Re: USB connection failed
Hello,
Since this morning, my NanoVNA-H don't accept the USB connection.
I tried on 3 different PCs, no success.
On battery, all is ok but i'm not able to do charging.
I suspect an USB interface failure but i'm not sure...
What can i do ?
Thank you for your help.
Rudi
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Let's hope it's just dust or dirt in the connector, perhaps remove with a brush. Or, the connector may have broken off the board enough to have dropped one connection - physical problem rather than anything more complicated. Tale a look.
Cheers,
David
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Web:
Email: david-taylor@...
Twitter: @gm8arv
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Hello,
Since this morning, my NanoVNA-H don't accept the USB connection.
I tried on 3 different PCs, no success.
On battery, all is ok but i'm not able to do charging.
I suspect an USB interface failure but i'm not sure...
What can i do ?
Thank you for your help.
Rudi
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Re: Is Gen11.TAOBAO nanoVNA upgradeable to 1.5GHz
Hello Bert,
There is a schematic from the H4 design version 4.2.1 from 2020-02-13 which is the last version, see:
Unfortunately in the schematic the printed year is 2019, but it is from 2020.
Then the replace list is (SMD size 0603):
- remove R29, R30 and R31
- replace R13 by 0 Ohm
- replace R9 by 200 Ohm
- replace R24 by 56 Ohm
- replace R22, R23 by 51 Ohm
- replace R25 by 51 Ohm
- add a 100 nF capacitor parallel to C40, C42, C44 (SMD 0603)
Additional calibration with the software nanoVNA-saver (version 2.2) with 4 segments (404 points) and average of 4 will bring a few dB better values,
if you calibrate from 50 KHz to 1300 MHz (especially for THROUGH).
73, Rudi DL5FA
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Optimizing the S11 of a pre amp usually doesn't result in best noise figures and hence best overall receiver sensitivity. Also having too much gain in a pre amp may cause overload and intermodulation.distortion in the receive system. When my job was designing add on VHF pre amps, we aimed for closer to 12 dB gain.
Also, CH0 has a relatively strong output and connecting directly to the pre amp input could cause the output to be very high, possibly pushing it to compression, causing false gain readings and making the bandwidth spread wider than it really is.
I would put 20 - 30 dB between CH0 and the input and connect the output directly to CH1.
But this discussion has made me wonder if there is a way to use a VNA for noise figure optimization.
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Re: Integration of a nanoVNA unit into an antenna system as indicator of resonance frequency
Following up on this thread 6 months later. Does anyone know if there has been any firmware development performed on a function to track the lowest SWR for the nanoVNA?
John - W3JED
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I hadn't seen much written about using the NanoVNA with VHF preamps. I have
a couple I have never adjusted except "by ear." So I thought I'd give it a
try.
I put a 20 dB attenuator on the output, since the estimated gain for the
two preamps was around 20 dB. I fed the input directly from the port 0 of
the NanoVNA so I could look at s11
My 432 MHz preamp needed some peaking. It wasn't difficult. I got it tuned
so s11 is -45 dB and the gain is about 21 dB. That's as I expected. Not bad
for a 20 year old preamp using an ATF10136.
My 222 MHz preamp uses the same FET and circuit. It did not look so good. I
could only tune the s11 to about -6 dB and the output did not peak anywhere
throughout the tuning range. Gain shows th be about 6.5 dB. There is
definitely something wrong with the preamp. I have also been using it for
20 years. I knew it has gain but it never did seem to have as much as my
144 and 432 MHz preamps. Now I've verified this. I suspect some value
(probably the input tuning inductor) is off.
I can't do anything for noise figure with the NanoVNA but at least I have
the 432 MHz preamp tuned pretty close. I can get the preamps checked and
tuned at a VHF conference next year.
73, Zack W9SZ
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Get the NanoVNA H4 with the 4 inch screen. You will be much happier. I got mine from R&L Electronics.
Sam
W3OHM
P.S. You probably won't touch the MFJ once you have the NanoVNA
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Re: V2 aliexpress sellers
Hi Gabriel, I have bought H4 from eTool Store on Ali. Pls, what can tell me about it ? Can you? Just for my curiosity. Thanks, Milo? ---------- P?vodn¨ª e-mail ---------- Od: Gabriel Tenma White <OwOwOwOwO123@...> Komu: [email protected]Datum: 18. 6. 2020 19:08:17 P?edm¨§t: Re: [nanovna-users] V2 aliexpress sellers "A new review posted on an Aliexpress listings reads "The device is original, which was confirmed by the developer." I don't remember confirming any device as original. That store used to get their V2s from shengxun, but switched to selling clones some time ago. If you really want to be sure you can always PM me before buying. Most clones of the V2 now perform ok, but consider buying from the Tindie store/nanorfe if you want to support the original developers (only these two stores remit a percentage of profit to the developers). "
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Thanks for the tip on using Automator. I¡¯ve had this Macbook Pro for 5 years now and never even looked at it. I will certainly look at it now. I think I may not have jumped to using it becuase I am so comfortable using a terminal on so many different OSes that I never gave it a thought!
-rick
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On Jun 18, 2020, at 07:22, warnergt via groups.io <warnergt@...> wrote:
I installed nanovna-saver-0.2.2 on my Mac and it works perfectly in MacOS (I use the latest Catalina 10.15.5).
I wish I could remember exactly how I installed it.
I do know that I can invoke it from a terminal command line with: NanoVNASaver
Then, I created a simple script to run it:
##!/bin/bash
NanoVNASaver
Then, I used Apple's Automator to create what looks like and app to run that script.
Thus, NanoVNASaver looks like a regular app on my Mac. I simply double-click on the icon and it starts up.
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Thank you all for sharing your information. Time to make a purchase and move forward. More questions may follow.
73,
W9OD
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I don't think any nanovna "V1" can work with good accuracy above 900 Mhz,
whatever "flavor". For all my measurements above 300 Mhz, I use another VNA
offering a much better dynamic range.
A nanovna "V2" is what is needed to work above 900 Mhz not a "V1"
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On Mon, Jun 15, 2020 at 2:10 PM <iyerak@...> wrote: Hi! I'm new to this group and just received my NanoVNA-H. I discovered
some issues, and would appreciate the advice of members in this group on
the following four questions. Thanks in advance!
1. A full calibration to the end of the supplied cables and up to the
maximum frequency of 1.5GHz gave me good results when I connected the
short/open (S11~0dB) and load (S11~-50dB) standards to ch0. However, when I
connected the thru standard, S11 was between 15-20dB at most. This sounds
really poor, given that the thru is supposed to be a matched 50-ohm
connector.
2. Measurement of a microstrip double-stub bandstop filter at 1GHz showed
an S21 curve that unnaturally flattens out at about -20dB from
approximately 900MHz to 1.1GHz, rather than dipping down to about -50dB,
which is what full-sized VNAs show.
3. All my measurements show something weird around 900MHz, like a
discontinuity in the curves. I know that the NanoVNA-H switches over to the
3rd harmonic from 900MHz to 1.5GHz and the dynamic range is reduced, but
why shouldn't the curves be continuous?
4. Finally, just a question: has anyone had luck finding the properties
(e.g. capacitances, inductances, phase offsets, etc.) of the supplied
calibration standards, so that they can be entered into NanoVNA-saver?
Thank you!
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I export the nanovna touchstone files into simsmith where I can make different simulations/adaptations On Wed, May 27, 2020 at 4:28 PM warnergt via groups.io <warnergt= [email protected]> wrote: I used to use Touchstone many, many years ago. It was a great program.
I haven't worked with S parameters for a long time so I'm out of touch
with the currently available applications.
What current applications work like Touchstone and/or work with Touchstone
files?
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I had completely forgotten about Les Besser.
He was great -- and one really smart guy.
I met him somewhere -- perhaps at one of the
microwaves courses he used to teach.
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I installed nanovna-saver-0.2.2 on my Mac and it works perfectly in MacOS (I use the latest Catalina 10.15.5).
I wish I could remember exactly how I installed it.
I do know that I can invoke it from a terminal command line with: NanoVNASaver
Then, I created a simple script to run it:
##!/bin/bash
NanoVNASaver
Then, I used Apple's Automator to create what looks like and app to run that script.
Thus, NanoVNASaver looks like a regular app on my Mac. I simply double-click on the icon and it starts up.
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I am a newbie to the NanoVNA H4 as well, and will defer to others that are more knowledgeable on this topic than me, but I read on another forum that RigExpert release AntScope2, an open source product () where some were using AntScope2 with their NanoVNA devices. This may or may not be an option for Mac users.
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Hi Craig,
Yes, i used it today actually with a NanoVNA-H and NanoVNA-Saver on OSX
Mojave, no trouble.
It's certainly easier to use on the computer, but if you'll be hanging off
towers and prefer to read the screen directly, then the 4" screen-size
might be a better buy (or for failing eyes) :)
There is also an Android app that might make the above easier although i
haven't tried it myself yet.
But it gets the job done. Which is better is debatable, the NanoVNA is
certainly cheaper.
Hope it helps...
Cheers,
Chris.
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On Thu, Jun 18, 2020 at 10:01 AM Craig Taylor <cstaylorod@...> wrote: I am thinking about getting a nanovna, is the Mac operating system usable
with them.
I am expecting to use it in place of my MFJ 259A. Will it be everything I
wish it would be?
If I get a heads up here, please be patient with me.
73,
Craig W9OD
Happy is the nation whose God is the Lord.Ps 33:12
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On Wed, Jun 17, 2020 at 01:20 PM, Erik Kaashoek wrote:
The differential input resistance of the SA612 is about 3kOhm.
Ok, I thought that he wanted to measure the CH1 termination resistors network, that is why I mentioned "nanoVNA switched off of course". Instead from what I understand he wanted a live ohmmeter measurement, whereas obviously that is not proper.
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Hi Craig,
you may want to install Python on your machine now so you can try out the nanovna saver. He gets acquainted with it until the nanovna arrives. Rick included a pdf on how to install it.
You may also want to check out the forum wiki and files. Since this is a large amount of material, I suggest that whatever topic interests you read it.
73, Gyula HA3HZ
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*** If you are not part of the solution, then you are the problem. ( ) ***
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Please note that the build date for 4.2.1 is incorrectly 2019, correct 2020.
--
*** If you are not part of the solution, then you are the problem. ( ) ***
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On Wed, Jun 17, 2020 at 05:39 PM, <iyerak@...> wrote:
Just found this:
It looks like an acknowledged design error!
It looks that it could be resolved with the v4.2.1 Compare this with this changed the CH1 50Ohm network.
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David J Taylor
Sam Reaves
Gyula Molnar