NanoVNA V2 aka S-A-A-2

[cdev]

I don't think V2-Plus is such a good name. Also, V2-N may be N now, but at some point there will be a newer N. I think you could probably think of a much better name.  You could have a numerical name that gives the most important specs, and a model name that has a kind of fun or endearing quality - which is unique. Try to think of some cultural name - maybe a character for a TV soap opera or manga or mythology you all like (if there is such a thing)  ?

bla bla bla.. Or at least thats what I think.

I totally know what you mean about a metal case sometimes causing problems. I am dealing with that right now with a LNA that I am trying to put into a nicer metal box. Its hard to get it right, where the box really makes a big improvement instead of making issues like unwanted USB-originating noise worse..  Because so many cases now have an anodized outer metal shell, (which doesnt conduct electricity!) they are really crap. The ones that look semi decent are more often than not crap. Here is what I am trying to do. Put a picece of copper - not coppper tape, on the inside to be the actual grounded thing. A c shaped piece of copper that connects to everything as if it was the case. It doesnt have to enclose it completely, the outer case is for the looks. And it conducts inside. Just not on its surface. The [iece of copper flashing is simply to create a common ground point thats very low impedance, between the two connectors (and the USB) thats  not the PCB.

That works with an LNA.

I need every bit of help I can get with my local RF noise.

Gradually the noise where I live has just been getting worse and worse. Some of it is not coming from here so its very hard to get rid of. I need to get a small radio and literally hunt its source down.



Try using a piece of metal to see if that makes the metal case work acceptably well. The two horns they have on that other case are nice to protect the connectors. They are likely trying to sell below their cost.

I have now prototypes of the 4 inch version with 400 points/s sweep rate. The noise floor stays at around -80dB up to 1.5GHz even with the faster sweep. The DSP code can go up to 500 points/s but the UI fresh almost doesn't keep up when the 4 inch display is used, so it'll have to be 400 points/s.

V2-N will be renamed to V2 Plus to avoid confusion with another NanoVNA variant. I think it'll be available in a week or two. The improvements are 200 points/s sweep (compared to 100 points/s for the current V2) and a bit lower noise floor.

The 3D enclosure and battery option will also be available in a week or two, maybe a bit earlier than the V2 Plus.

[joeqsmith]

I have now prototypes of the 4 inch version with 400 points/s sweep rate. The noise floor stays at around -80dB up to 1.5GHz even with the faster sweep. The DSP code can go up to 500 points/s but the UI fresh almost doesn't keep up when the 4 inch display is used, so it'll have to be 400 points/s.

V2-N will be renamed to V2 Plus to avoid confusion with another NanoVNA variant. I think it'll be available in a week or two. The improvements are 200 points/s sweep (compared to 100 points/s for the current V2) and a bit lower noise floor.

The 3D enclosure and battery option will also be available in a week or two, maybe a bit earlier than the V2 Plus.

Very nice.  For headless, can you get the data across the USB fast enough to run 500pps?   

[OwO]

Are you referring to ch_scr's case, post #2 of this thread?

Yes

For headless, can you get the data across the USB fast enough to run 500pps?   

Should be doable, but it's a bit more noisy at 500 points/s.

I think V2 Plus is a good name, there was "miniVNA Tiny plus" and "miniVNA Tiny plus2"

[0culus]

Definitely gonna keep my eye on the store...of course it comes out right after I got a standard V2. 

[OwO]

Yeah, the reason we have to push out a new design so fast is because others have started selling our V2 design at extremely thin margins and with fancier packaging. HCXQS had not even 6 months to sell the V2 before getting overtaken by clones. They are the only manufacturer supporting the developers, so please help us and keep reminding people that only HCXQS on Tindie is the official manufacturer and supports the original developers. We had to move to a new groups.io forum because the admins on the old nanovna-v2 forum (none of HCXQS people or I are admins, go figure) keep promoting a clone as if they are official.

New support group is here: https://groups.io/g/NanoVNAV2

[thinkfat]

When you have the new 4" design ready, I'll certainly buy from the tindie store. Just make sure they have stock I only bought from Aliexpress because of that, but I made sure to check with you beforehand which store sells original equipment.

[avlijas.sladjan]

Hi. I received V2, and it worked perfectly. I hope that mine is original, not clone (I will love to support real developer).
Before V2, I was working on my version of VNA (to have a small VNA for 25M-4G, together with nanoVNA v1), and make a v0.1 HW version + software/firmware (I implement nanoVNA command set to be compatible with NanoVNA saver software). But I found some bug in HW (PLL internal interference), and did not have time to fix and finish (covid stopped all work and post service). But after some time I see on aliexpress V2, and now my project doesn't make sense.
Thanks again for nanoVNA V2, it is very very good. Also, for better calibration, you can change load with some better (I use amphenol 18GHz 50ohm load), and that improves s11 measurement

[JohnG]

We didn't go with a metal enclosure because it was found to worsen port to port isolation.

This can often be greatly helped by adhering a layer of carbon-impregnated anti-static foam to the inside of the case in strategic locations. The foam needs to be the black kind that DIP ICs and such used to come in. You should be able to measure some level of conductivity of the foam with an ohmmeter for it to work well.

John

[TimNJ]

Are you referring to ch_scr's case, post #2 of this thread?

Yes

Not sure if you mean you (HCXQS) will ship units with ch_scr's case, or it'll just become it the official 3D printing recommendation.

Two pieces of feedback, and one already noted:

1. Battery status indicators not visible (Add holes?)
2. The space for the 18650 cell should be a little bit longer, at least 72mm on the inner dimensions. No one should be using an unprotected 18650 cell, unless the NanoVNA V2 has built in battery protection IC. If not,  need 18650 with protection PCB. The allocated space in this design is only 67.5mm.

Typical protected cell here: https://www.jauch.com/downloadfile/5c3d9cd710f29e9c09d67ef33e58d94ac/3350mah_-_li18650jp_1s1p_2_wires_70mm.pdf

[OwO]

Yes, we got permission to let HCXQS offer the case on Tindie with the V2. The 18650 hole is lengthened, and the batteries have the protection board on the side, so lengthening it by 2mm was enough.
The enclosure material is translucent white and you can see the indicator LEDs.

[TimNJ]

Yes, we got permission to let HCXQS offer the case on Tindie with the V2. The 18650 hole is lengthened, and the batteries have the protection board on the side, so lengthening it by 2mm was enough.
The enclosure material is translucent white and you can see the indicator LEDs.

Cool. In terms of "sell-ability", I strongly believe the translucent material gives off a "less premium" look. I know we're talking about a $60USD VNA, so perhaps trying to say it's a premium product is a bit of a contradiction...although I do believe the hardware is excellent!

Something funny about the red and green PCBs together makes it seem like someone's Arduino project. I am typically very aesthetically minded, so those are just my comments. An SLA print is best, but SLS probably cheaper, but should be media tumbled after to get anywhere near a finished looking product.

As others have said, although it's an engineering tool (and perhaps looks shouldn't matter as much), most people buying these are every-day people acting as consumers. When they see a shiny V2 clone in a beautiful case next to a genuine V2 which ironically looks a bit half-baked, it's a tough decision.

[aargee]

I made my case out of red PLA and the LEDs show through the case nicely. 

[OwO]

As others have said, although it's an engineering tool (and perhaps looks shouldn't matter as much), most people buying these are every-day people acting as consumers. When they see a shiny V2 clone in a beautiful case next to a genuine V2 which ironically looks a bit half-baked, it's a tough decision.

Agreed, I'm going to forward your suggestion to do some post-processing on the 3D printed enclosure. Thanks!

[cdev]

I have quite a bit of experience trying to do this and it works with one caveat. The foam dries out in really hot environments and it may become problematic in the future. In order to work properly the popular wisdom is that it has to connect to metal on its backside but it can actually be put in a small thin plastic bag thats taped shut and then taped against the metal backing so that it wont deteriorate and cause shorting. This causes a significant improvement with LNAs input and output isolation. Also use ferrite beads on leads when its possible.

We didn't go with a metal enclosure because it was found to worsen port to port isolation.

This can often be greatly helped by adhering a layer of carbon-impregnated anti-static foam to the inside of the case in strategic locations. The foam needs to be the black kind that DIP ICs and such used to come in. You should be able to measure some level of conductivity of the foam with an ohmmeter for it to work well.

John

I also keep a bag of the larger picces of broken ferrites which I sometimes find useful. A couple of times its turned out to help with something, and is just what is needed.

Flat pieces are useful just as they are and C-shaped pieces - one half of a split bead, also may sometimes be very useful.

[JohnG]

Yes, one probably doesn't want conductive carbon-coated particles on their PCB. Works pretty well for a quick and dirty lab setup, though.

I do recall taking apart an satellite dish LNA not too long ago. It had similar foam pads all over the place, above transmission lines, couplers, mixers, etc. They seemed to be a little more robust, and maybe the foam felt like it was silicone based. No dust whatsoever inside the LNA. So, this sort of foam should be available without the problems of the carbon-coated foam, but I have never looked for it.

John

[rf-loop]

My NanoVNA V2 clone is in "metal box hybrid" with 3.2".
All sides sides, including ports are metal.  Switches are not between ports. Top and bottom of case is more or less plated PCB.

Directivity. I have seen truckload of HP, Agilent RF things including of course also differerent VNA's
Partially bit    but why they do not talk how metal case have some adverse effects...  they are metal and they are heavy and specially older ones all are deep inside aluminium casting.  They do not also tell that metal case destroy some values...  Of course they are expensive but what is real Root reason why peoples tell that metal case is bad. I like to hear Real reason. Where is this secret thing and why.  Is it perhaps so that there circuits are designed for "open air". Why they are dot designed so that metal case make it better instead of it give some negative effect.


I do not have seen any directly comparative images so I need ask how peoples who know more deeply this NanoVNA V2  think about this. Is this normal, more bad than normal or part of bit better group.  I am bit amazed overall how good this is related to price.
This question with image is also because I am really far from my homeland and I can not use my all tools so I really can not at this time make many kind of real tests with trusted data. 

Attached image.
First done SOL Cal (CH0)
After then run sweep from 1MHz to 3GHz and CH0 just same  50ohm load used in cal directly in port. (no cables)
NanoVNA firmware: 20200619
NanoVNA-Saver 0.3.6

[OwO]

S21 is a little out of spec above 2.8GHz, but that's just due to reflections by the metal enclosure.
S11 looks good.

[rf-loop]

S21 is a little out of spec above 2.8GHz, but that's just due to reflections by the metal enclosure.
S11 looks good.

Tnx.

Here perfectly same but now without metal "box" what is not just box. It is metal band round four sides. One side can open and bend bit and take out. Bottom and top are painted and clearly they are PCB and golden figures and name looks like they are just  PCB traces. But other way looks like PCB is without any conductive copper, only painted black. So true metal is only this band between these bottom and top cover.

Again SOL Cal and result is:

[OwO]

S21 is within spec now. Mind taking some pictures of the PCB top and bottom side? I'm curious what their layout looks like with the buttons and switches moved.

[rf-loop]

S21 is within spec now. Mind taking some pictures of the PCB top and bottom side? I'm curious what their layout looks like with the buttons and switches moved.

Yes 21 upper freq. noise level drops some amount without  case sides metal parts.

 I will later take it parts. I do not know how this battery is fixed (glued) inside this "sandwitch" but  when it was partially open it looks bit weird.  I want open it without damages and any signs I have opened it.  PM can not attach images. Also I do not have my camera here, only phone as "camera" but I will look some solution.

[cdev]

What happens when you terminate S21?

I often make temporary cases for my hardware out of cardboard because its easy to make and gets them out of harms way. In order to have shielding I then usually use either copper tape or sometimes I will use what you describe, a copper "O" a flat strip joined with solder with holes cut to give SMAs good ground points.

I will then often solder a wire to the copper tape to ground it to the chassis and also ground the power at the same point the DC power is attached.


USB noise is oten hard - very hard to get rid of.

[rf-loop]

What happens when you terminate S21?

USB noise is oten hard - very hard to get rid of.

Naturally no significant change. This is not designed just like toy. Even when price is what it is.

[bicycleguy]

Now here's a case.  It's a wonder what you can do with Covid-19 spare time.


Angled so you can see it.
Holds SOLT, attenuators and adapters in a drawer.
Holds a standard 18650 Li cell.
Lots of air holes for cooling.

[cdev]

Beautiful, I have some very nice recycled brown stiff cardboard I think is going to go into my case. What did you make the drawer out of?

[bicycleguy]

The whole works is 3D printed PLA fiber with faux wood, white and black text.  The top took about 3 hours and the base about 4.  The drawer took about  8 hours because I wanted to test modifications I had made to my multi-color Prusa printer.  The brown on the front caused the printer to switch colors every layer (182 layers).  If I had left it white it would have been about 3 hours even with the black text, because that text is only on 4 layers.