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Re: errors of "error" models
@Gary O'Neil , N3GO - 17 December 2019
/g/nanovna-users/message/8292 Dear Gary, Thank you. Well, we are now proceeding carefully, step-by-step, by multi-checking and cross-verifying the results with all available independent procedures, including the [NanoVNA] internal one, as well as both of these you are mentioning, because our two experimental two-ports are consisting of DC Resistive Taus, with a third one being under construction, having in our minds to demonstrate all possible cases by three, representative, as much as possible, practical applications - if it is possible at all, of course, since we don't know and we will see. Anyway, up to now all of the results are too encouraging - permitting a cautious optimism - but we will see. #78'' : #78' was re-corrected 20 November 2019 /g/nanovna-users/message/7272 #80: [S]-parameters from [Z]-parameters 2 December 2019 /g/nanovna-users/message/7657 Best regards, gin&pez@arg |
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Re: New version of NanoVNA-Saver: 0.2.1
Hi Lajos
How are calibration directly at the female adaptor of the VNA using the short and load standard only omitting the open standard ?? If you are using my female calibration setting with test cables and using the NanoVNA supplied female female adaptor you do get poor calibration due to loss in this adaptor Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] <[email protected]> P? vegne af pgc1682@... Sendt: 16. december 2019 22:17 Til: [email protected] Emne: Re: [nanovna-users] New version of NanoVNA-Saver: 0.2.1 Hi Ron, Thanks the reply, that could be the problem. Many clones exist, maybe my Hugen like (not know) device calibrators not same than others. I try use nanovna default 50fF C0 or data from Kurt example. Nowadays I can not get good calibrations. Avarege only calibration currently I have. 73, Lajos |
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Some test results using a NanoVNA
I recently updated my blog with two posts showing the measuement results I have obtained using a NanoVNA.
one shows the response of a multiband HF antenna. The latest one shows the response of a step attenuator I recently built. I must say that I am more than pleased with the results I have been able to obtain with such an inexpensive instrument. It has been interesting following some of the discussions about calibration and the math involved with the VNA, but I am more interested in what people are using it for real world applications. -- DuWayne? KV4QB |
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Re: New version of NanoVNA-Saver: 0.2.1
Hi,
From Kurt very good measurement with good calibrated s1p file used, I interpolate several point. Original data is 101 point. See the attachment, what's happening if I modify the points to 100, 101, 102 and 1011 point. Original 101 point data very good, interpolated data not. I think interpolation also affects the accuracy of the calibration. 73, Lajos |
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Re: New version of NanoVNA-Saver: 0.2.1
Hi,
Great idea the higher resolution graph on nanovna saver. I mesured the very non ideal indoor 40 band antenne. The goal construct special tuner to shift 20 meter band electrically. I sweeep 6-15Mhz with osl calibration on nanovna, and nanovna saver calibrated too 10x101 point = 1010 point for better resolutuion. I re check calibration on nanovna and nanovna-saver, which is good. Open, shor, load good small point. See attached images. With Sim Smith Chart original 1010 point segmented sweep has ripple. Original sweep now reduced to 101 point. Now ripple disappeared, of course the some detail too. Use 1:1 view on picture viewer, small ripple exist if not original size displayed. 101 point data useful on low memory nanovna and for beginnniers. For advanced users i think segmented method very useful on nanovna-saver. It will be more precise if use raw data from nanovna. I not know how to nanovna works, I see QRP firmware has a scanraw command. I think this is what we need. I think raw option is useful, but not for all user. So checkbox required. I have calibration errors, i will send it next message. For calibration, interpolation beetween real calibration causes a strange error. 73, Lajos |
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Re: errors of "error" models
@Oristo - 4 November 2019 - /g/nanovna-users/message/6439
Hello, Allow us, please, to thank you at last for your most motivating us comments, regarding the relative values of s and o, as well as that one of l values, because it is only now, after the verification of our last research findings, we are feeling able to recognize the significance of these remarks made by you. Thank you. Sincerely, gin&pez@arg |
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Re: errors of "error" models
#86': UPGRADE : On the Results of Measuring Two-Ports Using Only [NanoVNA]
Channel [CH0] or a [LeastVNA]. - #86: On the Results of Measuring Two-Ports Using Only [NanoVNA] Channel [CH0]: 16 December 2019 - /g/nanovna-users/message/8275 Hello, Allow us, please, to announce that just we also additionally realized, in our sow, the following simple facts, always facupov, of course, and thus we just upgraded our previous division of the values involved in "Measuring Two-Ports Using Only [NanoVNA] Channel [CH0]" and now : "or a [LeastVNA]", as follows: - - - - - - (c) gin&pez@arg (cc-by-4.0) 2019 : start - - - - - - (0) All values are expressed as (complex) (couples of) rational numbers of finite length, but we can divide them to three 3 different sets, according to their different origin, form, and precision : (1) The set of nominal values of the three 3 Standards S, L, O, as they are given by their manufacturer in the usual form of { -1, 0, +1 }. These numbers are exact. (2) The set of 4 measured values : { s, l, o, g }, in the form provided by the manufacturer of [NanoVNA], his current version of the updated firmware, or the [LeastVNA] in use. These numbers are of fixed precision. (3) The set of finally computed values, that is either the { S12S21, S22, G } or just the {G} alone. The form of these numbers, as well as their precision, which nowadays may be arbitrarily high and limited only by the available application, computer memory, and run time, are defined by The Common User. - - - end : (c) gin&pez@arg (cc-by-4.0) 2019 - - - - - - - - - - Sincerely, gin&pez@arg :86'# |
gin&pez@arg
Kurt Poulsen
DuWayne Schmidlkofer
Oristo