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OK well I know that the supplied battery is about 350-400ma and I get about 2.5 hour running time.
That to me says that the battery it good.

So it could be a high leakage / quiescent in the switch controller, or that I'm getting a bit old and forgetting just how
much I may have used my Nano VNA without charging it.

Both a highly possible ;-)

As for shelf life normally.

I have a whole bunch of Li-Ions in use here, 18650's, HT battery packs, spare cell phone packs.

I'd say that I would expect to find a 90% charge from anything from 3-6 months, or even 12 months.

Bit some cells seem to be worse than others, so it's not guaranteed.

The worst case is a spare cell phone battery that holds loses 50% in about 6 months.
These figures assume that I have properly isolated the terminals from the equipment.

Otherwise it is easy to be mislead.

My Wouxun HT's are quite poor in this respect, they would need a good top up charge after a few few weeks if not isolated
due to power switch leakage.

On the other hand, my Baofeng UV5R and others don't seem to give rats ass about storage and easily hold 80% charge for
6 months or more. Not Nano VNA related, but a useful comparison of shelf life.

Sent just for info only...

73 de Andy

Same problem here. I purchased two from eBay seller harborcityelectronics, see item # 121096249091. Repair was straightforward with no issues and I have a spare.

73

-Jim
NU0C



On Mon, 06 Jan 2020 06:39:04 -0800
"slawomir.kleczyk" <ssb@...> wrote:

Hi to all,
a few days I received NanoNVA-F. I bought on Aliexpress. Unfortunately, the rotary switch only worked one way and blocked the functions on the touch screen. I had to undress it but repair is impossible. Does anyone know what type of this switch is and where to buy it? The seller has not yet responded to my complaint.
Happy New Year
Slawomir

On Mon, Jan 6, 2020 at 03:06 PM, Aleksander Shalygin wrote:

For an N connector, the seller must have an adapter option with a calibration
kit.
My counterpart. It is very convenient to work. And the BNC option should be
similar.
It solves many technological problems in production. (Apologies for bad
English from Uncle Gogl.)

It is really a good design. I am trying to improve the performance of the current version of nanoVNA 300-900MHz. I will consider using N-type connectors after completing the related improvements. Will also consider letting edy555 make similar attempts in his next-generation VNA.

hugen

At the beginning I added ip5303 to NanoVNA just for my convenience. But I didn't expect it to be so popular with the community. Now I have realized that this design is not reasonable and has been improved in NanoVNA-H rev3.4.

hugen

On Mon, Jan 6, 2020 at 07:09 PM, hwalker wrote:

On Sun, Jan 5, 2020 at 08:57 PM, <hugen@...> wrote:
English translation with the help of "Microsoft Translate" …..

Hope not too much was lost in translation.

- Herb

Thank you for your translation.

hugen

I finally found a few posts relating to this in the archives, and have to agree there's a problem. Someone had measured about 60?A of leakage when off - try measuring this on your unit and see how far it's off. At 60?A, this should last several months without charging - if it's flat in a month, that battery's not holding a charge as it's supposed to. (The Injoinic datasheet for their IP5303 says typical of 100?A quiescent current draw when off.)

IMHO, the charging system with the IP5303 is very wrong for the typical battery capacity of 0.4 to 0.45 Ah. Thus I'm worried about my battery now as I charge it. The battery, if you have a good cable and the power supply can do it, will be taking in a charge greater than 1C. This stresses the battery and likely will cause premature battery failure in cheap batteries.

The IP5303 is so inflexible that the only thing I can think of doing that doesn't waste charge energy is adding another battery in parallel, which will give enough load to balance out its seemingly inability to reduce charge rate for smaller cells. The IP5303 probably is expecting at least 1.5Ah of capacity or so, and likely less than 3Ah.

The power wasteful but simple solution is adding a resistor into the USB charging path to limit charge current. Maybe 0.33 ohms or so. This should improve the life of the battery pack, both cycle count and hopefully prevent pack failure, at the cost of charging time (and a resistor).

On Mon, Jan 6, 2020 at 01:37 PM, Andy wrote:

" .. I had mine charged, and left it on the shelf for a few weeks and it died on me."
===========================================================
All battery powered devices exhibit some self discharge during storage. My cellphones and tablets when completely powered down require recharging after a few days. A few weeks in my opinion is a pretty good shelf life for a 400 mAh device. Both of my NanoVNA's were delivered via slow boat from China, and were in transit for over 3 weeks. Both retained enough charge to power on when they arrived.

Depending on supplier, some batteries may be better quality than others so its hard to make a blanket statement regarding battery performance from a product like the NanoVNA that has multiple suppliers. I noticed hugen's new version 3.4 pcb has a 650 mAh battery instead of a 400 mAh one. This should translate into longer operating time, at least until the 4" display is added.

- Herb

I've noticed that my second unit's battery is starting to swell a bit. Time to swap it out.?

I think the batteries used on the copies of hugens unit are of low quality and are not lasting? as long as they should.? It might also be the counterfeit ip5303 charge controllers on some units as well...the ones that fail to sense load after a while and you need to add the power-on button to pin 5.?

YMMV



On Mon, 6 Jan 2020 at 4:38 PM, Andy via Groups.Io<punkbiscuit@...> wrote: Has anyone noticed that the shelf life of the Nano VNA seems a bit short ?
I had mine charged, and left it on the shelf for a few weeks and it died on me.
Seems to me to be some sort of high quiescent stand-by state possibly through the switch controller ?

Operating life, when charged and immediately used is good though, indicating the battery capacity as being about 400ma.

73 de Andy

Has anyone noticed that the shelf life of the Nano VNA seems a bit short ?
I had mine charged, and left it on the shelf for a few weeks and it died on me.
Seems to me to be some sort of high quiescent stand-by state possibly through the switch controller ?

Operating life, when charged and immediately used is good though, indicating the battery capacity as being about 400ma.

73 de Andy

Google translate had a slightly different but important statement at the end on availability....

"AA6KL is further improving its development. NanoVNA-H with STM32F303CCT6 and 4-inch display will be launched soon. I hope that the community can have more fans"

Looking forward to seeing them on the market before too long...

Roger

This is the weakest element of this device. It has not worked since the beginning. I have 3 weeks. I need information about the type of this switch and where to buy it. I will order 2 pieces.

had the same issue with mine,the flimsy legs snapped off my jogwheel,managed to dremell away the plastic put 3 blobs of solder on the remains of the legs then sweated it back on the pcb,good idea but a crap quality switch!

That is the screen i fitted to mine,works a treat,quite cheap as well.

i found the jog wheel fine to use,just a badly made piece of crap tho!,would be fine if better made!

The errors scale proporionally with wavelength. I use my VNA mainly around 900 MHz in RFID development and applications. Here a single mm path length is on the threshold of an acceptable error for me. So scaling up in wavelength 30 times, we arrive at 30 MHz and 30 mm will be the length of wires that may start to be a source of errors.
Wavelength at 30 MHz is 10 meters, 30mm is just 0.3% of 10 meters. So you're fine if you keep the wires a bit short, or lower the frequency to 3 MHz. Then, it hardly matters anymore. But you can easily measure yourself the return loss of a 50 Ohm resistor connected with alligator clips, and measure short and open. This is the easiest if you calibrate the VNA at the end of the (SMA) cable. Solder the alligator clips with short wires to a female SMA connector.

Op 6-1-2020 om 17:29 schreef entilleser via Groups.Io:

I'm sometimes (often) also mathematically challenged so I perform a sanity check when doing these type of measurements.
Instead of the coil connect a 25 ohm 1% resistor (or some other value different from 50 ohm but not too much) and see if this is indeed being measured as pure 25ohm. There should be no capacitance or no induction. Any deviation will probably also happen when measuring your coil.
This will tell you at least if your calibration using your homemade fixture makes sense.
--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK

To the mathematically inclined from the mathematically challenged...

I understand the obsession with eliminating measurement errors. But how much error are we really talking about here? Suppose I take a short piece (say 6 inches) of 50 ohm coax cable, crimp a male sma connector on one end, and a couple of alligator clips on the other end. I "calibrate" with the alligator clips dangling (open), then with a short piece of wire (short), and, finally, with a non-wirewound, 50 ohm 1% resistor (load). Then I go to measure inductance of the coil I hand wound for my crystal radio. Are we talking 1% here? 10%? 100%? 1000%?

I understand that the error in such as setup is going to increase with frequency. But, say, between 3 MHz and 30 MHz...? Below that? Above that?

I also understand that there will be many factors affecting this setup: resistance between the alligator clips and whatever you have clipped into them; random capacitance and inductance from nearby stuff; temperature, humidity, spilling your coffee on it... If the effect of all possible factors affecting measurement using such a setup are just too great to make any kind of ball-park assessment of the range of error, you could just say that.

Thanks, ahead of time, for insight into this question.

Slawomir,
BH5HNU, the developer of the NanoVNA-F, is generally responsive to hardware issues when you bring them to his attention at /g/nanovna-f/messages . You might leave a message for him at the above link and see if he offers any remedies before attempting any repairs.

- Herb

On Sun, Jan 5, 2020 at 04:42 PM, Birdman wrote:

When you purchase on amazon, YOU decide which sellers you purchase from, OR
you let Amazon decide. That could be what you are doing wrong, and why you
report amazon sending you their choice of product. If you click on the
sellers list, you can choose which one you wish to use.

I was referring to instances when the sellers item says "fulfilled by Amazon" and that happens a lot, then you no longer have a choice, they will make it for you, and sometimes there are no other options. I am not new to Amazon either so I am not doing anything wrong, all I am saying is that for me ebay works much better and is much easier to deal with, at least for the US. Not sure about the UK or elsewhere. For a while I compared items of interest on both sites, and sometimes still do, but 90% on Amazon it would usually cost a bit more, or have added shipping costs, so I use them only if there is absolutely no other alternative. The $25 free shipping is also another nuisance when trying to buy small stuff, you always end up having to spend more buying just yet another one or sometimes even two additional small "filler" items that Amazon conveniently provides to make it past the minimum. Classic trick. No such thing on ebay, plus you can safely pay through Paypal with one click. Oh and you get ebay bucks (1% cash back) on almost any purchase...

Good for you if Amazon works well for you. But are you sure you might not be doing something wrong on ebay?
Anyway, thank you for your input and that's it for me on this discussion.

Not claiming I am competent to do this I would like to try to summarize in limited amount of words what this thread has provided

It adds value for VNA measurement, due to its internal transform, to understand the impact of the magnitude of measurement errors (such as noise) or not well characterized calibration standards on the calculated values, in particular to understand the impact pending the position on the Smith chart. (referring to the DERR part of the communication)
It is possible to formulate an elegant, rather compact formula to calculate G solely based on g,s,o,l,S,O and L
It is possible and it makes sense to compare 1 port (S11) measurement performance of two VNA's measuring the same load if these have been calibrated using the same calibration standards and approach (this is regardless if this has been done using SOL or any other calibration approach, the use includes the utilization of the description of the used calibration standards, either as perfect, parameter modeled or data based) as the results of these measurements should be equal.
--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK