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Re: New version of NanoVNA-Saver: 0.2.1
Hi, Rune!
Thanks for your answer in NanoVNA-Saver0.2.0 thread. I will continue here. There was a task to find out an impedance of unknown teflon coax cable, which looks like 75 Ohm. I did it with the help of NanoVNA TDR measurements. A 500 mm piece of 50 Ohm teflon coax cable with SMA connector was plugged into the device and a piece of unknown cable was soldered to its other end and left open. The results are on the device screen photo. Then I decided to do the same with the help of the built in TDR function of NanoVNA-Saver, as you suggested. What I saw in TDR window, looks correctly, but when I put marker on the curve, only distance was displayed, but not an impedance value. See the next screenshort. The impedance value can only be read approximately from the impedance axis. I think that it would be very useful to display an impedance under marker. After that I put device in TDR mode again, menu item - TRANSFORM/LOW PASS STEP and run Sweep in NanoVNA-Saver. The results were very interesting. TDR window displays something wrong. But ¡°S11R+jX¡± window seems to be alike device screen. See the next screenshort. The markers shows true values of impedance of two pieces of cables. Only horizontal axis is in MHz. :) I think, that it is one of the ways to measure transmission line impedance with NanoVNA-Saver. Thank you very much! Merry Christmas! 73! Andy, UA3RAW |
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Re: First PCB pictures of the V2
The design is to be finalized (last prototype verification) in a week. After that it depends on the manufacturer, but I'm guessing a month or so. However I may have a few excess prototypes that I can offer to software/firmware developers early for free (I'm not authorized to sell it).
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Re: errors of "error" models
#92 ' : Our General Picture of [TheLeastVNA] - Update
Hello, Allow us, please, to update our General Picture of [TheLeastVNA] [1] by * c o r r e c t i n g * its its very part referenced to Erik's, PD0EK arrows, in such a way that our new rephrasing to not be affected by any possible new look of his picture [2], that is as follows: " however, * A N Y * O T H E R * VNA operating in a similar way as a [LeastVNA], can be effectively considered as this 4-port [LeastVNA] above : e.g. the schematic one in the picture by Erik, PD0EK at [2]: where, the 4 Graphic Symbols shown at the whole upper half of it: (1) [Sinusoidal Generator] (2) [a0] (3) [b0] (4) [couple of opposite arrows a1 and b1, just before the DUT] also consist such a 4-port [LeastVNA]. Sincerely, gin&pez@arg REFERENCES: [1] #92: Our General Picture of [TheLeastVNA]: 24 December 2019 - /g/nanovna-users/message/8612 [2] Will do: 24 December 2019 - /g/nanovna-users/message/8635 :#92' |
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Calibration Algorithm
#calibration
Dear All,
I finally managed to get what I was looking for, but taking a somewhat lazy approach. I used the excellent open source scikit-rf Python library () developed for RF/Microwave engineering. To learn using it, I developed the attached small code to very quickly find the resonance frequency of a Magnetic Loop antenna (high Q factor/narrow bandwidth) tuned somewhere between 6 and 30 Mhz. For the calibration standards I considered ideal characteristics (zero ohms, infinite, 50 ohms) as I do not have a professional calibrated kit. Purists might be shocked with my coding style, but it has the advantage to be easily understood by beginners like me. You are of course welcome to modify and improve it, and if so, please share your work. The code was attached for those who would like to use it as a snippet for other applications, but due to a lack of time, I can unfortunately not make any commitments as regards support. Thank you for your understanding Enjoy! 73 de HB9IIU Daniel P.S The App was developed, and is running on a Raspberry Pi which I access with my Mac via VNC App in action: |
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Re: First PCB pictures of the V2
On Tue, 24 Dec 2019 at 15:43, Daniel Marks <profdc9@...> wrote:
edy555, I must admit that I find it annoying that I released ATLC under the GPL then find someone else has released ATLC2 which is very similar in function. To be fair, the author does state ¡° This program was inspired by the *atlc* program written by Dr. David Kirkby, G8WRB¡±. However, I wish a very different name had been used by the author of the other program, as I receive questions about a program that I never wrote. I have never checked to see if the other program has a single line of code that I wrote. That would not bother me at all, as I released the code under the GPL. If you release code under the GPL, then you are inviting others to use it. But it is a bit annoying to have someone else write a program totally independently, and call it by a name that associates it with oneself. I think next time I release code under the GPL, I will write something in the source code *requesting* that others don¡¯t use a similar name if they write a similar program. Few of us are going to go to the expensive of registering a trademark in lots of countries, for items or code we give away free. Even if one did, it would be uneconomic to try to enforce it. Dave Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@... Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales, company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom |
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Re: First PCB pictures of the V2
Can you be more specific as to what copyright you are referring to? The hardware is our own design with nothing taken from your design, and the firmware uses your UI code in compliance with the GPLv3 (as stated in your source code). The name "NanoVNA" is a generic street name by now because there is no registered trademark and everyone is already selling under this name. I'll talk to my customer about possible name changes but as I said we are a contractor and it isn't under our/my control.
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Re: errors of "error" models
@Erik, PD0EK - 24 December 2019: /g/nanovna-users/message/8632 :
Dear Erik, Take into account, please, that we already * c o r r e c t l y * rephrased what you are quoting -obviously by mistake- with your above message, with our message: /g/nanovna-users/message/8630 , and allow us, please, to definitely point that we showed the way in which it is proved what you are saying, by our message: /g/nanovna-users/message/8618 . By the way, in addition of your Maxima code, of which we are still expecting its correct results, after we answered what you asked from us, with our message: /g/nanovna-users/message/8482 , would you also correct, please, your picture currently existing at your website at: , because its contents appear -at least to us- as to be self-contradictory ? Kind regards - gin&pez@arg |
gin&pez@arg
Andy UA3RAW
OwO
Pablo E. Untroib
Dr. David Kirkby, Kirkby Microwave Ltd
Jim Allyn - N7JA