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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* <<< >>>/ |
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Can the nanoVNA be used as a scalar spectrum analyzer ?
Maybe, or better, surely, something is escaping me....
I connected CH1 of the nanoVNA to a calibrated generator, set to -20 dBm, 10 MHz output. I set the nanoVNA for a Center Frequency of 10 MHz. The Stop Frequency automatically did set at 19.9 MHz. What I saw on the nano screen was what I expected, a peak just at 10 MHz, albeit the cursor indicated an amplitude of slightly less than - 6dBm, but my concern is another.. At this point I set the frequency output of the generator at 9.9 MHz. What I did expect was to see the peak on the nano moving a bit to the left, to 9.9 MHz... No... the peak disappeared completely... a flat blue trace at the bottom of the screen.... There is surely something escaping me, but what ? TNX for any clarifications, -- /*73 Alberto I2PHD* <<< >>>/ |
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Re: errors of "error" models
#95.1 : On a Sufficient Condition for Identical Measurements Using Two Different VNAs
Hello, Well, we think that this "phenomenon", that may looking as a rather unexpected one, but in fact we searched for something like it in the last few months, has to do with the many, very interesting all, properties of M?bius transformation: Sincerely, gin&pez@arg :#95.1 |
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Re: errors of "error" models
#95: On a Sufficient Condition for Identical Measurements Using Two Different VNAs
Hello, - - - - - - (c) gin&pez@arg (cc-by-4.0) 2019 : start - - - - - - Allow us, please, to announce that we just verified experimentally one of the theoretically sufficient conditions we found, in order to take identical measurements using two different VNAs, e.g. our [HP8505A] and our [NanoVNA]. Specifically, the theoretically sufficient condition, that we found and verified, concerns the most common case of using a [LeastVNA] for measuring Nominal Values without Uncertainties with the loads S, L, O having Nominal values of ( -1 , 0 , +1 ), respectively and obeying our G-mini equation: G = (g - l) (o - s) / [ (g - o) (s - l) - (g - s) (l - o) ] Well, if the following relation holds: (g"2 - g"1) = k (g'2 - g'1) where (g"1 , g"2) , (g'1, g'2) are pairs of measurements using a [VNA"] and a [VNA'] respectively, resulting from the same pair of loads (G1, G2), then we have immediately: G" = (g" - l") (o" - s") / [ (g" - o") (s" - l") - (g" - s") (l" - o") ] = = k (g' - l') k (o' - s') / [ k (g' - o') k (s' - l') - k (g' - s') k (l' - o') ] = = k^2 (g' - l') (o' - s') / [k^2 { (g' - o') (s' - l') - (g' - s') (l' - o') } ] = = (g' - l') (o' - s') / [ (g' - o') (s' - l') - (g' - s') (l' - o') ] = = G' Thus, using as [VNA"] our [HP 8505A] and as [VNA'] our [NanoVNA] with our three 3 HP Standards S, L, O, as well as our -repeatedly mentioned- One-Port Standard of 50 Ohm DC, we just found at 405 MHz, in ordered pairs (modulus, argument in degrees) the following almost identical results: (g" - l") / (g' - l') = ~( 12 , - 137 ) (o" - s") / (o' - s') = ~( 12 , -136 ) (s" - l") / (s' - l') = ~( 12 , -135 ) (g" - o") / (g' - o') = ~( 12 , - 138 ) (l" - o") / (l' - o') = ~( 12 , - 138 ) (g" - s") / (g' - s ') = ~( 12 , - 135 ) which results in a mean value of k = ~( 12 , 136.5 ), and thus verifies experimentally at 405 MHz, our above sufficient condition. We repeated the same procedure at 639 MHz and we concluded that * m o s t * o f * a n y * o t h e r * c h e c k * these results may explain fully: #30 : our final report 1 - 4 Oct 2019 /g/nanovna-users/message/3989 - - - finish : (c) gin&pez@arg (cc-by-4.0) 2019 - - - - - - - - - - Sincerely, gin&pez@arg :#95 |
gin&pez@arg
Alberto I2PHD