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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.

My device is Nanovna-F and I couldn't make dfu work with it.

Even though this looks to be a solution to my problem, I am using Nanovna-F and I couldn't find dfu working with my device.

On Tue, Oct 11, 2022 at 02:14 PM, Brian Beezley wrote:

Mikek, I think this has gotten too far from the realm of NanoVNAs.

OK, no problem. Anyone that wants to email me about my last post, please do.
Thanks for the info about measuring Q of a cap, I'm building a circuit between forum exchanges, when
I get that working I'll pull out the 260A and see what I can find out about measuring cap Qs.
Thanks, Mikek
Just got your email 16 minutes ago.

Mikek, I think this has gotten too far from the realm of NanoVNAs. I have sent you several private messages to try to take this discussion off-line, but I've not received a reply. If you want to continue, send me an email. My address is shown where you downloaded the program.

Brian

On Mon, Oct 10, 2022 at 05:53 PM, Brian Beezley wrote:

our antivirus program is probably keeping you from opening the ZIP file. Send
the file to to assure yourself that
it's virus-free and then disable your antivirus program.

I finally got it to download and then opened.
Is the L that is displayed before accounting for distributed capacitance?
Do I add one wire diameter to my core diameter to get "Core Dia" (i.e. center to center)
Do I measure width from center of outer wire to center of the opposite outer wire?
If I do the above and the calculate measured L with distributed capacitance it comes close.
268uh displayed, 238.5uh calculated with distributed capacitance, 237.3uh measured.
True L x C/C+Cd = The measured L
Q is almost 24% higher than I measure.

However, If the Q of my 260A capacitor is 10,000, at 1MHz, that is 0.151Ω, add that to 0.958Ω from the program and we have 1.107Ω.
Q =XL / R(loss)-- 237uh coil at 1MHz is 1491XL / 1.107Ω = 1346Q, this is just below what I measured at about 1380Q.


I got 100pf cap from Digikey that was supposed to have a Q of 10,000, I added it to my minimum 37pf of the 260A,
and found Q dropped just a few points with the 10,000Q 100pf added, telling me my 260A cap is not very much better than the10,000Q fixed cap I added.

Mikek

On Mon, Oct 10, 2022 at 05:53 PM, Brian Beezley wrote:

Measuring large coils can be difficult because they couple to everything,
including the Q meter enclosure and your body. See README.TXT for a simple way
to overcome this problem.

Yes, If I get within two feet of my coil at resonance, I can see the Q start to drop.
I use about 10" of styrofoam to get the coil away from the Q meter, probably not far enough, but
it's the best I can do.
There is a low loss ferrite available that if wound right will get you a Q over 1200 through the BCB.

And into the high 1400s If with contra wound.
Mikek

I'm sure you're right, Jim. I think most experimenters grab whatever is at hand and press it into service as a coil form. No telling what its characteristics really are. At one time or another I've used beverage bottles and cardboard boxes. I did find the dielectric constant and dissipation factor for a particular cardboard material. It's on the bottom of the dielectric list for a good reason. I expect it too attracts water.

My favorite writeup on wet coils:



I think this kind of loss would be easy to measure with a NanoVNA.

Brian