Re: How to make nanoVNA "bulletproof" ?
I cut a piece of 1/4 inch plexiglass about 9 inches x 6 put Velcro on the nanovna and cables . It keeps the cables from damaging the connectors. De K8HTB
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Re: How to make nanoVNA "bulletproof" ?
I have been using VNAs at work since the '80s. Professional "box" VNAs have extensive internal power supply and data line decoupling/shielding and are designed as a system with their PC/controllers/display, all housed in a heavy metal EMI-shielded enclosure where all ingresses are carefully filtered, with a chassis grounded via power cord.
The pro USB-based VNAs (Copper Mountain make outstanding units) usually come in a stout shielded housing and generally have a ferrite (or one on each end) molded into the provided heavy and presumably well-shielded USB cable and the user is cautioned to use that cable only.
Quite a different situation from an inexpensive handheld device which communicates with and is powered by a skinny $1cable that doubles as a dandy RF pickup antenna going into a random poorly-grounded or ungrounded laptop or charger with unknown USB power quality. So it is not unreasonable to expect to have to do some RF decoupling work when using these amazing little instruments, especially when measuring antennas.
They may have their issues but just step back and think of what your $50 or $100 buys; they can do 95% of the work that the multi-$100K Keysight ones do.
73, Don N2VGU
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Re: How to make nanoVNA "bulletproof" ?
On 6/8/22 9:58 PM, Martin Glazer wrote: For the professional VNA analysers, Do they put atorroid chokes on those?
I was wondering. That would depend on the test setup.? Most people, when measuring an antenna, use chokes and/or baluns at various points. In a anechoic chamber situation, like when doing a near field scan (which uses a VNA as the measurement instrument) you'd make sure the feed lines are not coupled to the antenna, and chokes are a typical way to do that. In the field, with something like a Keysight Fieldfox, it kind of depends. If I'm measuring a dish antenna and its feedlines, I might not use any choke at the VNA - the feedline is sufficiently decoupled.? Measuring something like a dipole, you bet I'd use a bunch of toroids and clamp on ferrites. What you typically do is make the measurement without, then add some and see if it changes. If it changed, then try adding some more and see if it changes again. In extreme cases, one goes to remote or programmed operation and putting the test equipment in a box with a small computer to drive it. Right now, I'm trying to figure out how to measure the 4 port impedance of a pair of deployable dipoles, and shoehorn everything into a metal box that represents the structure to which the dipole is attached.
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In latest fw v 1.2 there is an option to Save Calibration and to Save Configuration.
Moreover, the Calibration (within a frequency range) could be saved into a "Slot" (you have 7 slots for Save/Recall_0..6 in nanovna handy, where the slot is stored in the free rom flash on the mcu chip), or, you could save the Calibration on the SDcard (when available).
You can then "load" the calibration or the config with "Load Calibration" or "Load Config".
I discussed that a couple days back with Dislord on his github, as I was not sure how the Save/Load Calibration actually works.
You may store almost unlimited number of Calibration "slots" under a "file name" on your SDcard (each slot file is 16kB large), and then to replace a specific Slot in your nanovna with that configuration anytime. That require a sequence of steps, however.
Mind you will save only a single "currently active slot" on the SDcard under a name you like (you do not store all 7 slots).
I have, for example, about a dozen of various calibration slots saved on my SDcard and I can Load one of them into any of my slots in nanovna as I need them.
To describe Saving/Loading Calibration slots in detail would be a good enhancement of the user manual, as it is a pretty useful feature, and mastering it would definitely help you when working in the field.
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Sorry I thought I had given the link, here it is: Op di 7 jun. 2022 om 18:31 schreef Roger Need via groups.io <sailtamarack= [email protected]>:
On Tue, Jun 7, 2022 at 07:03 AM, Victor Reijs wrote:
Here is the Zsource I derived (using the method of Owen Duffy). I used
one
100ohm SMD resistor (99ohm using DVM) soldered between two female SMA PCB
connectors: Could you please provide a link to the "Duffy method" of determining
Zsource?
Roger
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Re: How to make nanoVNA "bulletproof" ?
For the professional VNA analysers, Do they put atorroid chokes on those? I was wondering. Martin N6QlH On Wed, Jun 8, 2022 at 7:08 PM Clyde Lambert <clyde.lambert@...> wrote: There is always Velcro. I use sticky back Velcro to attach devices to a
serface. That way if I want to move it to somewhere else, I just separate
it and move on.
Clyde KC7BJE
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CONFIG->SAVE
Save device settings from config (like touch calibration, threshold, vbat_offset, colors)
CALIBRATION->SAVE X
Save calibration and trace/marker settings
After calibration if use DONE, device ask SAVE data to any slot (you can skip this)
DONE IN RAM just apply calibration (not ask about save, but you can save it after by CALIBRATION->SAVE)
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P. S.
It has the SD card connector installed. I also just easily installed a Bluetooth module.
Super nice 4 inch screen.
Clyde
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Hi,
I just purchased a new NanoVNA H4
Version 4.3, from R&L Electronics in Ohio U. S. .
They are on of the best recommended outlets.
Clyde Lambert KC7BJE
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Re: How to make nanoVNA "bulletproof" ?
There is always Velcro. I use sticky back Velcro to attach devices to a serface. That way if I want to move it to somewhere else, I just separate it and move on.
Clyde KC7BJE
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White screen on NanoVNA SAA-2N
Following is a new topic post I tried on the NanoVNA V2 users group. (I got a message on the Messages page which said that it would be reviewed by moderators, but it hasn't showed up yet.) So I'll try here also:
"Although this discussion is a bit old I thought I'd give it a try, mostly because my SAA-2N has the same page on Config view: 20200617 and 1a9a11d. While trying to update my firmware, as I moved the usb plug from Win 10 machine to an iOS machine, the screen went white and has not returned. Does this sound familiar? I've tried every combination of screen taps, button pushes, on-off switch and cannot get back to any normal page. I opened up the case to see if the screen ribbon connector had come loose again but it was fine. No components seemed fried, looked like new. Is there a reset button ir procedure that anyone knows about? Yes, it is a clone but a highly recommended one - I hope I didn't fry it! tnks!
72/73 de k1qed, bob.c qrp 4evr!"
Anyone have any good ideas? tnks! bob.c
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Re: Off subject - nanoVNA forum no longer on Facebook
#nanovna
Hello,
I just did a search on facebook using
"NanoVNA,TinySA"
As a surch heading and found the group you are refering to.
Do not use "NanoVNA and TinySA"
Clyde Lambert KC7BJE
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Re: Off subject - nanoVNA forum no longer on Facebook
#nanovna
Last year this person posted to the group and was the cause of some disruption. I think they were kindly requested to go elsewhere.
Gary
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At 08:34 PM 6/8/2022, you wrote: On Wed, Jun 8, 2022 at 05:04 PM, Anne Ranch wrote:
This is an official name of the forum
NanoVNA and TinySA - Facebook
This group is active and has 7310 members. I searched for your name "Anne Ranch" and do not see you listed as a member. I am active in this group and do not recall any posts from you.
Roger
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great post
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On Wed, Jun 8, 2022 at 4:32 PM Anne Ranch <anneranch2442@...> wrote: Let me restate - I have been actively using nanoVNA for about two weeks -
and I am a certified engineer and real engineers do not read manuals...
Consequently I make mistakes , because I only read
what I IMMEDIATELY need...
With that said - I find the wast variety of "menu flowcharts " .
disgusting.
It looks as the primary goal was to cram everything in minimal space...
What happen to real (IBM) style flowcharts ?
GUI ( graphical USER interface ) Pitiful.
Any nanoVNA " coders " ever hear about "tool tips " ?
How about " document header(s) " levels?
In my years of gainful employment I did "(graphical) user experience "
quality control...
(some "coders" did not like me ...)
and if anybody is going to say " what do you expect for free ..."
I AM DONE HERE
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Re: Off subject - nanoVNA forum no longer on Facebook
#nanovna
On Wed, Jun 8, 2022 at 05:04 PM, Anne Ranch wrote:
This is an official name of the forum
NanoVNA and TinySA - Facebook
This group is active and has 7310 members. I searched for your name "Anne Ranch" and do not see you listed as a member. I am active in this group and do not recall any posts from you. Roger
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...and one wonders why a person might be removed from a FB group.
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How to make nanoVNA "bulletproof" ?
Little over statement in the title , but ...
Again - started using the nanoVNA , to tune antenna, about two weeks ago and
1. it is HOT in Huston and impossible to read the display in direct sun
2. after "transmission line theory " is dutifully applied - the "portable "
miniature analyzer looses its both advantages as "miniature " and "portable".
3. it is better to keep USB connected and keep battery alive
4. after I get nanoVNA-saver to behave I won't need the display anyway
5. in future I may add "calibration switch"....
actually it is of great disadvantage
hanging on USB cable and on pretty stiff end of RG6 ( that what I have to work with ...)
I do not want fancy "enclosure " and I an not stupid to break the SMA connectors -
I need to nail the nanoVNA to the top of my desk !
...more overstatement ...
Seriously - I have what used to be antenna rotator aluminum plate , about 1/4 inch thick
I can cut to size of nanoVNA , add some " rubber feet" ...
Would that work ?
Open to ideas ... no Altoids boxes , please...
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If you want to come back where you last were, and no memory 0, on the later firmware(s) there is an advanced option "maintain state" that will cause the device to power back on exactly as it was powered off.
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On June 8, 2022 3:05:36 PM CDT, Anne Ranch <anneranch2442@...> wrote: Rich, what is really puzzling - assuming that the original intent of father of "nanpXXXX" was to make money - why is internet full of
"wannabe" experts publishing and mostly copying stuff with little regards to facts?
After I par6tially read one of the "beginners guide" I did same as you did - made a copy of published document and started annotating it....
PS
As far as "SAVE" goes - I am sure I was "doing it wrong" , but after pushing "DONE" I got an option to "SAVE 0 thru 3 ".
Now if I can repeat that process every time, I'll be a happy camper...
PPS
It still looks that after cycling power - SAVE 0 is "loaded" as default....
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
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Let me restate - I have been actively using nanoVNA for about two weeks -
and I am a certified engineer and real engineers do not read manuals...
Consequently I make mistakes , because I only read
what I IMMEDIATELY need...
With that said - I find the wast variety of "menu flowcharts " .
disgusting.
It looks as the primary goal was to cram everything in minimal space...
What happen to real (IBM) style flowcharts ?
GUI ( graphical USER interface ) Pitiful.
Any nanoVNA " coders " ever hear about "tool tips " ?
How about " document header(s) " levels?
In my years of gainful employment I did "(graphical) user experience " quality control...
(some "coders" did not like me ...)
and if anybody is going to say " what do you expect for free ..."
I AM DONE HERE
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Donald S Brant Jr
Martin Glazer
Clyde Lambert
Roger Need
Larry McElhiney