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Re: New extended Tutorial Version 1.5. for the NanoVNA-H
Hi Piotr
The link is as follows to my document and female calibration NanoVNA-H.pdf Please note that the female female adaptor you have been supplied with the NanoVNA might differ. The Hugen-H supplied from end of October has a female female adaptor with low loss and the earlier delivered has much higher loss and different delay if length differ. In the document the female female delay is 50.7ps and has a length end to end off 15mm. The previous delivered female female adaptor has the same length but as said higher loss. If you have another female female adaptor test it after S21 calibration with the previous supplied one, and if it show S21 dB trace above the reference line (showing gain) it has lower loss and use it. After my best memory we are dealing with 0.3dB difference and also obscure the calibration when used for female kit calibration. If it has a different length then adjust the delay with 4.796ps per mm length difference Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] <[email protected]> P? vegne af Piotr Wozniak Sendt: 24. december 2019 14:23 Til: [email protected] Emne: Re: [nanovna-users] New extended Tutorial Version 1.5. for the NanoVNA-H Hi Gunthard, In your file you refer to "Calibration data for the NanoVNA with the supplied SOLT - Calibration set". I spent hours trying to find this file, without success. Could you (or someone else) give me a link? I saw this file somewhere in the past, but unfortunately didn't save it. |
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Re: New extended Tutorial Version 1.5. for the NanoVNA-H
See
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73 Arie PA3A Op 24-12-2019 om 14:23 schreef Piotr Wozniak: Hi Gunthard, |
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Re: errors of "error" models
Thank you Erik!
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73 Arie PA3A Op 24-12-2019 om 09:20 schreef erik@...: To help understanding the impact of the various terms of the complete G formula |
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Re: errors of "error" models
#93: On the Simplified Virtualization of the General Picture
Hello, - - - - - - (c) gin&pez@arg (cc-by-4.0) 2019 : start - - - - - - Allow us, please, to continue with the finalization of our picture: towards to that approximated one, which we already called it a virtual two-port. This can be achieved by expressing the reflection coefficient G, of a load or DUT connected at T Test Port, that is by the ratio of the ("reflected") output signal bT from T port (that is the one caused by the voltage wave directed from inside-to-outside of T port or by a "reflected" to T wave), to the ("incident") input signal aT to T port (that is the one caused by the voltage wave directed from outside-to-inside of T port or by an "incident" to T wave): G := bT/aT in terms of the ratio of the two separate signals aA and aR, * B O T H * I N P U T * ("incident") to the ("receiving") ports A and R, respectively: g := aA/aR This is possible and results -after a really tedious work, if someone selects to do it without some lower of the high mathematics- to the form: G = (Ag + B)/(Cg + D) where A, B, C, and D are rather complicated expressions of various Sij. However, with a careful, technically appropriate, adjustment of the whole of Sij values, it is possible a simplification of these expressions by approximating, diminishing or reasonably ignoring a lot of various signal paths in the above 4-port signal flow diagram: Well, this a most fortunate fact, indeed, because makes possible various "error" models of VNA measurements, with each one of them to take the name of the number of finally kept terms, the remaining ones after the deletion of the rest of the others. And it is only in this way that also the so called "3-terms error model" results, forming something that reminds strongly a two-port network. But, since in this way only the T port is clearly shown, while the other one is a totally absent from the reality, we thought to define a Virtual measurement Port, as we already presented it at: #85: On the Formation of a Virtual Port: 25 December 2019 - /g/nanovna-users/message/8237 - - - finish : (c) gin&pez@arg (cc-by-4.0) 2019 - - - - - - - - - - That's all. With the best of our regards to all Members who insist to read this thread, gin&pez@arg 93#: |
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Re: QEX Magazine
#tutorials
Two thoughts here:
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1) A great time for two or three or more hams getting together and jointly buying a subscription to QEX, AND making it available to their club. And you can jointly purchase the DVD at the end of the year and donate it to the club. You don¡¯t belong to a club? So sad. Start one. We did years ago out in Missouri while I was in school. Put an ad in the local paper (or eblog now) and a few interested folks came out of the woods and the club started. Mainly as a coffee round table but later a formal club. I also belong to two clubs, one with a formal schedule and the other just a breakfast gathering without all the rigamarole..... both very enjoyable and educational. 2) One of our club members brought in his Airspy HF+ (Yes, just the less expensive HF+) and showed how to use it as a spectrum analyzer.... I was blown away with the simplicity of it. We were testing the QRP Guys FT8 xcvr vs the Crkits D4D xcvr build.... a lot went over my head but a neat use of a simple DSP tool for those who want to experiment or test things. These Airspy (and other DSP thingies) aren¡¯t just another radio for listening to short wave. They are more like a piece of test gear than any radio you will ever own. David J. Wilcox K8WPE¡¯s iPad On Dec 23, 2019, at 3:58 PM, David Eckhardt <davearea51a@...> wrote: |
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Re: errors of "error" models
@Erik, PD0EK - 24 December 2019:
/g/nanovna-users/message/8615 /g/nanovna-users/message/8614 Dear Erik, Allow us, please, to carefully reserve ourselves from commenting on matters, which either excerpt engineering techniques applied, more-or-less successfully, in the time domain with the obscure purpose to also apply them in the frequency one, or on those mixing-up probabilistic techniques with deterministic ones, or to say it most simply and for the third time, if we are correctly counting : we are not able at all to correct perhaps down to zero the Uncertainties of the Standards, as they are given to us by their Decent Manufacturers; the only thing we can do is to propagate these Uncertainties through that simple formula to its G results, and then, its G results through that well-known one to Z results, and thus to finally to express the unavoidable Core Uncertainty of Z measurements. Yes! We perfectly understand that this is a most unpleasant fact, but what can we do? That's Life - a Scientific one, of course. Best regards, gin&pez@arg |
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Re: errors of "error" models
@Gary O'Neil, N3GO : 24 December 2019
/g/nanovna-users/message/8610 Dear Gary, Alright then ! Now we see... Well, allow us, please to avoid any further discussion on such matters, simply because we don't find what we can say except to ask you, please, to advise the interested Non-Common User to ask the Decent Manufacturers, why they still prefer to sell Standards marked with Uncertainty Values, instead of cancel it using "correction polynomials", so to be able to invoke these very "correction polynomials" as their excuse for zeroing the Uncertainty during their defense before the appropriate Mercantile Court... : D With our best regards, gin@pez@arg |
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Re: errors of "error" models
#92: Our General Picture of [TheLeastVNA]
Hello, Allow us, please, to inform you that we just uploaded our general picture of a 4-port [LeastVNA] at: Well, as we already wrote in #84: On the Virtuality of the "Measurement Port" [1], although we shaped this general picture from the HP8502A unit: 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 upper-left corner: [Sinusoidal Generator] - [a0] - [b0] - [couple of opposite arrows a0 and b0] also consist such a 4-port [LeastVNA]. Sincerely, gin&pez@arg REFERENCES: [1] #84: On the Virtuality of the "Measurement Port": 15 December 2019 - /g/nanovna-users/message/8225 , although [2] /g/nanovna-users/message/8105 #92: |
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Re: NanoVNA Presentation
#measurement
#nanovna-saver
#tutorials
Hi,
On Monday, 23 December 2019 20:11:10 GMT Tominaz wrote: look in the trash folder and all mail sent, could still be there.I resent the email to Luc which he has recieved OK now. FYI I am new member to the group and a new owner of a nanoVNA and I must say there is a wealth of information to be found for this excellent device, here and in the groups files and FAQ. Most helpful for a new user like me, but some of it is a bit of a steep learning curve :-) It's a great addition to my test gear. Seasons Greetings! 73 Colin - G6AVK -- Fedora 31 (Thirty One) |
Kurt Poulsen
Andrew Harmon
Arie Kleingeld PA3A
gin&pez@arg
David Wilcox K8WPE
Colin G6AVK