开云体育

I have a suspicion that they are not the right material for the low frequencies involved (3.5-14 MHz).

For these frequencies, the key is the number of turns. You need a ring (not a snap-on cylinder), and thread the coax as many times as you can through it. If your application is QRP or RX only, use thin coax (like RG-174).
A single snap-on only helps on VHF. You need a dozen of them to see a difference.

73, Mike AF7KR

Hope they will not use integrated ADC, because it will reduce performance a lot.

Additional tidbits of information.

1. The V2 PCB is 4 layers.
2. The schematics will be posted soon, at the same time as the launch on taobao,
3. Design objectives include keeping BOM cost below $100 and compatibility with current software base.

A contact located in China indicated that the schematics are available now but only via private request. I haven't seen any info regarding screen size, but Hugen has posted in the past about prototyping with a 3.5-inch LCD. I would expect something that size or larger to keep up with the nanoVNA-F that is now being sold.

Hi Rune,

I asked because some programs require minimal resolutions, otherwise dialog boxes etc. are cut off. Good to know that this is not the case with nanovna-saver.

Regards,
Arndt

Am 24.09.19 um 16:22 schrieb Rune Broberg:

It almost looks like you already have! ;-)

I'll definitely consider it.

--
Rune / 5Q5R

It doesn't *require* any particular resolution, but the interface only fits
in the vertical direction if there's at least ~750 pixels. So there would
be scroll bars. It's not the end of the world. :-)

--
Rune / 5Q5R

On Tue, 24 Sep 2019 at 16:00, diesolinger via Groups.Io <diesolinger=
[email protected]> wrote:

Hello,

What is the minimal screen resolution for nanovna-saver? I have an old
netbook with 1024 x 600 pixels which I could take with me to connect to the
nanovna.

Regards,
Arndt

Hi RUne,
Might you be able to add a port rescan button so we don't have to restart the application if we change USB ports?

Thanks,
Larry

Hello,

What is the minimal screen resolution for nanovna-saver? I have an old netbook with 1024 x 600 pixels which I could take with me to connect to the nanovna.

Regards,
Arndt

Hi Erik
Super, I will test it within a couple of days as I am on a job where T-Check will be made
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af erik@...
Sendt: 24. september 2019 11:52
Til: [email protected]
Emne: Re: [nanovna-users] on the comparisons

Kurt,

Allow me to share my T-check excel spreadsheet.

Copy your 2 port touchstone data into the yellow cells and the graph will show the deviations

Hope I did not make a mistake in the calculations.

Reginald, if you can spare a moment or two, please contact me off list.

Thanks.

John

at radio station VE7AOV.

if455kc@...

+++++


On 2019-09-23 7:38 p.m., Reginald Beardsley via Groups.Io wrote:

I think this promises to be a very interesting thread.

I spent my career solving wave equation problems.

...

--

Just tested previous firmware it works stable with 1 kHz span. Yes, it has wrong measurement with span below 100 Hz. But the new firmware is unstable below 10 kHz, this is much more worse...

Hi to everyone,

About the nanovna2. I really dont mind the screen size. I have the first
one and find it ok. The only thing is that if used outside it is low in
lights. But the size, not a problem, I have glasses and that what they were
ordered for, helping me see smaller thing clear.

the size of the beast is what I am looking for as I can take this little
gem and brint it with me in my shirt pocket on the top of the tower. And if
I need a bigger screen I can run nanovna Saver to display the result on my
laptop screen. Heck I could even make a small 3d printed box with a
nanovan, a raspberry pi4 and a touch lcd screen and run all this out of a
few lipo battery to have a nice large display. But it would not floor me in
top of the tower up to that point.

Making it run up to a few ghz on the same screen for about the same price
would be for me the best selling point of a nanovna2

Size does matter, but not always for the same reason.


Le mar. 24 sept. 2019 à 07:45, Dr. David Kirkby from Kirkby Microwave Ltd <
drkirkby@...> a écrit :

On Tue, 24 Sep 2019 at 11:01, <erik@...> wrote:

If you want a really big screen you can easily build on yourself using
very similar HW and some ebay modules.

Two ADF4351 generators, a resistive bridge and some AIM81001 mixers dead
bug style on a PCB is all you need.

I don't have the time to build a VNA. I wish I did, but given I have 4

VNAs here going up to 20 GHz, building another is not high on my priority
list. Perhaps if I was retired, it is something I would do.

When I briefly showed the NanoVNA at my radio club, several remarked they
could not see the screen as it was too small. I would add, the average aget
of the members in my radio club must be late 60's, with the oldest being in
their 80's, and the youngest in their 50's, so their eyesight is probably
not as good as a youngster. Unfortunately, at least in the UK, there are
not that many young hams.

But I'm happy with 10% accuracy where others on this group may need 0.01%

accuracy

I would be happy with somewhere between the two for a portable unit ? I
mentioned some places (NPL, METAS) and papers on measurement uncertainty in
another post since someone asked about it.

--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100

Hello,

Allow us, please, to summarize briefly:

(0) The measurement uncertainty is error-bounds of the
measurement.

(1) If a measurement does not involve mathematical expressions
then someone can choose the statistical way he likes to
mathematically estimate|compute a subjective uncertainty .

(2) If a measurement involves known mathematical expressions
then either there is or there is not -up to now- a known, unique,
mathematical way, that is a way solely based on these
mathematical expressions alone, to estimate|compute an
objective uncertainty.

(3) A vna measurement involves known mathematical expressions
and after more than ten 10 years there are now five 5 known
mathematical ways to estimate|compute a unique objective
uncertainty, each one for each of the five 5 "error" models considered
(by intermediately estimate|compute the errors of these "errors"),
as well as new one(s), the sixth 6th (or more), shall be added
as soon as the "error" model(s) of the NanoVNA will be revealed.

(4) These "errors" of "error" models are just historical names of
parameters mathematically expressed in terms to what is widely
known today collectively as "S-parameters" and thus these are
not error bounds - they are not uncertainties of the measurement.

Sincerely,

yin&pez@arg

6

n Tue, 24 Sep 2019 at 10:28, <reuterr@...> wrote:

Hello Erik,
Thank you for adding your extension to the Hugen nanoVNA version 0.1.1.

It would be nice to fill out in the "version window" the version number,
e.g.: 0.1.1 + scan, 1500MHz

It can be done in file ui.c line 385
#define VERSION "0.1.1 + scan, 1500MHz"
void
show_version(void)

In the version of firmware in mine, which I don't know what it is, a

screen similar to that does display. But it is for such a short period, I
can't read it. I guess if I used a phone to video it, I could probably work
it out, but it is too quick for my eyes and brain to process.

Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100

On Tue, 24 Sep 2019 at 11:01, <erik@...> wrote:

If you want a really big screen you can easily build on yourself using
very similar HW and some ebay modules.

Two ADF4351 generators, a resistive bridge and some AIM81001 mixers dead
bug style on a PCB is all you need.




I don't have the time to build a VNA. I wish I did, but given I have 4

VNAs here going up to 20 GHz, building another is not high on my priority
list. Perhaps if I was retired, it is something I would do.

When I briefly showed the NanoVNA at my radio club, several remarked they
could not see the screen as it was too small. I would add, the average aget
of the members in my radio club must be late 60's, with the oldest being in
their 80's, and the youngest in their 50's, so their eyesight is probably
not as good as a youngster. Unfortunately, at least in the UK, there are
not that many young hams.

But I'm happy with 10% accuracy where others on this group may need 0.01%

accuracy

I would be happy with somewhere between the two for a portable unit ? I
mentioned some places (NPL, METAS) and papers on measurement uncertainty in
another post since someone asked about it.

--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100

On Tue, 24 Sep 2019 at 09:43, Wolfgang Kiefer <woki@...> wrote:

Hello, Mr. Kirkby,
would it be possible to reduce your unnecessary lines to the essentials?
It would increase the readability of your inflated messages...

The name of my company, it's company number, where it is registered, and
the registered address is required under UK law.

I would have thought my messages are shorted than most, as I only quote
relevant content, and remove all irrelevant stuff.

--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892

Tel 01621-680100 / +44 1621-680100

It seems not

I saw his schematics and RF simulation files too when it was public repository.
/g/nanovna-users/message/2148

Seems NanoVNA2 dev hiding his works...

On Mon, 23 Sep 2019 at 16:55, <erik@...> wrote:

The nanovna has a very strong 1KHz component - probably a result of the
1KHz codec frame-rate.

I opened the nanoVNA and connected the line in of a good USB audio device
to the reference SA612. But as I did not dare to do two connections the
unbalanced signal had a lot of noise. And there were 1kHz peaks independent
from the selected output frequency, possibly coming from the PC itself as
connecting the audio input to the ground of the nanoVNA gave the same noise.
Looking with a scope showed a very clean triangular 5kHz signal, although
with some jitter that might explain some of the disturbances we see.
As disconnecting the USB resets the nanoVNA U was not able to measure with
disconnected USB as I do not know how to stop the sweep (e.g.the writing to
the SI5351) from the UI

As another way to isolate the source of the 1KHz peaks I ran a test where I
adjusted the PLL in the tlv320 so it would generate a different sampling
rate. It was a one line change to tlv320aic3204.c, line 46:
I2CWrite(AIC3204_ADDR, 0x06, 0x08); /* J=8, was 10 */.

With the correct value, the frame-rate calculation is: 8.000MHz*10.7520 =
86.016MHz, 86.016MHz/(2*7*128) = 48kHz /48 = 1KHz frame rate
With the modified value, the frame-rate calculation is: 8.000MHz*8.7520 =
70.016MHz, 70.016MHz/(2*7*128) = 39.07kHz/ 48 = 814 Hz frame rate

With the correct value, the FFT at 1.23GHz is:

[image: image.png]
With the modified value, the FFT at 1.23GHz is:

[image: image.png]

The peaks are now approx. 800Hz, which closely tallies with the modified
frame-rate.

I think this is pretty good evidence that these peaks are related to the
frame-rate, not usb or Si5351. The strongest suspect is coupling from the
CPU, which does its heavy dsp processing once each frame

Rgds,
Dave

I use a home build VNA for measurements above 900MHz so have no interest to buy anything else.