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On Sun, Jan 26, 2020 at 01:29 PM, Oristo wrote:
OK, since you ask, but I find yours much simpler to follow
==================================================
Kind of you to say Oristo. The comments that followed my post, regarding my mixing up the wavelength terms, were right and require correcting. Andy's explanation is easy to understand. My steps are easy for me to remember and have worked every time, but now I have added Andy's explanation to them in my notebook.
Best regards,
- Herb
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Ah now I have found it, or eureka!? The trick is not to measure at the eighth wave (6 o'clock) point of the Smith chart; I was doing that and getting precisely 50 Ohms no matter what.
The trick is to go to the quarter wave (9 o'clock) point as precisely as possible, then measure the capacitance at half that frequency.? The reactance is the numerical value of characteristic impedance.
My version of firmware doesn't support a Reactance menu item (I use Phase instead) so I have to measure capacitance and then the formula 1/(2*pi*f*C).? My scientific calculator does it almost instantly.
When I did that with various cables, I see that none are exactly nominal Z, but plenty close enough, within an Ohm or three.? Much more believable than what I was getting.
Thanks to all who submitted comments and ideas.
Bob
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On Sunday, January 26, 2020, 02:09:58 PM PST, hwalker <herbwalker2476@...> wrote:
On Sun, Jan 26, 2020 at 01:29 PM, Oristo wrote:
OK, since you ask, but I find yours much simpler to follow
==================================================
Kind of you to say Oristo.? The comments that followed my post, regarding my mixing up the wavelength terms, were right and require correcting.? Andy's explanation is easy to understand.? My steps are easy for me to remember and have worked every time, but now I have added Andy's explanation to them in my notebook.
Best regards,
- Herb
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Hi The nanoVNA partner does it semi automatic with a smart feature and a couple of mouse clicks Use nanoVNA Partner v0.20 link: Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] < [email protected]> P? vegne af Bob Albert via Groups.Io Sendt: 27. januar 2020 00:39 Til: [email protected]Emne: Re: [nanovna-users] characteristic impedance Ah now I have found it, or eureka! The trick is not to measure at the eighth wave (6 o'clock) point of the Smith chart; I was doing that and getting precisely 50 Ohms no matter what. The trick is to go to the quarter wave (9 o'clock) point as precisely as possible, then measure the capacitance at half that frequency. The reactance is the numerical value of characteristic impedance. My version of firmware doesn't support a Reactance menu item (I use Phase instead) so I have to measure capacitance and then the formula 1/(2*pi*f*C). My scientific calculator does it almost instantly. When I did that with various cables, I see that none are exactly nominal Z, but plenty close enough, within an Ohm or three. Much more believable than what I was getting. Thanks to all who submitted comments and ideas. Bob
On Sunday, January 26, 2020, 02:09:58 PM PST, hwalker <herbwalker2476@...> wrote:
On Sun, Jan 26, 2020 at 01:29 PM, Oristo wrote:
OK, since you ask, but I find yours much simpler to follow ==================================================
Kind of you to say Oristo. The comments that followed my post, regarding my mixing up the wavelength terms, were right and require correcting. Andy's explanation is easy to understand. My steps are easy for me to remember and have worked every time, but now I have added Andy's explanation to them in my notebook.
Best regards,
- Herb
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Kurt, I went there and downloaded the file but am told it's corrupted.
Bob
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On Sunday, January 26, 2020, 04:37:51 PM PST, Kurt Poulsen <kurt@...> wrote: Hi The nanoVNA partner does it semi automatic with a smart feature and a couple of mouse clicks Use nanoVNA Partner v0.20? link: Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] < [email protected]> P? vegne af Bob Albert via Groups.Io Sendt: 27. januar 2020 00:39 Til: [email protected]Emne: Re: [nanovna-users] characteristic impedance Ah now I have found it, or eureka!? The trick is not to measure at the eighth wave (6 o'clock) point of the Smith chart; I was doing that and getting precisely 50 Ohms no matter what. The trick is to go to the quarter wave (9 o'clock) point as precisely as possible, then measure the capacitance at half that frequency.? The reactance is the numerical value of characteristic impedance. My version of firmware doesn't support a Reactance menu item (I use Phase instead) so I have to measure capacitance and then the formula 1/(2*pi*f*C).? My scientific calculator does it almost instantly. When I did that with various cables, I see that none are exactly nominal Z, but plenty close enough, within an Ohm or three.? Much more believable than what I was getting. Thanks to all who submitted comments and ideas. Bob ? ? On Sunday, January 26, 2020, 02:09:58 PM PST, hwalker <herbwalker2476@...> wrote: On Sun, Jan 26, 2020 at 01:29 PM, Oristo wrote: OK, since you ask, but I find yours much simpler to follow ================================================== Kind of you to say Oristo.? The comments that followed my post, regarding my mixing up the wavelength terms, were right and require correcting.? Andy's explanation is easy to understand.? My steps are easy for me to remember and have worked every time, but now I have added Andy's explanation to them in my notebook. Best regards, - Herb
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I have a bit more information.? I have a cable going to a coaxial switch that shorts unused connectors.? So the cable, unless I select it, has a short at the end.
The procedure, with slight modification, works as well for a short at the end.
Instead of a circle starting at the right and sweeping down and around to the left edge, it starts at the left and sweeps up and around to the right edge.? When you take half the frequency of its intersection at the right edge and use that for CW stimulus, the screen shows inductance instead of capacitance.? So instead of the capacitive reactance calculation you do the inductance, where X = 2*pi*f*L and get the answer.
I learn about electronics and, specifically, transmission lines every day.
Bob K6DDX
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On Sunday, January 26, 2020, 04:37:51 PM PST, Kurt Poulsen <kurt@...> wrote: Hi The nanoVNA partner does it semi automatic with a smart feature and a couple of mouse clicks Use nanoVNA Partner v0.20? link: Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] < [email protected]> P? vegne af Bob Albert via Groups.Io Sendt: 27. januar 2020 00:39 Til: [email protected]Emne: Re: [nanovna-users] characteristic impedance Ah now I have found it, or eureka!? The trick is not to measure at the eighth wave (6 o'clock) point of the Smith chart; I was doing that and getting precisely 50 Ohms no matter what. The trick is to go to the quarter wave (9 o'clock) point as precisely as possible, then measure the capacitance at half that frequency.? The reactance is the numerical value of characteristic impedance. My version of firmware doesn't support a Reactance menu item (I use Phase instead) so I have to measure capacitance and then the formula 1/(2*pi*f*C).? My scientific calculator does it almost instantly. When I did that with various cables, I see that none are exactly nominal Z, but plenty close enough, within an Ohm or three.? Much more believable than what I was getting. Thanks to all who submitted comments and ideas. Bob ? ? On Sunday, January 26, 2020, 02:09:58 PM PST, hwalker <herbwalker2476@...> wrote: On Sun, Jan 26, 2020 at 01:29 PM, Oristo wrote: OK, since you ask, but I find yours much simpler to follow ================================================== Kind of you to say Oristo.? The comments that followed my post, regarding my mixing up the wavelength terms, were right and require correcting.? Andy's explanation is easy to understand.? My steps are easy for me to remember and have worked every time, but now I have added Andy's explanation to them in my notebook. Best regards, - Herb
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On Mon, Jan 27, 2020 at 01:37 AM, Kurt Poulsen wrote:
The nanoVNA partner does it semi automatic with a smart feature and a couple
of mouse clicks
Use nanoVNA Partner v0.20 link:
Hello Kurt, Do you please have an example for measuring coax impedance with nanoVNA partner version 0.20 ? Unfortunately neb40gsm does not provide any help info. Attached is: nanoVNApartner0.20_Impedance_RG316-50cm.PNG screenshot nanoVNApartner0.20_Impedance_RG316-50cm.s1p S1P file 73, Rudi DL5FA
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Bob Albert
2:43am #10292
Kurt, I went there and downloaded the file but am told it's corrupted.
Bob
Hi Bob, Please download from: neb sent it to me for testing, which I gladly did. Since I didn't get a detailed description, there are a few things I had to figure out ... but it still works :-) 73, Gyula
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On Mon, 27 Jan 2020 19:24:45 +0800, you wrote: Sorry, can't get the file from
nor
/g/nanovna-users/wiki#nanoVNA-Partner,
Any suggestions?
Works perfectly with me, any firewalls or antivirus protection hyperactive? OE8UWW
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Hi Yes here it is Remember to set a frequency span e.g. 0.05 to 500Mhz then calibrate and save to e.g. location 0. Then follow the steps described in the right side I see you missed that Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] < [email protected]> P? vegne af reuterr@... Sendt: 27. januar 2020 06:03 Til: [email protected]Emne: Re: [nanovna-users] characteristic impedance On Mon, Jan 27, 2020 at 01:37 AM, Kurt Poulsen wrote: The nanoVNA partner does it semi automatic with a smart feature and a couple of mouse clicks Use nanoVNA Partner v0.20 link: <> Hello Kurt, Do you please have an example for measuring coax impedance with nanoVNA partner version 0.20 ? Unfortunately neb40gsm does not provide any help info. Attached is: nanoVNApartner0.20_Impedance_RG316-50cm.PNG screenshot nanoVNApartner0.20_Impedance_RG316-50cm.s1p S1P file 73, Rudi DL5FA
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No luck with that link. Bob On Monday, January 27, 2020, 12:02:04 AM PST, Gyula Molnar <gyula.ha3hz@...> wrote: Bob Albert
2:43am? #10292
Kurt, I went there and downloaded the file but am told it's corrupted.
Bob
Hi Bob, Please download from: neb sent it to me for testing, which I gladly did. Since I didn't get a detailed description, there are a few things I had to figure out ... but it still works :-) 73, Gyula
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No luck with that link.
..
Please download from: On e.g. Windows Chrome browser, right-click and select [ Save link as... ]
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That one is also no good. Bob On Monday, January 27, 2020, 09:37:49 AM PST, Oristo <ormpoa@...> wrote: > No luck with that link. ..
Please download from: On e.g. Windows Chrome browser, right-click and select [ Save link as... ]
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On Mon, Jan 27, 2020 at 04:32 PM, Kurt Poulsen wrote: Remember to set a frequency span e.g. 0.05 to 500Mhz then calibrate and save
to e.g. location 0. Then follow the steps described in the right side I see
you missed that
Hello Kurt, Sorry, I can not make it to work. Can you please tell me, what is the length of your coax cable and what type. I guess that your dip was at 500 MHz, right? But then a span of just 500 MHz is strange for me. It looks like, that I have a misunderstanding, but where? The program nanoVNA Partner behaves strange, if you do not make it right on the first try. I need to close it and restart after each try. 73, Rudi DL5FA
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Hi Bob - Please download from: That one is also no good.
Is nanoVNAPartner0.20.rar not downloaded? If it is, what utility are you using to unpack it. (FWIW, I use ) What operating system?
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Bob - it's not the downloaded files. If you're trying to unpack the archive using the built-in Windows utility - it won't work.Windows is only licensed for ZIP files, not RAR.
As Oristo said, download and install 7-zip from his link.
It's a great program to have as it allows you to go inside of ISO images as well as 30 other packing formats, RAR included.
Regards,Larry
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On Monday, January 27, 2020, 12:41:05 p.m. GMT-5, Bob Albert via Groups.Io <bob91343@...> wrote: That one is also no good. Bob ? ? On Monday, January 27, 2020, 09:37:49 AM PST, Oristo <ormpoa@...> wrote:? > No luck with that link. ..
Please download from: On e.g. Windows Chrome browser, right-click and select [ Save link as... ]
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Does not download, just gives me a screen of gibberish.
Bob
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On Monday, January 27, 2020, 09:53:29 AM PST, Oristo <ormpoa@...> wrote: Hi Bob - Please download from: That one is also no good.
Is nanoVNAPartner0.20.rar not downloaded? If it is, what utility are you using to unpack it. (FWIW, I use ) What operating system?
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Thanks Larry; I got the 7-zip but still can't get the file for the nano.
Bob
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On Monday, January 27, 2020, 10:02:50 AM PST, Larry Rothman <nlroth@...> wrote: Bob - it's not the downloaded files. If you're trying to unpack the archive using the built-in Windows utility - it won't work.Windows is only licensed for ZIP files, not RAR. As Oristo said, download and install 7-zip from his link. It's a great program to have as it allows you to go inside of ISO images as well as 30 other packing formats, RAR included. Regards,Larry ? ? On Monday, January 27, 2020, 12:41:05 p.m. GMT-5, Bob Albert via Groups.Io <bob91343@...> wrote: ? That one is also no good. Bob ? ? On Monday, January 27, 2020, 09:37:49 AM PST, Oristo <ormpoa@...> wrote:? > No luck with that link. ..
Please download from: On e.g. Windows Chrome browser, right-click and select [ Save link as... ]
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Can you download:
73, Gyula
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Kurt Poulsen
Gyula Molnar
Oristo
