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Re: errors of "error" models
#95.5: [SOLVED] : The "Mystery" of the Identical Results Using Different VNAs
Hello, Allow us, please, to announce that in the sequence of our three guesses in time : "Moebius" [#95.1], "Hardware" [#95.3] , and "dB" [#95.4], the very first of them is fulfilled : "Moebius" - the details are following. Sincerely, gin&pez@arg [#95.1] : On a Sufficient Condition for Identical Measurements Using Two Different VNAs 26 December 2019 - /g/nanovna-users/message/8657 [#95.3] : On the Sufficient Conditions for Identical Measurements Using Two Substantially Different VNAs - Our Research has been Completed 27 December 2019 - /g/nanovna-users/message/8669 [#95.4] : On the Analogy of Difference of Ratios but not of Ratios 27 December 2019 - /g/nanovna-users/message/8674 :#95.5 |
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Re: nanovna cases
#enclosure
Maybe you can share with us some files that one can convert to .stl to 3D
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print? I like the case very much. Cheers! 73 de Luis, CT2FZI <> <> On Fri, 27 Dec 2019 at 00:39, Gigabyte <steven.b.hoff@...> wrote:
That case looks really nice. Looks like it will keep a lot more dirt and |
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Re: Brief NanoVNA-H vs NanoVNA_F comparison
#nanovna-f
Herb,
You might like to post questions about the NanoVNA-F in its own group: /g/nanovna-f I'm sure the developers would appreciate your suggestion for new firmware features and extended frequency range. I expect many users would appreciate these features! Cheers, David -- SatSignal Software - Quality software for you Web: Email: david-taylor@... Twitter: @gm8arv |
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Plate RF Choke Measurements
#measurement
Re visit this topic as I am looking at plate chokes for a tube amplifier.
I used 1010 points from 100 kHz to 30 MHz. There are 3 chokes shown here. The older National R175 shown in a prior post with its problems of 2 in band resonant conditions, a 230 uH homebrew choke for 160 - to - 40 meter. Fine but horrible beyond 15 MHz and finally a fairly nice choke at 100 uH on a ceramic core complete with a 500 pF/20 kV bypass capacitor. This choke shows a single resonance but is out of band. It appears unnecessary to provide a short across the choke to pick up these loops if a shunt S11 measurement is used. In all cases the parallel resonate point crosses the open circuit side of the chart. A short across the choke simply rotates the reflection towards the short circuit side of the chart however the series loops stay in tact. Alan |
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Re: errors of "error" models
#95.4: On the Analogy of Difference of Ratios but not of Ratios
Hello, - - - - - - - - - (c) gin&pez@arg (cc-by-4.0) 2019 : start - - - - - - - This may be the result of measuring only levels and of measurements only in dB. - - - - - - - - - finish : (c) gin&pez@arg (cc-by-4.0) 2019 - - - - - - Sincerely, gin&pez@arg :#95.4 |
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nanovna cases
#enclosure
Just knocked up a case this afternoon in the mancave.
This case uses the existing screws in the nanovna, so should be easy to pop together like a six piece jigsaw :-) Acrylic/polycarbonate cut with CNC.. If there is any interest i can polish design..flatpack post.. price tba. Will get round to doing a desktop box version shortly display and sma's on the front usb/c on the rear, will post pictures when finished. |
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Re: errors of "error" models
#95.3: On the Sufficient Conditions for Identical Measurements Using
Two Substantially Different VNAs - Our Research has been Completed Hello, - - - - - - (c) gin&pez@arg (cc-by-4.0) 2019 : start - - - - - - Since any of the 6 involved differences into G-mini: G = (g-l)*(o-s)/[(g-o)*(s-l)-(g-s)*(l-o)] is of the form (g2-g1), it seems that the even simpler sufficient condition for Identical Measurements: g" = k*g' => (g"2-g"1)/(g'2-g'1) = (k*g'2-k*g'1)/(g'2-g'1) = k*(g'2-g'1)/(g'2-g'1) = k which theoretically results to the previous one [#95], may also be proved in practice as an adequate one for Identical Measurements, we check both conditions at those 8 frequencies on which we simultaneously have the following available results for both [NanoVNA] and [HP 8505A]: I/II. The 6 Ratios of Differences: Modulus: - we don't post images - we only post links to them - Argument: Conclusion: * A d e q u a t e * II/II. The 4 Ratios: Modulus: Argument: Conclusion : * I n a d e q u a t e * - - - finish : (c) gin&pez@arg (cc-by-4.0) 2019 - - - - - - - - - - Well, this is very Interesting, indeed. But it seems that, if someone is more interested on this, then he has to somehow dive rather deeply down to the technicalities of the hardware implementation. However, this is definitely not a subject for The Common User - like us. Therefore, we consider that our research on this subject has been also completed. Sincerely, gin&pez@arg [#95]: On a Sufficient Condition for Identical Measurements Using Two Different VNAs: 26 December 2019 - /g/nanovna-users/message/8654 :#95.3 |
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Re: Can the nanoVNA be used as a scalar spectrum analyzer ?
On 2019-12-26 21:07, David Eckhardt wrote:
For example, the SWR plot is scalar - no sign or complex portion involved.Thanks Dave, and all the others who answered. Well, I don't need to use the nano as a scalar spectrum analyzer, for this I already have a Rigol. I was just puzzled by the fact that moving the generator output by 100 kHz the displayed signal did disappear. But now that I have been remembered that only 101 points are scanned, everything is clear. Many tanks indeed, -- /*73 Alberto I2PHD* <<< >>>/ |
gin&pez@arg
CT2FZI
David J Taylor
Alberto I2PHD