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Re: #nanovna-saver
#nanovna-saver
Hi Ulrich,
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are you still having these crash issues? If you are, could you try running the software from a command prompt, and looking at what messages it writes there when it does crash? Running it from a command prompt (cmd.exe) prevents it from closing the window that has the error information in it. That would be most helpful to me! -- Rune / 5Q5R On Wed, 5 Feb 2020 at 13:49, UlrichKraft <kraftulrich1@...> wrote:
Hello |
Re: Which Chart(s) for Which Measurement(s)
Hi Alan,
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Differential group delay sounds interesting - I'd have to have a further explanation of what it is, and how to calculate it, though ;-) But it's probably something that can be added in over time! :-) With regard to return loss - some people want it one way, some people want it the other, both sides see their way as the right way - and both ways are supported in the application! ;-) -- Rune / 5Q5R On Wed, 5 Feb 2020 at 21:17, alan victor <avictor73@...> wrote:
Hi Chuck, |
Re: #nanovna-saver Impedance value /Z/
#nanovna-saver
Hi Ulrich,
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thanks for your suggestion! I will look at adding |Z| as a marker value for the next release of NanoVNA-Saver! :-) -- Rune / 5Q5R On Wed, 5 Feb 2020 at 14:02, UlrichKraft <kraftulrich1@...> wrote:
Hello, |
Phase curve - explanation
Hello guys,
I¡¯m extensively playing with my Nano.. Could anybody help me to understand the phase curve? It¡¯s clear that is shows resonance point when there is rapid change in phase (almost vertical line) but I can¡¯t understand where the angle is measured... Why it is somehow related to 90dg (remark in the marker line)? The value are from 0 to 180 and from 0 to -180dg... where is the vector start point? I can¡¯t imagine the vector in the Schmidt diagram... Could you lead me to some document or tutorial to get the point? Thanks Stepan |
Re: Portable full 2-port 6 GHz VNA from YL3AKB
I agree as well; the ability to work with 5.8Ghz / 3.6Ghz gear is pretty important to me and I assume would gather a lot more interest from WISPs (and other related commercial /hobby interests). The RF hacking community is really exploding lately as well.
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If 6Ghz could be done decently for anywhere near $150 or sub $200, that would be unbeatable. I'm pretty sure 5.8 is where you will pick up a lot more interest from a much wider audience, rather than "just us hams". I personally will be waiting for that magic 5.8Ghz capability, before my next inexpensive VNA purchase. I wonder if we could get one of the larger RF related youtube channels to do some public polling on this.. - Thank you, Gus Osborne KI4WYY - Thanks! Gus Osborne Assurance Technology, LLP On Feb 6, 2020, at 11:16, Randall Steffens II via Groups.Io <pomology@...> wrote: |
Re: Correct measurement procedure for a single quartz crystal
Bob Albert
The problem with measuring crystals is that the nano does not have small enough frequency increments to characterize such a high Q device.
What I did was connect the crystal from the first port to ground but it amounts to almost the same thing.? The Smith chart shows a loop around the crystal resonance and you can walk the marker around the loop to find the resonant frequency.? This only works nicely for low Q crystals.? I had one crystal of such high Q that the nano was unable to hit its resonance. Bob On Thursday, February 6, 2020, 08:52:49 AM PST, aparent1/kb1gmx <kb1gmx@...> wrote: TO get 1hz resolution with 101 points you need very narrow sweeps so VNA-saver is likely the tool to do that. Even with 10hz that only 1000hz sweep and likely not wide enough. Also if you sweep too fast the crystal will ring and you get a tilted result. Without using software to splice multiple sweeps its a battle of precision and number of possible points. Even with a big? VNA/PNA a lot of points (4096) at 1hz resolution and a slow sweep (at least 40mS per point) was needed. Allison ----------------- No direct email, it goes to bit bucket due address harvesting in groups.IO |
Re: Portable full 2-port 6 GHz VNA from YL3AKB
Exactly my thoughts Bob! A 6GHz capable unit is high on my priority list for the same reasons.
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73, Randy NC8U On Feb 6, 2020, at 9:03 AM, Bob KV4PC <robert.ehresman@...> wrote: |
Re: Portable full 2-port 6 GHz VNA from YL3AKB
There is lots of discussion in this thread about what the market is.
I understand there is a calculus regarding cost vs how units will sell and there exists a perception of what the community wants these for. I am a ham and an ARES member, and the group that serves my county is interested in setting up a high speed Mesh Radio data network. My perception is this particular desire amounts to a world wide movement. Within the hobby, the technologies are referred to as High Speed Multimedia (HSMM), Broadband Hamnet (BBHN), Amateur Radio Emergency Data Network (AREDN) and others. There are also groups, not necessarily hams, setting up networks entirely within the confines of ISM unlicensed operations. As such, the equipment used are consumer grade hackable WIFI access points, brick amplifiers, filters, commercial antennas, and the like. The bands of operation range from 70cm to 5cm, with the bulk of equipment being used operating at 2.4, 3.4, or 5.8 GHz. This is, in my opinion, is the Amateur market for a lower cost 6 GHz capable VNA, and my own primary interest in owning such as this. While it may be true that the mesh radio experimentors are largely a plug and play crowd who dont build much from scratch and buy their antennas, sadly there is alot of junk on the market, or antennas being marketed with exuberantly exaggerated specifications, or shipped with manufacturing defects and an instrument to confirm performance would be a game changer. It is my belief that microwave experimentors of this class may be very receptive. 73; Bob KV4PC |
Re: #nanovna-h4 stops at boot screen
#nanovna-h4
Hi Herb
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Thank you for the comment. I like you sense of humor ? Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] <[email protected]> P? vegne af hwalker Sendt: 1. februar 2020 03:16 Til: [email protected] Emne: Re: [nanovna-users] #nanovna-h4 stops at boot screen On Fri, Jan 31, 2020 at 04:05 PM, Kurt Poulsen wrote:
Hi Hugen Please also take action on the opening for the USB C connection which is blocked for entry by excess material of the upper part of the case. The hole need enlargement by milling off the "lip". Also what to do about many stray trace / dots from previous traces ? ============================================== Kurt, I submitted an issue report to hugen about the USB-C port opening along with the center frequency above 1 GHZ lock-up at <> . In my "Hints and Kinks" for the NanoVNA-H4, </g/nanovna-users/message/10354> /g/nanovna-users/message/10354 , I noted the stray artifacts remaining from previous sweeps. Some times the only way to clear a stray artifact is to manually force a refresh by going into the Display->Trace menu and deselecting and reselecting a trace. I really only need to do this if I am performing a screen capture and want to clear any stray artifacts before hand. After updating to the January 18th, 2020 release, I don't seem to get the really persistent artifacts as often, but they are still there. I'm guessing the firmware currently does not do a complete refresh between sweeps, but with the faster F303 processor I would think it would only be a minimal penalty for doing so. I'm pretty much just waiting for the completion of Chinese New Year before I expect any firmware updates to address the issues. You are the only one besides myself who has complained about the stray display artifacts on this forum, so I haven't submitted a GitHub issue about it to hugen. I don't make it a habit of submitting an issue report until at list one other person has verified it. You can always tell the early users of new hardware or software, they are the ones with a few arrows sticking out of their backs. - Herb |
Re: Correct measurement procedure for a single quartz crystal
aparent1/kb1gmx
TO get 1hz resolution with 101 points you need very narrow sweeps
so VNA-saver is likely the tool to do that. Even with 10hz that only 1000hz sweep and likely not wide enough. Also if you sweep too fast the crystal will ring and you get a tilted result. Without using software to splice multiple sweeps its a battle of precision and number of possible points. Even with a big VNA/PNA a lot of points (4096) at 1hz resolution and a slow sweep (at least 40mS per point) was needed. Allison ----------------- No direct email, it goes to bit bucket due address harvesting in groups.IO |
Re: Correct measurement procedure for a single quartz crystal
I use this formula for the motional capacitance:
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Cm = (f1 - f2)/(2*PI*f1*f2*Rt) Where f1 and f2 are the upper and lower 3 dB points, so you could just say BW for f1 - f2. In the denominator, f1*f2 is not far from fc^2 where fc is the resonant frequency of the crystal so you can use fc^2 if you like. Rt is the total resistance of the circuit. So assuming you have a 50 ohm generator plus 50 ohm detector and you measured the loss resistance of the crystal at resonance at 55 ohms, your value is 155 ohms. Having found Cm, Lm is the value of inductance that has the same reactance as Cm at the resonant frequency. But a formula for that is: Lm = 1/(4 * PI^2 *f^2 * Cm) Where f is just the resonant frequency of the crystal. You'll probably wind up with Cm in femtofarads and Lm in millihenries. All of this depends of the resolution of the VNA. Being able to get down to 1 Hz resolution can help. I tried one crystal and didn't think I got good results. But in the nanoVNA notes by Wes Hayward linked here recently, he seemed to get some good crystal measurements. And Hayward is the guru of crystal measurements although he wasn't deriving motional parameters in his paper. In doing crystal measurements, people often use transformers or resistive pads to put the crystal in a 12.5 ohm environment, meaning the crystal sees 12.5 ohms looking in either direction. I'm not sure how advantageous this is, but it does lower the BW and so would seem to make fine resolution even more important. For parallel capacitance, generally using a low frequency capacitance meter like the AADE or eBay clones works. 73- Nick Kennedy, WA5BDU On Thu, Feb 6, 2020 at 9:45 AM stefano bello <festecate@...> wrote:
Hi all, |
Re: Issue with nanoVNA-Saver in at least the last several versions.
Oristo and Alan,
When I started I thought this was a problem in both VNAs. But, you are right. I will post it on the other group. There remains an issue with nanoVNA-Saver and how it treats a response of 0.0 + j0.0 from an S21 measurement of a VNA. Thanks for your help. -- Bryan, WA5VAH |
Correct measurement procedure for a single quartz crystal
Hi all,
I wonder which is the correct procedure for testing a Crystal quartz. Nano VNA has 0.6.0 firmware version and on PC NanoVNA Saver 0.2.2-1 is running . A bit naively after calibration in the range 50 KHz - 60 MHz , I just connected output and input ports through a 10 MHz crystal to explore its characteristics, mainly serial R and Quality Factor . Graphical results seems fair but calculated value in nanoVNA Saver are a bit odd: Impedance = 55.32 - j3.7 ohm Quality factor: 0.067 In additon i tried to run from nanoVNA Saver an analysis handling the filter as a pass band and got this time a Quality factor: 54924.73 - a bit higher but anyway very far away from typical quartz Q. The corresponding bandwidth at -3dB was 1.82 KHz. Sorry was not able imbedding images in mail body, you can see them in the attached images.rtf file. Any hint is appreciated ? Stefano, I3VBP |
Re: Portable full 2-port 6 GHz VNA from YL3AKB
Reading this thread about market, sales, prices and specs.
I'm a radio amateur who appreciates good equipment. What I see at several radioclubs in the Netherlands (EU) is that the low priced nanoVNA is extremely popular. Most of the guys that buy them do antenna measurements or just want to explore this instrument (low cost), even if they own the good ol' MFJ antenna analyzer Only a few of those guys are interested in the world above 1 GHz. And for myself? HF man all the way. 80 or 90dB of dynamic range for working on the bandfilters? Wonderful and enough (better than my miniVNA). Have a good look at my antennas? Great! Smithchart? Need to have for me, but I spend a lot of time explaining the thing to fellow hams. They are mostly interested in SWR and sometimes will look at a bandfilter. It seems that the small nanoVNA-H has taken a big part of the hamradio-analyzermarket here (pricepoint under $50). The slower adaptors will probably choose an H-4 now. (My $0,02) Arie PA3A |
Re: Firmwares
Hello
The Output Multisynth Divider (OMD) in the Si5351A has a minimum division of 4, see the datasheet reg. 44 and +8 for the others. The use at 300 MHz, well above 200 MHz, is out of spec. But like many other components it will still work out of spec - but it depends. If we are only talking about a distinct output frequency the closer you get to 300 MHz the less certain you can be that it will work. Please see this message: /g/nanovna-users/message/3285 If I were to put my money on it I would say that the max fout is 280 MHz. If it works on 300 MHz I would say that it is a lucky punch. So 270 MHz is a safe and good S/N choice. Unless the sweep is very narrow I doubt there is a need for the OMDs to run in fractional mode. The two LOs have to track with the IF distance but even if they are a few Hz apart I don't think this will have any impact on the measurement. Here is a tutorial about the math in the Si5351A: Bo www.rudius.net/oz2m :: www.rfzero.net |
Re: Issue with nanoVNA-Saver in at least the last several versions.
Did I miss anything?Yes, you posted this in the wrong group. Instead, try one of these: /g/nanovna-users/wiki/home#nanoVNA-F |
Re: Issue with nanoVNA-Saver
#nanovna-saver
Hi Bryan,
thanks for pinging me - I'll get on it as soon as things quiet down a little more here at work. Should be able to look at it later today or tomorrow :-) -- Rune / 5Q5R On Thu, 6 Feb 2020 at 06:41, Bryan, WA5VAH via Groups.Io <bryburns= [email protected]> wrote: Rune, |
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