 PM EDT, RFy <gpdxdveil@...> wrote:
H4 F303 variant PCB artwork updated to 4.2.1 : Update the schematic diagram, the impedance of ch1 is closer to pure 50 ohms
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These calculated values are correct if, and only if, the actual resistor values are exactly as marked which they will not be.
73
John
M0JBA
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On 26 Mar 2020, at 10:31, Dallas KD4HNX via Groups.Io <mylastname@...> wrote:
That's not what my calculator says...
4.2 circuit:91 ohms in parallel with 51+11+51
take 1/91 + 1/113 = 1/x and that comes to 50.4068 ohms...
When I do that to circuit 4.2.1 I come up with 50.64 ohms...
73 Dallas, KD4HNX
Whatever you do, don¡¯t fall victim to ¡°paralysis by
analysis.¡± Go ahead and buy/build one and start
tinkering with it. This is a learn by doing hobby.
No politician or scholar assured your freedoms.
A Soldier, Sailor, Marine, or Airman did!
On Wednesday, March 25, 2020, 11:30:27 PM EDT, RFy <gpdxdveil@...> wrote:
H4 F303 variant PCB artwork updated to 4.2.1 : Update the schematic diagram, the impedance of ch1 is closer to pure 50 ohms
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That's not what my calculator says...
4.2 circuit:91 ohms in parallel with 51+11+51
take 1/91 + 1/113 = 1/x and that comes to 50.4068 ohms...
When I do that to circuit 4.2.1 I come up with 50.64 ohms...
73 Dallas, KD4HNX
Whatever you do, don¡¯t fall victim to?¡°paralysis by
analysis.¡± Go ahead and buy/build one and start?
tinkering with it. This is a learn by doing hobby.
No politician or scholar assured your freedoms.
A Soldier, Sailor, Marine, or Airman did!
toggle quoted message
Show quoted text
On Wednesday, March 25, 2020, 11:30:27 PM EDT, RFy <gpdxdveil@...> wrote:
H4 F303 variant PCB artwork updated to 4.2.1 : Update the schematic diagram, the impedance of ch1 is closer to pure 50 ohms
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Moderated
Re: Another off-topic about Smith chart
It's just 1/x but flipped and shifted ;)
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Moderated
Re: Another off-topic about Smith chart
"Smith Chart : In this computer era, this extremely high-effort demanding,
highly-inaccurate, old-time graphics tool became completely obsolete,
because it is a totally useless one in every other aspect except that one
of "just take-a-look demo" - or of fancy impression making to unsuspected,
innocent, inexperienced beginners, of course"
Don't know where this idea comes from but it's bollocks. Looking at a smith chart I can instantly get a "feel" of the characteristics of a circuit. There is a reason that when asked to troubleshoot measurements I'll always request to see the smith chart first rather than the logmag plot. I can easily tell apart under-coupled vs over-coupled magnetic loop antennas looking at a smith chart, but they look identical on a logmag plot. Logmag + phase has all the information in theory, but it would take me some minutes of thinking to tell if the magloop is under-coupled or over-coupled. Of course, if I want to know the 10dB bandwidth of the antenna I'll look at logmag instead, there is a time and place for everything.
btw the impedance scale of the middle line on a smith chart is (1+x)/(1-x). It compresses [0, infinity) into [-1, 1]. If you think in terms of reflection coefficient rather than impedance, then the scale of the smith chart is linear and it's nothing more than a polar plot.
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Moderated
Re: Another off-topic about Smith chart
Oooh, si tacuisses ! You try to make believe to be way above it, but: Is that "innocent, unexperienced beginner" perhaps your own point of view? This computer era definitely did not come into existence without many thousands of people that used the Smith Chart. Some people don't have the desire to know more about RF applications than just to watch TV or play games etc. (where others used the Smith Chart for them so they can do that). If that describes you: That's fine: It is your own choice. Just click away. But if you earnestly want to advance in RF design, read on: Obviously you don't know SimSmith: It combines highest design value with comparatively little learning effort, is extremely accurate: both numerically (more accurate digits than you will ever need), graphically highly zoomable, it has a huge number of possible and most useful applications, and is so very flexible, that you even can use it for innovative challenges that perhaps nobody ever did before. It's not perfect, but it is probably the best any Smith Chart user can get. Hans, DJ7BA -----Urspr¨¹ngliche Nachricht----- Von: [email protected] < [email protected]> Im Auftrag von Carey Fisher Gesendet: Donnerstag, 26. M?rz 2020 04:09 An: [email protected]Betreff: Re: [nanovna-users] Another off-topic about Smith chart For people actually designing RF equipment, the Smith Chart is a valuable tool. On Wed, Mar 25, 2020 at 3:10 PM pez@arg <petrosez7@...> wrote: Smith Chart : In this computer era, this extremely high-effort
demanding, highly-inaccurate, old-time graphics tool became completely
obsolete, because it is a totally useless one in every other aspect
except that one of "just take-a-look demo" - or of fancy impression
making to unsuspected, innocent, inexperienced beginners, of course
-- Carey Fisher careyfisher@... -- Diese E-Mail wurde von Avast Antivirus-Software auf Viren gepr¨¹ft.
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On Wed, 25 Mar 2020 18:22:14 -0700, you wrote: I received a NanoVNA-H, firmware version 0.4.5-1-gfbbceca, Build Time: Dec 26 2019 - 19:32:31 today. Finding that there is new firmware, I read the WIKI and downloaded STSW_STM32080 from the ST website to facilitate the firmware upgrade. When I run DfuSe_Demo_V3.0.6_Setup.exe, it leads me through a few screens to enter my name, and then start the install. It immediately returns a screen with the message that "The wizard was interrupted before DfuSe V3.0.6 could be completely installed. Your system has not been modified. To complete installation at another time, please run setup again." I am running the setup program as an administrator, and have tried running it from the command line, also as administrator, again with no success.
Has anyone else had this problem, and if so, have you found a resolution?
Thank you,
Jim
What operating system? WIN10 (and WIN7) protects some folders against modifications. Create a directory in the root and name it as you wish, e.g. as C:\MyName and do the install there. w.
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H4 F303 variant PCB artwork updated to 4.2.1 : Update the schematic diagram, the impedance of ch1 is closer to pure 50 ohms
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Moderated
Re: Another off-topic about Smith chart
For people actually designing RF equipment, the Smith Chart is a valuable
tool.
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Show quoted text
On Wed, Mar 25, 2020 at 3:10 PM pez@arg <petrosez7@...> wrote: Smith Chart : In this computer era, this extremely high-effort demanding,
highly-inaccurate, old-time graphics tool became completely obsolete,
because it is a totally useless one in every other aspect except that one
of "just take-a-look demo" - or of fancy impression making to unsuspected,
innocent, inexperienced beginners, of course
--
Carey Fisher
careyfisher@...
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I received a NanoVNA-H, firmware version 0.4.5-1-gfbbceca, Build Time: Dec 26 2019 - 19:32:31 today. Finding that there is new firmware, I read the WIKI and downloaded STSW_STM32080 from the ST website to facilitate the firmware upgrade. When I run DfuSe_Demo_V3.0.6_Setup.exe, it leads me through a few screens to enter my name, and then start the install. It immediately returns a screen with the message that "The wizard was interrupted before DfuSe V3.0.6 could be completely installed. Your system has not been modified. To complete installation at another time, please run setup again." I am running the setup program as an administrator, and have tried running it from the command line, also as administrator, again with no success.
Has anyone else had this problem, and if so, have you found a resolution?
Thank you,
Jim
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Dallas N4DDM
James Bolm
OwO
