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Re: spreadsheet for importing snp files, Excel 2010
Hi Ed,
Well...new day! Raised in the woods...literally...in N Maine. 2-room school. No electricity until I was 10. Traveled quite a bit after 18. Spent a lot of time in Ca, including visiting Sausalito. Lived in SF, N of SF later, then San Clemente, and Oceanside. Now back in New England. Not often to hear of someone from the area, though there are a lot of active hams in New England. We test 5-10 per month, new and upgrades. Your cell ¡°M4¡± states value of RLdB = 35.9176dBI see you are one of those folks who like "smart" quotes...apparently, my email is too dumb to understand them. Sigh. Like me, like my email ;-) Actually L4 in my copy... Small fix.Not necessary...as I posted in the thread, the point of the spreadsheet is just to give folks the tools do as they like. No warranty expressed or implied. Feel free to use it as ye will. ~R~ 72/73 de Rich NE1EE The Dusty Key On the banks of the Piscataqua |
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Re: Nanovnasaver plots
Thanks Roger for pointing this out. Knowing one's measurement tools is the
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basic rule here. Thanks for pointing out. I have also checked my NanoVNA. If I measure the Zload of port 2 (using Port 1, so using a calibration Through connection and measuring port2's S11). I get the following |Zload| of port 2: [image: afbeelding.png] This is ok-ish IMHO (variation some 0.1ohm (less than 0.2%). There is a deviation from 50ohm (around 05%), but this could be partly due to inaccuracy calibration Load (measured with DVM: 49.7ohm). I don't think the Zload (|Z| of port2/load) is problematic. If I measure metal resistors (averaged between 300 and 1800kHz) using Reflection and Series S21 I method, I get the below |Z| values. I also give the R values measured with DVM [image: afbeelding.png] [image: afbeelding.png] So indeed |Zrefl| does not deviate much from the DVM value (<2%). The |ZseriesS21| though differs quite a lot (~9%) from DVM value and looks to be proportional to the resistor value. Where is this 9% error coming from? A 9% error is large! I don't think the deviation of the port2 load (Zload) from 50ohm is problematic (only some 0.2%). Looking at the Zsourse (the impedance of port 1): would that not be close to Zload (impedance of port2, I hope/assume...). But that one is compensated using the SOLTI method, or not? I understand the missing of 12-term correction is the other problem (as stated by Owen Duffy: ). Who has a procedure for this? I could not find this on the web (Owen Duffy refers to it, but I don't see a procedure). Something must deviate some 9% from the 'my norm', but what? I tried to simulate this by varying Zo, Zload, Zsource; but I can't find really realistic values to cater for the variation see in ZseriesS21 (I need to bring Zload back to some 40ohm to cater for this 9%, but then some other Z values (|ZseriesS11|) don't match properly [and it is not measured, see above!];-). Any help to understand this is appreciated. Thanks. So at this moment I agree that 2port Series method does not produce good values. All the best, Victor Op di 31 mei 2022 om 23:07 schreef Victor Reijs via groups.io <pe1atn.victor.reijs@...>: Hello Roger, |
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Re: spreadsheet for importing snp files, Excel 2010
Hi Ed,
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Just returned home...don't have an nVNA handy... There are 2 questions on the table. 1. What does the H4 show for FORMAT > LINEAR? ans: LINEAR - Magnitude (absolute value) of Sxy. That's if I recall correctly. That's why the Linear col in the spreadsheet calculates | S11 |. The user manual is an attempt to lay out for folks what the H4 is doing...for example, when I first saw LINEAR, I wondered what that could be. I don't associate the word "linear" with "absolute value", "Euclidean norm", or "p-norm", where p=2. So I took a data set, and, using the same data (not scanning), changed the formats to see what they displayed. I /think/ that if someone fires up an H4 and sets the display format to LINEAR, they will find it is | S11 |. If that turns out to be the case, then right or wrong, that's what LINEAR means in an H4. 2. What does "one_port.pdf" say? Well, to begin with, not the point. The point is to document what the H4 is doing, whether or not it is doing it correctly. Then..."one_port.pdf" says Just as for the Return Loss, the VSWR (dimensionless) is calculated from rho...(11) where 1+rho = 1+| S11 | seemingly suggesting that rho is the magnitude of S11. I havna really read the doc... I welcome discussion... On 2022-06-05 08:22:-0700, you wrote:
It ain¡¯t. |
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Re: Where to buy
On 05/06/2022 18:09, Siegfried Jackstien wrote:
hi RogerFor example: JNCRADIO SV4401A - 4.4G VNA WITH 7'' CAPACITIVE TOUCHSCREEN Sysjoint. David GM8ARV -- SatSignal Software - Quality software for you Web: Email: david-taylor@... Twitter: @gm8arv |
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Re: Where to buy
On Sat, Jun 4, 2022 at 08:28 AM, Vince Loschiavo wrote:
There are many "NanoVNA" products on the market - NanoVNA-H, NanoVNA-H4, NanoVNA-F, LiteVNA, LiteVNA64, LibreVNA, NanoVNA SAA2, NanoVNA-F V2, SV4401A, V2Plus, V2Plus4 and several more.... What is best for you depends on your requirements in terms of budget and specifications. - standalone or PC required to operate - maximum frequency of interest - dynamic range of S11 and S21 - screen size (2.8", 4" or 7") - connector type (SMA or N connector) - metal or plastic case - measurement capability (antenna measurements only or measuring components, filters etc. ) - product support (documentation, manuals, user groups) There is no table comparing all the products on the market. If you let us know what you want after considering the above we can point you in the right direction. Roger |
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Re: spreadsheet for importing snp files, Excel 2010
On 2022-06-04 10:40:-0700, you wrote:
Looking at formulas on the spreadsheet, "Linear" ( Column G) contains the absolute value (magnitude) of S11,The user manual states that it is the | S11 |. I think that "Linear" is a bit of a misnomer, but it is what it is until it ain't. ~R~ |
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Re: Where to buy
On 2022-06-04 08:28:-0700, you wrote:
I would like to purchase a later version of the nanoVNA.I have had good experiences with several purchases from AURSINC. -H, -H4, RF Demo Kit, etc. I have purchased from them for 2 years. ~R~ |
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Re: an Old NanoVNA-H
Thanks for all the info.
It currently works well for what I'm doing...so i might leave well enough alone. Not worried about doing firmware upgrades, my rigs get regular updates.. did have a bit of an issue loading driver, (win 10 64bit) looks like the port is good as it comes up with STMicroelectronics Virtual COM port fine when i go to DFU, it comes up in other devices as a STM32 BOOTLOADER..it doesn't show up as STM Device in DFU Mode Tried to load the 32 bit driver just in case but it didn't want me to...Ha.. I'll do some more looking, as Device Mangler has the yellow triangle and exclam and installing DfuSE_Demo didn't help I'll keep at it.. thanks again Vince |
Rich NE1EE
David J Taylor
Roger Need
Gary W9TD
Vince N2AIE