Re: Wish list of future features for nanovna
NanoVNA can`t change output (only 4 steps), also output depend from frequency
PS yes possible use external attenuator controlled by NanVNA over Serial, calibrate it. For this need software update (this also depend from Attenuator use)
PSS you can use TinySA for this
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Re: Measuring swr on fan dipole or windom antenna
On Fri, Jun 9, 2023 at 12:29 AM, Steve Johnson wrote:
When using a NanoVNA to measure SWR on a multi-element antenna, with different
length elements but all fed from the same feedpoint, which element¡¯s swr is
the Nanvna displaying data for?
What are your START and STOP frequency settings? On which bands is the antenna supposed to work? When I sweep a multiband antenna, the nanovna shows me the SWRs of all the resonances within the range of the sweep. I have preset scan choices for 1.5 to 30 MHz and for 3.0 to 30 MHz sweeps, and it works very well. I see all the resonances on that one sweep setting. The Nano will only show you what you actually tell it that you want to see. -- Doug, K8RFT
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Wish list of future features for nanovna
Guys/gals,
I bought my nanovna H over a year ago and for such a small price, it is an amazing bit of kit.
Besides antenna tuning I use it for genera tuning of my rigs. I use it as a signal generator for RX alignment purposes. The nanovana whacks out a strong signal for alignment purposes and I use my homebrew signal reducer in order to carry out RX alignment purposes.
My issue is the output of the signal generator is unnknown and it would be a useful feature at some future stage if 'namovna calibrated' signal outputs were incorporated into its general design. I do not have much tuning equipment, none of it is calibrated and I am simply looking for a cheap and easy means to tune my antennas and rigs without turning my shack into an RF lab!
To everyone involved in the design, development and implementation of these devices, you have done an amazing job because you have made cheap access to a suite of analytical tools we could only dream of 50 years ago.
Ellis (G1PDA)
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Re: Whats the best way to test your NanoVNA H4
#nanovna-h4
No, the nanovna has its own internal signal generator, and wouldn't work with an external one. The best way to check it is to calibrate it (calibration reset, then open, short, load calibration). Then in normal trace mode, displaying the smith chart, attach the same calibration standards one at a time and verify that the short puts a dot at the left of the display, the load in the center, and the open at the right. If this works, your nano should work fine to show your antenna performance, like the SWR trace. See the "Absolute Beginners Guide" in the files section of this group: /g/nanovna-users/files/Absolute%20Beginner%20Guide%20to%20The%20NanoVNA/Absolute_Beginner_Guide_NanoVNA_v1_6.pdfIf the calibration doesn't work, then we have more troubleshooting to do.
On Sat, Jun 17, 2023 at 4:22?PM Muggs KC3UDZ <Muggs828@...> wrote: Hello All,
My NanoVNA H4 is gone completely goofy. I cannot get a good reading from
it on a known good antenna.
What would be the best way to test it for proper function? Can I take a
reading from a signal generator set to something like 500KHz?
TIA,
Muggs KC3UDZ
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Hello All,
My NanoVNA H4 is gone completely goofy. I cannot get a good reading from it on a known good antenna.
What would be the best way to test it for proper function? Can I take a reading from a signal generator set to something like 500KHz?
TIA,
Muggs KC3UDZ
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Ok so the MS5351 was already chosen but then the threshold was at 300.001M and once reduced to 290M and calibrated 50K to 1.5G the anomaly is not as bad as it was. I still see a S11 logmag bump at 300.040M with the short and open then infinite SWR / logmag between 285M - 319M with the load.
Thanks for your time!!!
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My fw use si5351 generator (used on old board revisions) as default settings, last hardware have - MS5351
Need switch in:
Config->Expert Settings->More->Mode to MS5351
Additional possible need change Threshold value (I use 300.001M as default for most Si5351 generators)
Config->Expert Settings->Threshold to 290M
After save config
Config->Save
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Ok so I bought a NanoVNA-H 4 from R&L. It came with ver. 1.2.14, I installed DisLord¡¯s Ver. 1.2.20.
Now before I did this I played with the original version and everything seemed ok. Then installing DiLord¡¯s version gives me either a software anomaly or has pointed out a flaw in the analyzer and I would like to find out which.
After calibration (50k to 900M) I see some really crazy stuff starting at about 299.912MHz and shows ¡°heavy hash¡± (where everything just goes nutz! Kinda like a baby with it¡¯s first try with paper and a crayon¡ VERY messy!!) that continues up to about 306MHz then settles down a bit for the rest of the spectrum - still not as flat as prior to 300Mhz.
I¡¯ve tried some earlier versions from DiLord and all do the same (leading me to believe it¡¯s not either but just these two are not good for one another?).
Because I¡¯ve gone ahead and installed hugen79¡¯s ¡°Synchronize DiSlord's version 1.2.14 code¡± which I believe is what came on it in the first place and I do not have this issue.
So, is this a thing or am I just ¡°________________¡± (enter anything that suits you here)¡.
Any explanation?
Thanks
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Re: Measuring swr on fan dipole or windom antenna
If the antenna has wires tuned for several bands, the NanoVNA will display the SWR over a specified spectrum, and whichever wire is tuned to a particular band will cause a lower SWR at that frequency. Your regular SWR meter will show the same thing. Most of these antennas use wire lengths that are harmonically related. The wires do interact, but say you have an 80-40-20-15-10 meter fan dipole. You're going to see a dip on the wire for a particular band. Zack W9SZ On Thu, Jun 8, 2023 at 11:29?PM Steve Johnson <cascadianroot@...> wrote: When using a NanoVNA to measure SWR on a multi-element antenna, with
different length elements but all fed from the same feedpoint, which
element¡¯s swr is the Nanvna displaying data for?
<> Virus-free.www.avast.com <> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
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Re: Measuring swr on fan dipole or windom antenna
Where does the original poster say anything about the "measure cable:"
function? The NanoVNA has an "SWR" function. I use it quite a bit.
Zack W9SZ
<>
Virus-free.www.avast.com
<>
<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
toggle quoted message
Show quoted text
On Fri, Jun 16, 2023 at 8:40?PM Stan Dye <standye@...> wrote: The "measure cable" function was designed to measure a transmission line
(e.g. length of coax), open at the far end, and give you its characteristic
impedance, loss, and length (length only when you give it the correct
velocity factor for the cable). It does this by finding the 1/4 wave
resonant frequency for the full length of cable, and doing the
calculations, assuming it is a transmission line. If instead you have a
wire antenna at the end, or a multi-wire fan dipole attached at the end,
there may be multiple 1/4 wavelength resonance points - it always chooses
the first, so it will only show you one length. The first one it sees may
be of the length of the coax, or it may be of the coax plus one of your
wires, depending on the design of your system. If you instead use the TDR
function, you may be able to see peaks due to reflections from the
feedpoint and each of the wires, but maybe not: if the antenna is closely
matched in impedance, it won't give much of a reflection to see. I've
never tried that - it may be interesting to see what happens.
On Fri, Jun 16, 2023 at 5:53?PM Gary W9TD <w9td@...> wrote:
Steve,
The nano is measuring only the cable length, not the antenna plus cable.
Gary
W9TD
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Re: Measuring swr on fan dipole or windom antenna
On 6/17/23 5:31 AM, DougVL wrote: On Fri, Jun 16, 2023 at 08:48 PM, Steve Johnson wrote:
I would expect it to show the length of the wire segment being used (i.e.
lowest SWR) at a given frequency
BUT with the 'measure cable' function, you cannot specify a frequency, and the function is not intended or designed to measure frequency (it sends a pulse, not a sweep) or measure SWR. it does not send a pulse - what it does is sweep a range of frequencies, and then mathematically transforms the measurement to what it would have been if it were a pulse (or step). MEASURE CABLE measures cable length, impedance and loss.
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Re: Measuring swr on fan dipole or windom antenna
On Fri, Jun 16, 2023 at 08:48 PM, Steve Johnson wrote:
I would expect it to show the length of the wire segment being used (i.e.
lowest SWR) at a given frequency
BUT with the 'measure cable' function, you cannot specify a frequency, and the function is not intended or designed to measure frequency (it sends a pulse, not a sweep) or measure SWR. MEASURE CABLE measures cable length, impedance and loss. -- Doug, K8RFT
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Re: Measuring switch isolation Re: [nanovna-users] Connect VNA thru tuner to antenna
On Fri, Jun 16, 2023 at 07:51 AM, Jim Lux wrote:
typically quite frequency dependent for switches
This is true of most switch topologies. Another frequency-dependent characteristic of mechanical switches which can crop up during testing, especially in the microwave region, is resonances from unterminated switch ports. Always terminate all unconnected ports when trying to measure switches. 73, Don N2VGU.
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Re: Measuring swr on fan dipole or windom antenna
Otherwise the cable
measurement function makes no sense. ** Yes, it is used to measure the length of a real cable :). In your case, you are not measuring a cable but an antenna connected to the end of a cable. When only one port is used, the nanoVNA only knows how to measure impedance versus frequency. Then, it is through calculations, that we make an interpretation. 73 -- F1AMM Fran?ois De la part de Steve Johnson Envoy¨¦ : samedi 17 juin 2023 02:49
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Re: Measuring swr on fan dipole or windom antenna
The "measure cable" function was designed to measure a transmission line
(e.g. length of coax), open at the far end, and give you its characteristic
impedance, loss, and length (length only when you give it the correct
velocity factor for the cable). It does this by finding the 1/4 wave
resonant frequency for the full length of cable, and doing the
calculations, assuming it is a transmission line. If instead you have a
wire antenna at the end, or a multi-wire fan dipole attached at the end,
there may be multiple 1/4 wavelength resonance points - it always chooses
the first, so it will only show you one length. The first one it sees may
be of the length of the coax, or it may be of the coax plus one of your
wires, depending on the design of your system. If you instead use the TDR
function, you may be able to see peaks due to reflections from the
feedpoint and each of the wires, but maybe not: if the antenna is closely
matched in impedance, it won't give much of a reflection to see. I've
never tried that - it may be interesting to see what happens.
toggle quoted message
Show quoted text
On Fri, Jun 16, 2023 at 5:53?PM Gary W9TD <w9td@...> wrote: Steve,
The nano is measuring only the cable length, not the antenna plus cable.
Gary
W9TD
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Re: Measuring swr on fan dipole or windom antenna
Steve,
The nano is measuring only the cable length, not the antenna plus cable.
Gary
W9TD
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Re: Measuring swr on fan dipole or windom antenna
My NanoVNA shows a single wire length (when measuring cable) for the fan dipole even though there are definitely multiple lengths of wire (all different) in the air. This length stays the same as I roll down the frequency range. I would expect it to show the length of the wire segment being used (i.e. lowest SWR) at a given frequency. Otherwise the cable measurement function makes no sense.
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What DFU software are you using? There are four programs for installing
firmware updates that I know about.
The original one from ST, Dfuse Demo, works well on older computers but
refuses to connect on many newer ones. The symptom is that it never sees
your device. (It's likely some sort of timing issue that makes it
incompatible with some USB controllers.) Sometimes it can be made to work
by switching to another USB port (try a USB 2.0 port if your system has
one), or by inserting a USB hub between the computer and your nanoVNA. ST
no longer supports that software so it won't get fixed.
Its replacement, STM32CubeProgrammer, works well on those newer computers
but is too big to run well on some older ones. An interesting gotcha is
that it requires .BIN files, while Dfuse uses the .DFU file format. Current
nanoVNA firmware can be downloaded in both formats; make sure to get the
one you need. (Older ones were only provided as .DFU files.) There is a
utility provided with Dfuse Demo that will convert between the formats; you
may want to install that even if you use STM32CubeProgrammer.
The final option is open source tools; dfu-tool and dfu-util are out there,
may be included with your Linux distribution if you run that OS, and
versions are also available for Windows and macOS. I have no personal
experience with them.
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On Fri, Jun 16, 2023 at 9:20?AM Muggs KC3UDZ <Muggs828@...> wrote: Hello All,
I cannot for some reason get my H4 into DFU mode on my laptop; I don't
have a problem with my desktop computer (running the same version of
NanoVNA App).
Is there something that I should be looking for to remedy this?
BTW, I know the answer is move it to the desktop for firmware updates, but
I'm curios why it's not being found on my laptop.
TIA,
Muggs
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Hello All,
I cannot for some reason get my H4 into DFU mode on my laptop; I don't have a problem with my desktop computer (running the same version of NanoVNA App).
Is there something that I should be looking for to remedy this?
BTW, I know the answer is move it to the desktop for firmware updates, but I'm curios why it's not being found on my laptop.
TIA,
Muggs
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Re: Measuring switch isolation Re: [nanovna-users] Connect VNA thru tuner to antenna
On 6/16/23 4:33 AM, Bryan Curl wrote: Thanks Jim.
Still learning this neat tool.
So just the phase trace is all thats needed on s21 to measure isolation?
Are results frequency dependent?
Bryan, n0luf
Log mag S21 is what I use, and yes, typically quite frequency dependent for switches based on non-RF relays (i.e. most amateur switch boxes). The leakage is mostly due to parasitic C, so the leakage is bigger (worse) at higher frequencies.
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Muggs KC3UDZ
Dentron
Donald S Brant Jr
Gary W9TD
Shirley Dulcey KE1L