开云体育

Only good to 600MHz though.

--
Terry VK5TM
( )

NanoVNA need ~1-2ms for measure 1 point
Pause 0.5ms between measure points for wait si5351 freq lock (can be larger on band change)

Did a search on google using "bnc calibration kit" and had several hits that includes both male and female configurations along with a wide range of cost.

--
David S

One caveat to measuring at the end of a long cable is that the calibration and measurement may need to have the sweep speed reduced. A round trip reflection cal or measurement with a 100 M transmission line with a velocity factor of .66 will be roughly a microsecond.
This can be controlled on a commercial VNA - I'm not sure if the nanovna / saver has that capability.

Bob

Hello all-

received my nanoVNa from Amazon Sunday, have the Saver software running on
win10 ok.

Trying to also install on Ubuntu 18.04, but run into problems:

~/nanovna-saver$ python3.7 -m pip install .
Processing /home/dandell/nanovna-saver
Collecting PyQt5 (from NanoVNASaver==0.2.2)
Using cached

Complete output from command python setup.py egg_info:
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/usr/lib/python3.7/tokenize.py", line 447, in open
buffer = _builtin_open(filename, 'rb')
FileNotFoundError: [Errno 2] No such file or directory:
'/tmp/pip-build-dnr2o492/PyQt5/setup.py'
Error in sys.excepthook:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63,
in apport_excepthook
from apport.fileutils import likely_packaged, get_recent_crashes
File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in
<module>
from apport.report import Report
File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in
<module>
import apport.fileutils
File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23,
in <module>
from apport.packaging_impl import impl as packaging
File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line
24, in <module>
import apt
File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in
<module>
import apt_pkg
ModuleNotFoundError: No module named 'apt_pkg'

Original exception was:
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/usr/lib/python3.7/tokenize.py", line 447, in open
buffer = _builtin_open(filename, 'rb')
FileNotFoundError: [Errno 2] No such file or directory:
'/tmp/pip-build-dnr2o492/PyQt5/setup.py'

------------------------------
i have also checked to see if the other Python modules are installed and
they are

(You may need to install the additional packages python3-distutils,
python3-setuptools and python3-wheel for this command to work on some
distributions.)

any help out there?

Thanks Dan KC2STA

--
Dan Ziolkowski KC2STA
SKCC #4290T
Ubuntu LINUX

Don't know whereabouts you are.

I bought my nanoVNA-H from Mirfield Electronics here in the UK. Arrived in 4 days, well packed and included a couple of extras adapters for PL259/SO239 in the price. Satisfied customer.

I see that Passion Radio in France advertises the H model for 65 Euros.

A quick search should find both.

Chris

IN France, we have

In France we have,

Can you name them and/or give their website URLs?

I have been using Aramex Global Shopper (I'm normal client of the company) for the last 3 years - I provide an address in Hongkong for AliExpress and the shipment took 10 days to arrive there from Mainland China. Then it is another 10 days to my door in Pretoria, South Africa.

In this case I realised that I have a NanoVNA V3.1 Hardware (White Plastics) and decide I need a upgraded (V3.4). A bigger screen would be nice and with the support given by DisLord for this version, I decided on a -H4 from the Deepelec store on AliExpress.

Hope to have it in a few days. The shipping per courier adds $10-$20, but it is worth it given the Covid issues

Mike - That's been going on for 12+ months - I buy from China regularly and have been on several occasions. Generally there's no problems with the stuff leaving the factory but the distribution centres in Hong Kong are a different matter. See - some of my suppliers are now shipping via other centres. Covid just added to the inefficiency excuses.

In the other direction, there are countries that the USPS isn't even
accepting shipments to right now, either because their post offices have
shut down or because no transportation is available. Info here:

No need to speculate based on anecdotal cases:


There's massive disruption generally, some of us are lucky and some are
not.

73s,
Hajo

PGP key:

Her are some pictures.

Checked your picture, black and white are not made by us, but it seems that your black version uses the same circuit as ours, we only found a little difference on the PCB, as long as the test is normal, it should not affect the use .

hugen

All,

I'd like an inexpensive calibration set (open, short, 50 ohm load) for BNC (M&F) Any one seen such??

Larry, K4MLA

Calibrating to the end of a cable was SOP in the lab I ran and every
time some one would tell me it introduces error I'd give them what ever
time they needed to prove it. They all failed in their assertions
as did I when I had that assumption in my head many years before.

Your data is as good as the cal to the plane of the cal. Even with
45ft of RG400 at 400mhz it worked.

The only yabut of it is if the losses are so great and the cable
long enough it will eventually self terminate. At that point its
not useful to do a SOL cal at the far end as the reflections are
absorbed before they reach the instrument.

Allison
-----------------
No direct email, it goes to bit bucket due address harvesting in groups.IO

On Tue, 19 May 2020 at 22:36, pez@arg <petrosez7@...> wrote:

| On Tue, May 19, 2020 at 09:48 PM, <sj@...> wrote:
=
|
| I would say NO.
| Sorry to say, but have worked with VNA's for 30 years and as soon as you
come
| near 1/8 wavelength the measurement errors are taking over.
| You know, in the analyzer the matrices that are multiplied together, the
error
I matrice will start to influence significantly. It is very difficult to
say
| that it always will not work when exceeding 1/8 (because you are closing
in to
| 1/4 and the matrice in play will get 0's and infinite in some places)
because
| let's consider you are clever and you measure in a narrow sweep where
your
| cable length is not any close to a 1/4 wave multiplum, then it can
actually
| work to some extend.
|
| Generally if you can't evaluate when you are measuring correct, I
recommend
| you to keep your calibration point as close as possible to the analyzer
and
| respect you might have significant errors if your CAL point exceeding
1/8 wave
| length away from the port.
|
| People believing they can calibrate out 20 meter of coax at any
frequency,
| does not have any idea what they are talking about.

The standard Agilent cables for my HP 8720D VNA are 24" long, which is
about 600 mm. The maximum frequency of the VNA is 20 GHz, so a wavelength
of approximately 15 mm. Even ignoring the velocity factor of the cables,
that makes them 40 wavelengths long.

Maybe you mean something different to what I think you mean.

Dave

Thank you. I see it now. My old eyes need some magnification hi... hi

Tony VE3DWI.

On Tue, May 19, 2020 at 20:59 Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Tue, May 19, 2020 at 05:11 PM, Tony wrote:

Why are the two measurements not taken in the same display format? One
graph is in SWR one is in RL.

Tony VE3DWI.

They are all taken in the same format! All 4 graphs have both
measurements on them. The results are so close that one is directly
overlaid on the other and you can't tell one from the other except at a few
frequencies. Take a close look at this plot - I zoomed in to show the 2
plots.

Roger

On Tue, May 19, 2020 at 05:11 PM, Tony wrote:

Why are the two measurements not taken in the same display format? One
graph is in SWR one is in RL.

Tony VE3DWI.

They are all taken in the same format! All 4 graphs have both measurements on them. The results are so close that one is directly overlaid on the other and you can't tell one from the other except at a few frequencies. Take a close look at this plot - I zoomed in to show the 2 plots.

Roger