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The ham-antennas group often discusses antenna modeling using EZNEC and/or 4NEC2,
among others. There is more discussion about those simulators on that group than either of
the NEC groups.

Thanks a lot. I just subscribed to this group and will read the posts. This is probably a solution to my communication difficulties. I'll be sure to keep you posted.
--
F1AMM Fran?ois

-----Message d'origine-----

De la part de Dave Daniel
14 octobre 2022 11:15

4nec2 is much less efficient than EZNEC. EZNEC offers, in particular, a very good antenna geometry editor. EZNEC "opens" .NEC files but unfortunately they are only rarely compatible because 4nec2 authorizes variables in GW cards (lines) which EZNEC does not support.

Now that EZNEC is "free", we must abandon 4nec2 as we abandoned MMANA-GAL Basic for 4nec2.
--
F1AMM Fran?ois

There is also a 4NEC2 group which is slightly (but not mgch) more active than the EZNEC group.

The ham-antennas group often discusses antenna modeling using EZNEC and/or 4NEC2, among others. There is more discussion about those simulators on that group than either of the NEC groups.

DaveD

As an alternative, you might take a look at 4nec2.

There is some information about the 4nec2 application and the classes our
Rochester NY Amateur Radio Service club is running for Antenna Modeling
just 4nec2 on our website, rochesterham.org. The instructor said he is
familiar with EZNEC as well.

73

Joe AD2DB

Thank you for your reply. I understand the situation better and I was right to ask the question here.

I guess HFSS and CTS are unaffordable on QSJ side by amateurs.

It's funny to see that a hobbyist now has a VNA that cost a fortune 50 years ago and to see this transfer of wealth to the software.

Question :
For an amateur, the solution is good, at best, with EZNEC or are there other solutions (free).
--
Fran?ois

Hi Francois
I worked with Roy at Tektronix 25 years ago and have been using ELNEC then EZNEC for 28 years.
Good to see there is a EZNEC group, I wondered about that since Roy is 100% out of the software game.
Yes, have downloaded the Pro version he has made open software, and yes, that is quite a manual.
I understand the low activity.? Really serious antenna designers have moved on to HFSS and CST type programs.
Kent WA5VJB

Hello

I carefully follow the exchanges on /g/nanovna-users I see that many are also tinkering with the antennas.

I'm taking my first steps with EZNEC. I translated Roy W. Lewallen's documentation into French by redoing the exercises he prescribed. Roy's document is huge because it includes a lot of modeling tips based on his experience. As the software remains in English, I have integrated many (partial) screenshots into the translation.

I'm writing tutorials (in French) that don't follow Roy's pedagogical progression. I do this mainly for me in order to make progress in my learning a reality.

I registered on /g/eznec This group does not work. There is almost no trading (interchange ?) on it (September 3/September 15). I asked a question there on September 23 but did not get a satisfactory answer.

- Do you use EZNEC?
- Do you know of a newsgroup that would work as well as nanovna-users but deal with EZNEC?
--
F1AMM (Fran?ois)

On Thu, Oct 13, 2022 at 01:22 PM, <aackthpt@...> wrote:

...if you are using them or Smith charting to do the tuning
you can electrically "move" the calibration plane using the method shown in


...

This video plus your description of how you did it is just what I was looking for.

(also the other replies in this thread are really useful too)

Thanks, folks!

I honestly do not have a clue what the hell I did but I figured it out? HAHA. I removed everything and started from the beginning again. I really don't like this result because I cant explain myself and this does no good to anyone who comes across this thread but I will not complain. Now I have to select the firmware to go with..

Thus is insteresting

On Thu, Oct 13, 2022 at 12:52 PM Michael Black via groups.io <mdblack98=
[email protected]> wrote:

The only way to properly measure an antenna is at the antenna initially.
Once you're happy with the antenna the coax can mostly be ignored and you
should NOT change your antenna based on any measurements done with the coax
connected. Coax has it's own inductance and reactance and impedance which
you cannot change. This is also why tuners are best placed at the antenna
and not at the rig as the tuner can get misled by common mode also and coax
effects.
If the VNA allows proper calibration you can calibrate your coax by
putting the open/short/load at the end of the coax where you are hooking up
the antenna. Then when you measure at the rig side you will see just the
antenna (plus whatever common mode is coming back at you) and it should
like the measurement done at the antenna. To see if common mode is
affecting your measurement you can add a 1/4 lambda length coax jumper and
see if your VNA answer changes. If it does than common mode is affecting
your measurement and you can pretty much ignore what the VNA says at that
point.
Adapters don't cause a lot of problems so an SMA/PL-259 or SMA/UHF adapter
should be OK so at least you are using the same loads all the time (there
is (or rather should be) some minor variation between loads).
What you should look for is tuning at the antenna for j0=0 (resonance) --
the frequency where j0=0 occurs should not change with the coax even if
common mode occurs. The rest of the curve might change though. The
reason is that you don't get much common mode at the resonant frequency.
I just went through this exercise tuning a 6M beam where we found a
Cushcraft 6M4EL had the wrong measurements in the manual. Once we got the
antenna tuned properly (adjusting the feed element for frequency and D1 for
impedance) we were able to get an SWR of 1.07 and 600KHz width < 1.5. Once
we connected the coax the tuned frequency stayed the same but the SWR
increased a bit to 1.12 which is expected due to the added connectors. A
proper choke at the antenna suppressed common mode on the non-resonant
frequencies so the VNA smith chart didn't change much with the coax added.
Mike W9MDB
On Thursday, October 13, 2022 at 02:10:17 PM CDT, Connie Stillinger
via groups.io <stillinger@...> wrote:

Hi -- I would like to use the NanoVNA for measuring and adjusting
antennas in the field for relatively casual POTA and other portable ham
radio activities (e.g. tuning the loading coil on a vertical; or tuning
wire lengths on a dipole or EFHW; etc).

My antennas' feed points as well as my feed lines are all either UHF or
BNC, and my radio has a UHF connector.

The problem is that the NanoVNA has SMA connectors and only an SMA
calibration set. In order to measure my antennas and cables I need to
use adapters.

Do I need to acquire or make BNC and UHF calibration sets for this kind of
field antenna measurement? Or is calibration using the SMA cal set at
all useful for this kind of amateur radio activity? I know it's not ideal
but since I'm not looking for a high degree of precision I wonder how bad
the error will be.

How can I measure the error due to the use of adaptors?


Thanks,

Connie

This is the path on my PC:

C:\Program Files (x86)\STMicroelectronics\Software\DfuSe v3.0.6\Bin\Driver\Win10

If you are tuning by SWR only, that won't change due to having the extra stuff between the nanoVNA and the DUT. The values of complex impedance etc will change, though, so if you are using them or Smith charting to do the tuning you can electrically "move" the calibration plane using the method shown in

Here's one way to approach this on an ongoing basis:I did a cal, then put the extension cable onto the nano and worked out its electrical delay and wrote it down. Then did the same for the SMA F-F adapter and for each of my three adapters SMA-BNC/UHF/N. Since I'll usually use the cable, F-F, and one of the adapters I added up the total of those three combinations. That got close, but when I put one of them on it still wasn't quite right, so I played around with the delay setting until I got it as close as I cared to get it back to the original point. In the future I can just recall that cal and apply the electrical delay for that collection of items and know I am seeing reliable results. It's actually really easy once you play with it a bit.

Can you tell me what the name of this file is or can you provide a picture of what I should be looking for? I have opened all of the folders that I have downloaded and again the files in the instructions do not match the files on my computer.

You have to manually install the STM driver - it is in the dfuse package, if running Windows.? (Linux and Mac don't need a special driver).

It will *never* be able to find the driver automagically!

- Tim

--
Tim Dawson

972-567-9360

The only way to properly measure an antenna is at the antenna initially.? Once you're happy with the antenna the coax can mostly be ignored and you should NOT change your antenna based on any measurements done with the coax connected.? Coax has it's own inductance and reactance and impedance which you cannot change.? This is also why tuners are best placed at the antenna and not at the rig as the tuner can get misled by common mode also and coax effects.
If the VNA allows proper calibration you can calibrate your coax by putting the open/short/load at the end of the coax where you are hooking up the antenna.? Then when you measure at the rig side you will see just the antenna (plus whatever common mode is coming back at you) and it should like the measurement done at the antenna.? ?To see if common mode is affecting your measurement you can add a 1/4 lambda length coax jumper and see if your VNA answer changes.? If it does than common mode is affecting your measurement and you can pretty much ignore what the VNA says at that point.
Adapters don't cause a lot of problems so an SMA/PL-259 or SMA/UHF adapter should be OK so at least you are using the same loads all the time (there is (or rather should be) some minor variation between loads).
What you should look for is tuning at the antenna for j0=0 (resonance) -- the frequency where j0=0 occurs should not change with the coax even if common mode occurs.? The rest of the curve might change though.? ? The reason is that you don't get much common mode at the resonant frequency.
I just went through this exercise tuning a 6M beam where we found a Cushcraft 6M4EL had the wrong measurements in the manual.? Once we got the antenna tuned properly (adjusting the feed element for frequency and D1 for impedance) we were able to get an SWR of 1.07 and 600KHz width < 1.5.? Once we connected the coax the tuned frequency stayed the same but the SWR increased a bit to 1.12 which is expected due to the added connectors.? A proper choke at the antenna suppressed common mode on the non-resonant frequencies so the VNA smith chart didn't change much with the coax added.
Mike W9MDB

SO!
After almost a year and giving up I've now spent 2 days trying to make sense of this and still failing. I've followed the Beginners guide and when once I download and install "everything" it falls apart. I'm left with an yellow exclamation mark on the STM bootloader icon left in the com and ports tab under device manager, searching for the updated driver I assume is a fail. The files displayed in the figures from the walk through are not what I have on my screen.

This is a windows 11 laptop still. Is there someone who has some patience to help out aside from pasting links to more and more websites and saying click this? I've attached the picture of the unit I purchased.

Hi -- I would like to use the NanoVNA for measuring and adjusting antennas in the field for relatively casual POTA and other portable ham radio activities (e.g. tuning the loading coil on a vertical; or tuning wire lengths on a dipole or EFHW; etc).

My antennas' feed points as well as my feed lines are all either UHF or BNC, and my radio has a UHF connector.

The problem is that the NanoVNA has SMA connectors and only an SMA calibration set. In order to measure my antennas and cables I need to use adapters.

Do I need to acquire or make BNC and UHF calibration sets for this kind of field antenna measurement? Or is calibration using the SMA cal set at all useful for this kind of amateur radio activity? I know it's not ideal but since I'm not looking for a high degree of precision I wonder how bad the error will be.

How can I measure the error due to the use of adaptors?


Thanks,

Connie

On Wed, Oct 12, 2022 at 09:26 AM, G8DQX list wrote:

the *Internet Archive *seems to have captured /The Radioboard/, to be found at
. Wait
for a calendar to show, and then the Archive has various captures at different
dates, so one can go back in time.

Thanks for checking, but as far as I can tell, none of the individual posts are archived

It has also captured the "didn't pay"

message to be found today.

The Crystal Set forum's most recent capture before things went south is at

<

These are after it went South. I think Namecheap.com is trying to sell the URL.

. (the equivalent for the website seems to be

.)

This looks like a page setup by the original founder of TheRadiboard, Dave Schmarder, a few
of the links work, others say account suspended or take you to the wayback machine.
I'm afraid all the info is gone only to be experimented, discovered, built and rewritten in the future.
Mikek

hello everyone!
I have such a problem: the screen of my nanovna v2 was broken. I ordered the same screen from aliexpress and got a big disappointment. The image on the screen is inverted and only half of the screen. I thought that transferring the display to the old board from the broken display would solve my problem, but no, I got exactly the same result. Perhaps someone has experience solving this problem. I ask for help.

Mike,

the *Internet Archive *seems to have captured /The Radioboard/, to be found at . Wait for a calendar to show, and then the Archive has various captures at different dates, so one can go back in time. It has also captured the "didn't pay" message to be found today.

The Crystal Set forum's most recent capture before things went south is at <>. (the equivalent for the website seems to be .)

HTH, 73, Stay Safe,

Robin, G8DQX

P.S: It's possible, likely even, that The Radioboard is awaiting revival on payment of a fee, if someone has the necessary cash.