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I saw this



Thought might be of interest to some.

72

Dom
M1KTA

Nice idea. I wonder how long those little u.fl connectors will last though.

Probably not long.
I am sure there are much more robust connection options available but <$30 for a set of possible uses doesn't exactly seem that expensive (you could make your own of course) but I guess if want to check functionality might be an idea.
You got a nice smith chart blank on one side to photocopy and own use etc :-)

72
Dom
M1KTA

I believe thay are rated for fewer than 10 insertions.

On Thu, 3 Oct 2019 at 09:53, Gerry Kavanagh via Groups.Io <gerrykav=
[email protected]> wrote:

Nice idea. I wonder how long those little u.fl connectors will last though.

Hirose, the designer of the U.FL connector, says *20 matings. *

IMHO, it would be cheaper and better to just get some chassis mount SMA
connectors and assemble something oneself. eBay item 183574973423 has 5 SMA
connectors at $2.80 delivered to the UK.

* Opens can be made free.
* Shorts can be made for the cost of a bit of solder.???
* Other devices can be made very cheaply.

Working out the S-parameters

If you look at the cost of that board, it is *much* more expensive than far
more sophisticated PCBs available from China. To me at least, it seems a
relatively large amount of money for something that has very little
substance to it.

SDR-KITS sell a test board that seems to offer much more room for
experimentation at a better price.

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, Oct 3, 2019 at 02:44 PM, Dr. David Kirkby from Kirkby Microwave Ltd wrote:

SDR-KITS

You mean this one?


The suggestion of the ebay board stimulated discussion which is a good thing as I suspect some will have a need to see could this test 'whatever' and if it does what does the output look like?
I would have thought either might be a step up from a veroboard or a bit of FR4 (or better) with an SMA on either end and some test circuit or mount in between.

I am sure many of us have created such PCB with bnc/sma etc at either end you put/mount/wire some test rig or item in between.
Might be a guess but expect lpf/bpf, xta filters, RC/LC networks and a number of devices have been tested in this manner before (not with the nanovna of course)

If you have alternative suggestions for ready made cheap test boards I am sure many would love to hear about them?

72

Dom
M1KTA

On Thu, 3 Oct 2019 at 15:15, Dom Baines M1KTA via Groups.Io <dombaines=
[email protected]> wrote:

On Thu, Oct 3, 2019 at 02:44 PM, Dr. David Kirkby from Kirkby Microwave
Ltd wrote:

SDR-KITS

You mean this one?


The suggestion of the ebay board stimulated discussion which is a good
thing as I suspect some will have a need to see could this test 'whatever'
and if it does what does the output look like?
I would have thought either might be a step up from a veroboard or a bit
of FR4 (or better) with an SMA on either end and some test circuit or mount
in between.

I am sure many of us have created such PCB with bnc/sma etc at either end
you put/mount/wire some test rig or item in between.
Might be a guess but expect lpf/bpf, xta filters, RC/LC networks and a
number of devices have been tested in this manner before (not with the
nanovna of course)

If you have alternative suggestions for ready made cheap test boards I am
sure many would love to hear about them?

72

Dom
M1KTA

Yes. Note that there’s a basic board and are more advanced one. Both are
under ?20. I think that they are designed to be *educational*.

I am not saying that the Chinese board is totally useless, but for a PCB
with connectors that have quite a limited lifetime, and a small number of
cheap components, it seems quite expensive to me.

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

If you have alternative suggestions for ready made cheap test boards I am sure
many would love to hear about them?

FWIW, I got this $6 SMA attenuation breadboard


Dremel open the 0dB line and attach UHF DUT of interest.

On Thu, 3 Oct 2019 at 16:13, Oristo <ormpoa@...> wrote:

If you have alternative suggestions for ready made cheap test boards I

am sure

many would love to hear about them?

FWIW, I got this $6 SMA attenuation breadboard


Dremel open the 0dB line and attach UHF DUT of interest.

To now there are two options
* $28 for a board that will wear out after about 20 connections. (Date from
Hirose datasheet)
* $6 for one which will last 500 matings (Generally accepted lifetime of
SMAs)

The other option you have with the $6 board is to remove the shunt
resistors and put the DUT in series. Depending on the impedance of the
device, different methods are more appropriate.

To me, that $28 board seems overpriced for what it is.

--
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

You got a nice smith chart blank on one side to photocopy and own use etc :-)

Here is a Smith Chart that need only be printed:


It is generated using gnuplot, my favorite data plotting package:

On Thu, 3 Oct 2019 at 22:14, Oristo <ormpoa@...> wrote:

You got a nice smith chart blank on one side to photocopy and own use

etc :-)

Here is a Smith Chart that need only be printed:


It is generated using gnuplot, my favorite data plotting package:


Do you have any gnuplot code which can import a Touchstone file and plot

it on the Smith Chart? I produce all my plots for VNA cal kits usin
gnuplot, as one can automate everything, reducing the risk of errors. But I
have never plotted it on a Smith Chart - only amplitude and phase on the
same graph, using two y-axes,

My company logo has a Smith Chart in it - I generated that with gnuplot.

Dave
--
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

Do you have any gnuplot code which can import a Touchstone file and plot it on the Smith Chart?

Nope, I always reformat data before gnuplot so that it reads in
traditional columns.

Attached should be the gnuplot Smith Chart command files

On Thu, Oct 3, 2019 at 05:33 PM, Dr. David Kirkby from Kirkby Microwave Ltd wrote:

To now there are two options
* $28 for a board that will wear out after about 20 connections. (Date from
Hirose datasheet)
* $6 for one which will last 500 matings (Generally accepted lifetime of
SMAs)

Or three... Fit a RCA/0.1" pins/BNC/SO239/SMA (depends what freq range and what is to hand) to either side of a pcb and the DUT (Device Under Test) in between.
Even less than $6 probably assuming you have the PCB etc.
Before comments made about not using SMA yes I 100% understand you are not going to get ?100K kit/lab grade results with a couple old RCA either side of a random bit of PCB, indications probably at best, but then this is a ?50 device in the first place so got to set expectations perhaps? Think I made up and tested 1st HF BPF when and M3 using two RCA (with an expensive VNA) so I know it works, sort of.

72
Dom
M1KTA

Another option, If you want to plot smith charts from Touchstone .s1p .s2p files, Simsmith also does this. It is Free. <>
I am eagerly hoping someone integrates this new nanoVNA to output document format like Simsmith, and Zplots type functionality. <> Right now, all we have is screen captures.

Thanks,
David
W0IM

Fit a RCA/0.1" pins/BNC/SO239/SMA (depends what freq range and what is to
hand) to either side of a pcb and the DUT (Device Under Test) in between.

I looked for BNC with 0.1" spacing, but so far found only this:

Do you have any gnuplot code which can import a Touchstone file and plot it on the Smith Chart?

I do, now. Having only this morning first looked at Touchstone S1p files,
I discovered that they are already in gnuplot format,
which seems unlikely mere coincidence.

Regardless, integrating Smith chart format with Touchstone plots
required learning about gnuplot's `set table` command.

Attached are the necessary files
* "smithgrid.p" is loaded >>one time only<< to generate 3MB file "smithgrid.dat"
- "smithloop.p" is called by "smithgrid.p".
- Once "smithgrid.dat" is generated, neither are needed again.
* "smithlabel.p" is called by "plotsmith.p" to format and label charts.
* "plotsmith.p" calls * "smithlabel.p", draws the grid using "smithgrid.dat"
and also plots S11 for any included S1p files.
- multiple copies of "plotsmith.p" may be wanted for various S1p file comparisons.

The reason anyone might want to bother with all this is because
gnuplot makes it pretty easy to plot multiple S1p files on a single Smith chart.

Gnuplot has a command line:

C:\Users\ormpoa>gnuplot

G N U P L O T
Version 5.1 patchlevel 0 last modified 2017-04-18

Copyright (C) 1986-1993, 1998, 2004, 2007-2017
Thomas Williams, Colin Kelley and many others

gnuplot home:
mailing list: gnuplot-beta@...
faq, bugs, etc: type "help FAQ"
immediate help: type "help" (plot window: hit 'h')

Terminal type is now 'windows'
Options are '0 color solid butt enhanced standalone'
Encoding set to 'cp1252'.
gnuplot> load 'smithchart.p'
gnuplot> replot "BNC.s1p" u 2:3 w l title "50 Ohm BNC S11"
-------------------------------------------------------------------------------------
Replacing "BNC.s1p" at that last prompt will plot S11 from whatever Touchstone files you have.
Replotting with more files draws them all on a single chart, facilitating comparisons.

On Thu, Oct 3, 2019 at 05:43 PM, Dr. David Kirkby from Kirkby Microwave Ltd wrote:

I am not saying that the Chinese board is totally useless, but for a PCB
with connectors that have quite a limited lifetime, and a small number of
cheap components, it seems quite expensive to me.

yes, exactly. The price is inadequate very expensive. The real price for such board is 2-5 usd. But they sell it for 30 usd, this is crazy price for the bord with just a connectors with no elements, and these connectors are rated for 20-time use. That's crazy.

If you are waiting to get another nanoVNA, you can get this when it is available on ebay or aliexpress. I got mine from Taobao direct.

But you need to solder in the connectors and the components.

But the Taobao website is in foreign.

On 15 October 2019 at 22:03 SM Ling <sm.ling11@... mailto:sm.ling11@... > wrote:


If you are waiting to get another nanoVNA, you can get this when it is available on ebay or aliexpress. I got mine from Taobao direct.

But you need to solder in the connectors and the components.

Nigel A. Gunn, 1865 El Camino Drive, Xenia, OH 45385-1115, USA. tel +1 937 825 5032
Amateur Radio G8IFF W8IFF and GMRS WRBV701, e-mail nigel@... www

On Tue, 15 Oct 2019 at 00:09, Oristo <ormpoa@...> wrote:

Do you have any gnuplot code which can import a Touchstone file and plot

it on the Smith Chart?

I do, now. Having only this morning first looked at Touchstone S1p files,
I discovered that they are already in gnuplot format,
which seems unlikely mere coincidence.

You are obviously a much more competent gnuplot user than me. I like it the
fact that I can use it non-interactively. The calibration kits I sell come
with about 10 graphs showing various plots such as the properties of
calibration standards, the verification attenuator etc. Manually plotting
that lot would be extremely time consuming and error prone, but being able
to generate all the PDF plots from a single unix shell script makes the
process much easier.

--

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