开云体育

On Thu, 26 Sep 2019 at 13:41, Rune Broberg <mihtjel@...> wrote:

Dr. Kirkby,
it does confuse me a little why you would buy a VNA from AliExpress, but
not a battery from Amazon. ;-)

I bought the NanoVNA from eBay - not that it makes much difference.

As long as ones expectations are correctly set - namely, to receive a
battery of an unknown capacity and quality, which might fail without
notice, but broadly speaking without catastrophic consequences, buying from
the sellers you mentioned should cause no particular problems.

Lithium ion batteries can fail with catastrophic consequences.

I know that the switch on the NanoVNA is of appalling quality, but I will
address that by an external switch.

The screen on the first NanoVNA I received was faulty - a problem Hugan
said is common.

A quick look found me this battery



a very reputable manufacturer, around 5 times the stated capacity of those
with the NanoVNA, at a cost of about 50% of the cheapest NanoVNA I have
seen.

I've seen no indications that the batteries sold on AliExpress or indeed on
Amazon should be any more dangerous than batteries bought elsewhere - and
given the price difference of roughly 10 times, the cheap batteries should
perform just fine for the average hobbyist reading this list and using a
NanoVNA.

I am certain that the capacity of the Chinese batteries on eBay are grossly
exaggerated - that’s based on tests I have performed. I don’t know about
reliability, having not done any tests, but I don’t trust cheap
batteries. Someone wrote in this thread his battery was bulging.

*Personally*, I would rather spend a bit more, get much higher capacity and
be more confident that the battery is of good quality.

*Personally* I don’t believe that the components of the NanoVNA are good
enough to use it without an external case. Therefore a physically larger
battery is not a concern to me.

Your recommendation to buy from a supplier for the *professional* market
does not particularly provide anything for the majority of us: Hobby users.

I don’t think the cost of a battery from a reputable manufacturer is that
bad for a hobby user, but ultimately these are personal choices. I did not
say any person must buy a battery from RS or Farnell, but just stated my
personal views.


--

Rune

Dave.

--

Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

On Thu, Sep 26, 2019 at 03:29 PM, Dr. David Kirkby from Kirkby Microwave Ltd wrote:

I would *never* buy batteries from eBay, AliExpress, Amazon or similar.

I bought NanoVNA on aliexpress in this store:

It comes with battery - 602040 3.7V 450mAh. The battery includes protection module.
I tested it, NanoVNA works 2 hours from a fully charged battery.

David,

yes, SWR (resonance) is fairly pertinent for an antenna. But once again, this does not
say, if this is a good antenna or not. Efficiency = good antenna is a matter of antenna
gain and resonance is only a small portion of it. A resonant short wave antenna in 1m
above ground will bring different results than one in resonance and 20m above. Both
of them will show a perfect SWR of 1:1 and other S-parameters, but the outcome ?

nanoVNA can only measure some technical parameters of your antenna - and they say
nothing about 'how good is this antenna' for receiving only ;-(

@erik@...:
/g/nanovna-users/message/3008

Hello,

First of all, allow us, please, to express, on the occasion,
our deep respect for your impressive Work with NanoVna.

Next, allow us, please, to inform you that just after the
message including the preliminaries of the uncertainty:

[6] : /g/nanovna-users/message/2968

we took into account your clear call for understanding
and thus we started a sequence of very short messages
on this subject, beginning with:

[10] : /g/nanovna-users/message/3043

Finally, allow us, please, to comment that, in our humble
opinion, regarding 'Understanding', there are the following
types of human beings, according their personal tastes:

(1) Those who don't want to understand, and those who want
to understand, but when they don't understand then, according
to their judging abilities, they put constantly the blame:
(2) on the others,
(3) on themselves, and
(4) either on the others or on themselves, according to the state
of their progress in the Knowledge

Keep up the Good Work !

Sincerely,

pez&yin@arg

13

Hi John,
thank you very much, and thank you for the kind description in your linked
post :-)

I assume you've calibrated on the NanoVNA? Or did you make an
in-application calibration? Either should be fine, of course.

Could I ask you to send me an exported S2P file of the data, please? I
would like to check how it looks.

I haven't previously seen a 10dB drop, and judging by the photo of the
filter on test, it doesn't show up on the NanoVNA itself. Can you verify
for me that it does not?

Thanks for reporting the problem!
--
Rune / 5Q5R

Not necessarily. A dummy load will have a good match - maybe even perfect - but does not make for a good antenna.

Attention: for those with an interest in employing a Linux system to

run Rune's application. All others skip over this post.

Don, at the risk of telling what you understand perfectly well,

permit an observation on the Linux systems of interest here. Even if you
understand already, others less familiar with Linux may be helped.

Window$ oriented users may be accustomed to "doing as they please"

in a Window$ system. I'm long, long out of Window$ and things may have
improved greatly over the years but, in the past, installing software
was unconstrained. That was one of the, er, open windows to malware.

In the Linux systems of interest here, the day to day user is just

that, a mere user and nothing more. Much in the "machinery" of the
system is closed to him and thereby to malware.

Installing software is something very important because that is a

route to malware entry. The root user, the ultimate systems authority,
is permitted to install software and to do anything else; the day to day
user is not. So, Don, never arrange the system so that, day to day, you
are operating as the root user.?? /None of us ever does that./ ? Please
don't think that by contriving your Linux system to operate like Window$
an improvement is being made. The reputation Window$ has established
over the years for security is all you need to know in that regard. You
don't want a system like that. Most of us ordinary Linux system users
don't use an anti malware program. Compare that, please, to Window$
systems where an entire industry has built up devoted to trying to keep
out malware and to clean up what does get in. At least in the past, a
good deal of c.p.u. overhead in a Window$ system was devoted to dealing
with malware threats. Not so in Linux.

The engineer mentioned, who is now using a Linux Mint system, is

employed by a company whose enterprise customers forbid the use so much
as a single line of Micro$oft code in anything his company ships right
down to cameras and video recording systems! When you see a news item
about institutions that have had systems failures or ransomware attacks,
listen carefully and look at the screens on the terminals. It's some
Micro$oft enterprise system that has failed. That's very dirty laundry,
too, and we will not be seeing even five percent of what is actually
going on.

So, then, how to install software such as that required to run

Rune's superb application? The way it is done is by "borrowing" the root
user's privileges. That is a very big step. The user "borrowing" root
user's privileges must consider very carefully what he is about in
installing software and what he is about in gaining access to sensitive
system directories and their files because, of course, he is exposing
his system to malware. The software to be installed must be known to be
clean of malware. There is very much to be said on the topic of assuring
that uncorrupted software or other files are being downloaded. There is
not room here to discuss the matter and, anyway, I am no expert.
Authoritative material must be consulted if you wish to follow up the topic.

What you almost certainly have encountered is an attempt to load a

file into an area of files owned by the root user. That was what Rune
meant by "permission". The machine will not permit a day to day user to
do that. A day to day user has no business in there and Linux is doing
its job of keeping itself clean. Having assured yourself of exactly what
you are about to do, you may assume, for the moment, the privileges of
the almighty root user without actually becoming the root user. The
command " ? sudo ? " says "System, permit me to assume the mantle of the
root user...temporarily." When you invoke that command, the system will
demand your root user's password. When you did the installation, one of
the things that the installing program asked you for was the password
that you would like to use as the root user. That password /must/ be
different from the normal, that is to say day to day user's, log in
password! You now understand why. If those two passwords are not
different, Don, change the root user's password at once and make the new
one a good one. A look on the web will show how that's done, it is simple.

When that demand for the root user's password is made following

entering a command preceded by " ? sudo ?? ", that robust root user's
password is entered.

With that root user's password entered in response to the challenge,

you are "The Man". You can get in anywhere and do anything. Be careful,
Don; as an inexperienced Linux user, you are playing with fire.?

When you come to execute certain sensitive routines other than

installing software, you may be required to use the " ?? sudo???? "
command. That is quite normal. It tells you to think carefully what you
are about to do. Something else it should say to you, when you have
built up some experience, is:"Is this making sense? Why is the system
suddenly asking for this root privilege? I have done this before simply
as an ordinary user. I'm going to stop right here and think what is
going on. Is something trying to get into my system?" Don't
automatically invoke root's privileges; know what is going on. Though
it's exceedingly rare, you may have come across malware trying to get
into your system.

Now after all that security talk, Don, malware might seem to be the

same issue it is in Window$; it certainly isn't but as a beginner it is
important to understand what being the root user is all about.

In conclusion...a free living Window$ user of many years' experience

may see all this as pointless pack drill. This is /not/ pointless pack
drill, Don. The fellows who have been working on the Linux based systems
over the years have not been laid back dilettantes. They are smart
cookies and, with the software wide open to invigilation, there are the
eyes of many other smart cookies picking over what they are doing. Any
change to the software has followed a strict protocol of testing and
inspection before it was ever released for use in a system. Please
compare that to the sorry record established by Micro$oft! Smart users
all over the world have contributed ideas for making the code even more
efficient and robust year upon year and the process is going on still as
you read this. Collectively these guys are smarter than any one of us.
We ordinary users do not know better. We are well advised to take
advantage of the Linux security protocols.

John

at radio station VE7AOV.

+++++


On 2019-09-26 2:45 a.m., Rune Broberg wrote:

Hi Don,
permission issues I can't really help with - I expect that's a matter of
being root or not, or using sudo or not.

On Windows, I'm sorry to hear that you're experiencing crashes. If you
would like to run the program with the parameter "-D logfile.txt" (or
another filename of your choice), you can create a log of debug statements
from the software, so I can see what's going on. Running the software from
a command prompt (cmd.exe) should also allow you to see the final error
message/stack trace - I'd like to have that as well for debugging!

Thanks for trying it out, and for taking the time to report the errors you
are experiencing! :-)

--

I'm in the UK but i can use antenna as well, same thing ;)

But the Nano can show the resonant frequencies of an antenna and that is fairly pertinent to how it would perform ?

David,
with NanoVNA you can not find out, if an antenna (think you called it 'aerial') is goo for your
purpose to receive signals, or not. Depends on your receiver, if it has an input impedance of
50 ohms, you could check, if your antenna has a good SWR or not. But SWR is only a matter
to match input (output) plus cable to the 'other side' = antenna. A good SWR says nothing
about the efficiency of an antenna. A 50 ohm resistor at the end of your coax cable will show
you an SWR of 1:1. This will be a perfect reading of S11, but that's not a good antenna.

To bring it to the point: nanoVNA is not a tool to let you know, if you are having a good and
efficient antenna for your existing receiver and the frequency you want to listen at all..

Hi all,
I have a NanoVNA, great little gadget, I'm interested in in aerials, at present for receiving only.

What would be the best output to look at for this purpose, i think its going to be S11 LogMag or SWR ??

Also if i was looking at say S11 Logmag results, what would be a value that tells me "this aerial is no good at that frequency" ??

Something like -10db or what??

Many thanks

Dave

Rune, many thanks for developing this software and making it available to us all. It *greatly* increases the enjoyment of using and learning the nanoVNA.

I went through the full 2-port cal yesterday and then used the device/program to graph the response of a band reject filter. I'm wondering why, after the cal routine, the S21 line is at a -10 dB level? I don't see a way to zero it prior to making a measurement, so all the data relating to any measurement will have a 10dB error...or perhaps I'm missing a step?



Thanks again and 73,

John AE5X

Dr. Kirkby,
it does confuse me a little why you would buy a VNA from AliExpress, but
not a battery from Amazon. ;-)

As long as ones expectations are correctly set - namely, to receive a
battery of an unknown capacity and quality, which might fail without
notice, but broadly speaking without catastrophic consequences, buying from
the sellers you mentioned should cause no particular problems.

I've seen no indications that the batteries sold on AliExpress or indeed on
Amazon should be any more dangerous than batteries bought elsewhere - and
given the price difference of roughly 10 times, the cheap batteries should
perform just fine for the average hobbyist reading this list and using a
NanoVNA.

Your recommendation to buy from a supplier for the *professional* market
does not particularly provide anything for the majority of us: Hobby users.

--
Rune / 5Q5R

On Thu, 26 Sep 2019 at 14:29, Dr. David Kirkby from Kirkby Microwave Ltd <
drkirkby@...> wrote:

On Thu, 26 Sep 2019 at 12:57, Carlos Cabezas <eb4fbz@...> wrote:

My battery started swelling after two charges. I am afraid it could
explode or damage the nanoVNA due to the pressure. I will change it as

soon

as possible.

Bought at AliExpress Guangyi0016 Store.

I would *never* buy batteries from eBay, AliExpress, Amazon or similar.
Just buy from a reputable distributor of components for the *professional*
market. In the UK, I would use Farnell, RS. Digikey would be sensible in
the USA. Use something made by Panasonic or other manufacturer of
batteries. If you buy from eBay or similar, you are likely to get 100%
genuine fakes.

As for claimed capacity, these seem to be generated with random number
generators.

If one mounts the NanoVNA in a larger enclosure, to make it more
mechanically reliable, then within reason, one can probably choose what
capacity battery one wants, although it would be sensible to check the data
sheet on the charger chip - someone did give the part number on here a few
weeks ago.

Dave.
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

On Thu, 26 Sep 2019 at 12:57, Carlos Cabezas <eb4fbz@...> wrote:

My battery started swelling after two charges. I am afraid it could
explode or damage the nanoVNA due to the pressure. I will change it as soon
as possible.

Bought at AliExpress Guangyi0016 Store.

I would *never* buy batteries from eBay, AliExpress, Amazon or similar.
Just buy from a reputable distributor of components for the *professional*
market. In the UK, I would use Farnell, RS. Digikey would be sensible in
the USA. Use something made by Panasonic or other manufacturer of
batteries. If you buy from eBay or similar, you are likely to get 100%
genuine fakes.

As for claimed capacity, these seem to be generated with random number
generators.

If one mounts the NanoVNA in a larger enclosure, to make it more
mechanically reliable, then within reason, one can probably choose what
capacity battery one wants, although it would be sensible to check the data
sheet on the charger chip - someone did give the part number on here a few
weeks ago.

Dave.
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

My battery started swelling after two charges. I am afraid it could explode or damage the nanoVNA due to the pressure. I will change it as soon as possible.

Bought at AliExpress Guangyi0016 Store.

On Thu, Sep 26, 2019 at 07:32 AM, BruceN wrote:

Where can we find the rest of this manual. Appears easy to read.

Bruce, K4TQL

Where can we find the rest of this manual. Appears easy to read.

Bruce, K4TQL

I had suggested this in a post from 2 weeks ago - to grey-out/disable the other on-screen buttons when the transform function is used.
I think I'll have to enter it as an issue on git.

@Gary O'Neil :
/g/nanovna-users/message/3070

Hello,

And thank you, once more, for your most
valuable contributions !

Well,

(1) regarding the objective requirement
for a distribution of the REGION executable,
allow us, please, to notice the useless result
of such an action, because, once again, this
file is not a standalone program but it constitutes
just the one part of this two-part /F/L/O/S/S/, and

(2) regarding the subjective concerns you most
reasonably expressed about your time, also
allow us, please, to notice that since the personal
taste is the decisive criterion that governs humans'
choices, and since the expediencies of any kind
were never dictated our acts, we are not be able
to the slightest to suggest you what to do in order
to meditate these worries of you.

Finally, since we mostly respect your efforts and
your time you spent to take a look at our humble
work, allow us, please, to conclude our communication
by thanking you, once again, very much!

Sincerely,

yin&pez@arg

Thank you Pluto

Hi Don,
permission issues I can't really help with - I expect that's a matter of
being root or not, or using sudo or not.

On Windows, I'm sorry to hear that you're experiencing crashes. If you
would like to run the program with the parameter "-D logfile.txt" (or
another filename of your choice), you can create a log of debug statements
from the software, so I can see what's going on. Running the software from
a command prompt (cmd.exe) should also allow you to see the final error
message/stack trace - I'd like to have that as well for debugging!

Thanks for trying it out, and for taking the time to report the errors you
are experiencing! :-)

--
Rune / 5Q5R

On Thu, 26 Sep 2019 at 11:19, Don Vosper via Groups.Io <donald.vosper=
[email protected]> wrote:

Hello.
I am new to Vector Network Analysers and I thought I would take advantages
of this affordable piece of test gear to learn something.
I am finding my way round the menus ok with the stand alone item but have
hit a couple of stumbling blocks with the Nanovna-saver software.
Running nanovna-saver.exe with windows 10 I can connect to the VNA ok but
the program crashes when I start to enter parameters. On occasions if I
enter parameters and connect in a certain order I get results but after a
while when changing things it will crash.
I though I would try it on Linux Mint. The installation went well until I
tried to instal pyqt5. I was unable to do this as it says I don't have
permission to download to the particular folder.
Any advice would be gratefully received.
Don, m5aky