开云体育

Thats insteresting

Thanks

Martin
N6QLH

On Sat, Mar 5, 2022, 1:41 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Sat, Mar 5, 2022 at 02:57 AM, David Wilcox K8WPE wrote:

Can someone explain why my YouKits FG 01 and RigExpert A600 (and even my

old

MJF 269) analyzers don’t need calibration every time I use them compared

to

the NanoVNA? What is the difference in the operating firmware or actual
operation?

In the “old days” I never had to calibrate anything when tuning my
antennas with my GDO or noise bridge? Ha!

The NanoVNA is a two port Vector Network Analyzer that is capable of much
better accuracy than any of the other devices you mentioned. It is also a
more complicated instrument with more features. The best results are
obtained when you calibrate for the range of interest because this creates
a good reference plane and the best instrument calibration. However you
could use the NanoVNA out-of-the box or by calibrating once for the widest
frequency range and storing that in slot 0 for future measurements. You
could then zoom to the frequency range of interest and get as good or
better SWR and RL measurements than the other instruments you mentioned.
For complex impedance measurements calibration is required for the best
accuracy.

The devices you mentioned were calibrated at the factory and this is
sufficient for making RL and SWR measurements. For complex impedance
measurements they are not that accurate out-of-the box.

The MFJ 269 has a difficult calibration procedure that the user can
perform and this will give better performance than the usual poor factory
calibration. I know because I did my MFJ-259B which is an earlier version
of the 269. Unfortunately the calibration is only done on the RF drivel
level and the bridge resistors and does not do anything about the other
sources of error in the device. The RL and SWR are acceptable on this
device but the complex impedance is not great and you don't know the sign
of the reactance.

I don't know about the YouKits FG 01 but I can tell you about the
RigExpert RigExpert A600. It is a one port VNA and comes factory
calibrated for the full frequency range and has this cal data stored in the
instrument. However the device is capable of SOL calibration by the user
and the manual states than this should be used for precise measurements.
You can save the user cal data and switch between it and the factory
default.

In this group we often see people questioning why the operation of the
NanoVNA requires more effort and knowledge than Antenna Analyzers, GDO's
and noise bridges that are also used for tuning antennas. The reason is
that A VNA is a much more powerful instrument and requires more training
and care in its use. Entry level VNA products cost thousand of $$ only a
few years ago but the price has dropped to where hobbyists can purchase
one. But just because it is low-cost does not mean that the skill level to
use one properly has dropped as well.

These handy devices are handy to own, fun to use and worth the effort to
learn how to use in my opinion.

Roger

On Sat, Mar 5, 2022 at 02:57 AM, David Wilcox K8WPE wrote:

Can someone explain why my YouKits FG 01 and RigExpert A600 (and even my old
MJF 269) analyzers don’t need calibration every time I use them compared to
the NanoVNA? What is the difference in the operating firmware or actual
operation?

In the “old days” I never had to calibrate anything when tuning my
antennas with my GDO or noise bridge? Ha!

The NanoVNA is a two port Vector Network Analyzer that is capable of much better accuracy than any of the other devices you mentioned. It is also a more complicated instrument with more features. The best results are obtained when you calibrate for the range of interest because this creates a good reference plane and the best instrument calibration. However you could use the NanoVNA out-of-the box or by calibrating once for the widest frequency range and storing that in slot 0 for future measurements. You could then zoom to the frequency range of interest and get as good or better SWR and RL measurements than the other instruments you mentioned. For complex impedance measurements calibration is required for the best accuracy.

The devices you mentioned were calibrated at the factory and this is sufficient for making RL and SWR measurements. For complex impedance measurements they are not that accurate out-of-the box.

The MFJ 269 has a difficult calibration procedure that the user can perform and this will give better performance than the usual poor factory calibration. I know because I did my MFJ-259B which is an earlier version of the 269. Unfortunately the calibration is only done on the RF drivel level and the bridge resistors and does not do anything about the other sources of error in the device. The RL and SWR are acceptable on this device but the complex impedance is not great and you don't know the sign of the reactance.

I don't know about the YouKits FG 01 but I can tell you about the RigExpert RigExpert A600. It is a one port VNA and comes factory calibrated for the full frequency range and has this cal data stored in the instrument. However the device is capable of SOL calibration by the user and the manual states than this should be used for precise measurements. You can save the user cal data and switch between it and the factory default.

In this group we often see people questioning why the operation of the NanoVNA requires more effort and knowledge than Antenna Analyzers, GDO's and noise bridges that are also used for tuning antennas. The reason is that A VNA is a much more powerful instrument and requires more training and care in its use. Entry level VNA products cost thousand of $$ only a few years ago but the price has dropped to where hobbyists can purchase one. But just because it is low-cost does not mean that the skill level to use one properly has dropped as well.

These handy devices are handy to own, fun to use and worth the effort to learn how to use in my opinion.

Roger

Mine is different

Mine flashes while charging, and then turns a solid red when fully charged.

The light going out makes no sense to me. How would you know the difference from fully charged, or it lost connection and is not getting any power now?

Joe

Thanks for all the replies. The red light finally went out after charging for another 4.0 hours, so I guess it is fully charged now. Apparently in my unit, "Red" means charging and no LED means "fully charged." So far, so good with the unit.
Tom, K4YAZ

Hello Tom, the NanoVNA-H rev3.6 red LED is on to indicate charging and off to indicate charging is complete.
The charging current of NanoVNA-H rev3.6 is about 250mA, and it may take 6 hours to fully charge the battery, the charging current may drop when it is almost full, and the actual charging time may be longer.

Fransesco,

Thanks for the site and reminder.

Dave K8WPE (also a geriatric memory at 77)

David J. Wilcox’s iPad

Please read this page: *On the "OLD DAYS" the calibration was necessary like today you needed to balance the bridge (this came from my geriatric memory).*
*Sent:* Saturday, March 05, 2022 at 10:57 AM
*From:* "David Wilcox K8WPE via groups.io" <Djwilcox01@...>
*To:* [email protected]
*Subject:* Re: [nanovna-users] "Zero calibration" (or "no calibration") question
Can someone explain why my YouKits FG 01 and RigExpert A600 (and even my old MJF 269) analyzers don’t need calibration every time I use them compared to the NanoVNA? What is the difference in the operating firmware or actual operation?

In the “old days” I never had to calibrate anything when tuning my antennas with my GDO or noise bridge? Ha!

Dave K8WPE

David J. Wilcox’s iPad

Can someone explain why my YouKits FG 01 and RigExpert A600 (and even my old MJF 269) analyzers don’t need calibration every time I use them compared to the NanoVNA? What is the difference in the operating firmware or actual operation?

In the “old days” I never had to calibrate anything when tuning my antennas with my GDO or noise bridge? Ha!

Dave K8WPE

David J. Wilcox’s iPad

On 5/3/22 06:03, Miro, N9LR via groups.io wrote:

Based on my very limited knowledge of this technology, calibration does "only" two things - accounts for t-line losses, and compensates for the effect of the t-line electrical length ("unrotates the complex impedance vector"). If I'm willing to accept lack of compensation for losses in the t-line, and also only need S11[dB]/SWR, and don't "care" about accurate (or even indicative) values of complex Z. If differences between individual nano's are minimal, and that does not significantly drives the need for calibration, I'd really like to have a single button somewhere in the menu saying "click here to SOL at S11" :)

Your requirement appears to be incoherent. Initially you said:

what is the quickest way to get calibration that will get me going quickly, without the need for SOL?

Now you're saying:

I'd really like to have a single button somewhere in the menu saying "click here to SOL at S11" :)

The answer to your initial requirement is to perform the calibration at your device ports as usual and save it into slot 0. That way, when you turn your device on, it's calibrated in a rational default which also happens to be what you've asked for and is about as quick an answer as you're going to get.


Your revised requirement no longer seeks "the quickest", but instead "single button". Presumably this is because you want the power-on default configuration to be for some other setup (you've mentioned other purposes without identifying them) and you want this "at the terminals" configuration to be available not by default at power-on, but readily accessible.

Is that a correct expression of your requirement? If so, presumably storing the at-the-ports calibration in any slot other than 0 is precisely what you're asking for. Then when you want to use it, you simply load the calibration from whichever slot you chose for this purpose. Does this address your requirement? Are you perhaps suggesting that the few seconds that it takes to get to a numbered calibration slot and retrieve it is a material inconvenience?


More broadly:

I see that as a perfectly realistic request, if (IF!) there are no known variations between individual devices when it comes to SOL at S11.

Well, yes, of course there are variations between individual devices, both at manufacture and throughout their service life. Whether you care about them depends upon your application of course. e.g. For most amateur radio uses, it is not necessary to recalibrate a digital multimeter throughout its service life, but that's not true for a lot of commercial/industrial lab uses. Whether the variations in your particular NanoVNA concern you will depend very much upon what you're doing. It's not even enough to say "for amateur use" as while for HF antenna evaluation it's probably negligible, for tuning a duplexer (as for an amateur band 2 m repeater) some precision is required.


- Roland 9V1RT

On Fri, Mar 4, 2022 at 07:43 AM, Miro, N9LR wrote:

Now question - what happens when I "reset calibration" on nano - will that in
effect be equivalent to calibrating nano directly at the port?

If not, what is the quickest way to get calibration that will get me going
quickly, without the need for SOL?

There are numerous articles and videos available which discuss why a VNA requires calibration. A quick Google search will provide articles in whatever technical depth you want.

I suggest that you just calibrate your NanoVNA right at the S11 port for the widest frequency range that you operate. Save it to slot 0 and you are done. On power up it will use the calibration in slot 0 and you can make your measurements. No additional calibration is necessary in most cases This was suggested by Colin McDonald in his reply to you as well. You can even zoom into the frequency range of interest and many of the NanoVNA products will interpolate for you. The SWR and Return loss will be good enough for tuning purposes and for HF the length of any pigtails will not make a significant difference in the results. I posted some detailed reports on how well this works for measuring SWR of HF and VHF antennas in this group a while ago.

The SWR and Return Loss will be worse at the antenna than measured at the end of your feedline. If you want an estimate of Return Loss or SWR at the antenna and you know (or can estimate) the attenuation of the cable it is easy to calculate the Return Loss at the feedpoint. By knowing the feedpoint RL you can calculate the SWR or look it up on one of the SWR-RL conversion tables. Or you can use this handy chart.

Roger

The LED should flash red while charging, and stays on steady red when
fully charged. 90 min of use may not have discharged it very much.

On Fri, Mar 4, 2022, 2:21 PM Tom C. via groups.io <uuhamfl@...>
wrote:

I am a new owner of an Aursinc NanoVNA-H, HW Version 3.6
Charged it for 4 hours out of the box, but only RED LED solid.
Used it for 90 minutes matching mobile HF antenna; seems to work fine.
Now to charge it after use. Still getting only RED LED solid. (?)
Not sure about this indication or if it is charging.
Any ideas?

On 3/4/22 2:03 PM, Miro, N9LR via groups.io wrote:

On Fri, Mar 4, 2022 at 03:34 PM, Colin McDonald wrote:

It's a specific tool. One must use that tool as intended or it is no longer
useful.

I think we all agree with that :). My question is how to make it more useful (or easier to use) without breaking the bank. I hope the answer is to have a feature request for one of future releases that will "hardcode" SOL at S11 port, so I get Slot 0 back for other use :) I see that as a perfectly realistic request, if (IF!) there are no known variations between individual devices when it comes to SOL at S11.

You can turn calibration off and it will use no slot. But there *are* variations between units. At least between the two I have.

Based on my very limited knowledge of this technology, calibration does "only" two things - accounts for t-line losses, and compensates for the effect of the t-line electrical length ("unrotates the complex impedance vector"). If I'm willing to accept lack of compensation for losses in the t-line, and also only need S11[dB]/SWR, and don't "care" about accurate (or even indicative) values of complex Z. If differences between individual nano's are minimal, and that does not significantly drives the need for calibration, I'd really like to have a single button somewhere in the menu saying "click here to SOL at S11" :)

It's a bit more complex than that? - It also compensates for the non-ideal "output impedance" and the non-ideal "input impedance" of the VNA.? One can, at some level think of it as a boiling down to multiplying by some complex number (phase and loss) for each point.

I've found the 3 measurements that hams need, SWR, Z impedance and capacitive
reactance to have very little variation between using a wide spectrum
calibration and a narrow calibration that is frequency specific.

I agree! The key problem I have is doing that calibration :) You are right, it's me, not the tool, but if that tool can make me better, or compensate for my shortcomings, why not :)

At HF frequencies, the coax is generally a factor in the antenna system so you
want to measure it along with the antenna for tuning purposes. You don't
necessarily want to calibrate each individual coax as you are trying to
calibrate a portion of the antenna itself at that point which doesn't give a
clear picture of what the radio is seeing at the shack end of the coax.

In general I do agree, but it's not that simple - sometimes I need SWR scan at the side of my RIG, sometimes I want to understand my antenna itself and then I'm willing to do proper calibration wherever needed.

For another thread - attaching a coaxial cable to my new antenna usually changes "everything" - complex Z, radiation pattern, ... That's why all my measurements at the antenna feed point have fairly good "balun" (current balun = CM suppression) that significantly limits the impact of the t-line to antenna "geometry". That's also why measuring at the RIG becomes necessity to understand (measure) potential impact of the t-line and to see what my TX is actually going to see

This is why I have relays at the antenna which can connect short or load, as well as antenna. Then I can calibrate/measure my cable any time I need to.

At the simplest you could use a 4 position switch (like an MFJ4713) - the 4 outputs are: antenna,short, load, open. You can pick which one is the "power off default".

(of course, the sad thing is that the switch costs 3 times as much as the VNA - it might be cheaper to put a 2 position switch at the antenna, and a spare VNA, with a remote access serial port)

I am a new owner of an Aursinc NanoVNA-H, HW Version 3.6
Charged it for 4 hours out of the box, but only RED LED solid.
Used it for 90 minutes matching mobile HF antenna; seems to work fine.
Now to charge it after use. Still getting only RED LED solid. (?)
Not sure about this indication or if it is charging.
Any ideas?

On Fri, Mar 4, 2022 at 03:34 PM, Colin McDonald wrote:

It's a specific tool. One must use that tool as intended or it is no longer
useful.

I think we all agree with that :). My question is how to make it more useful (or easier to use) without breaking the bank. I hope the answer is to have a feature request for one of future releases that will "hardcode" SOL at S11 port, so I get Slot 0 back for other use :) I see that as a perfectly realistic request, if (IF!) there are no known variations between individual devices when it comes to SOL at S11.

Based on my very limited knowledge of this technology, calibration does "only" two things - accounts for t-line losses, and compensates for the effect of the t-line electrical length ("unrotates the complex impedance vector"). If I'm willing to accept lack of compensation for losses in the t-line, and also only need S11[dB]/SWR, and don't "care" about accurate (or even indicative) values of complex Z. If differences between individual nano's are minimal, and that does not significantly drives the need for calibration, I'd really like to have a single button somewhere in the menu saying "click here to SOL at S11" :)

It takes seconds to perform a SOL calibration at the S11 port.

Not always true :) I sometimes need a quick measure when S11 port SOL is not an easy thing to do, and I forget to do it ahead of time :)

I've found the 3 measurements that hams need, SWR, Z impedance and capacitive
reactance to have very little variation between using a wide spectrum
calibration and a narrow calibration that is frequency specific.

I agree! The key problem I have is doing that calibration :) You are right, it's me, not the tool, but if that tool can make me better, or compensate for my shortcomings, why not :)

At HF frequencies, the coax is generally a factor in the antenna system so you
want to measure it along with the antenna for tuning purposes. You don't
necessarily want to calibrate each individual coax as you are trying to
calibrate a portion of the antenna itself at that point which doesn't give a
clear picture of what the radio is seeing at the shack end of the coax.

In general I do agree, but it's not that simple - sometimes I need SWR scan at the side of my RIG, sometimes I want to understand my antenna itself and then I'm willing to do proper calibration wherever needed.

For another thread - attaching a coaxial cable to my new antenna usually changes "everything" - complex Z, radiation pattern, ... That's why all my measurements at the antenna feed point have fairly good "balun" (current balun = CM suppression) that significantly limits the impact of the t-line to antenna "geometry". That's also why measuring at the RIG becomes necessity to understand (measure) potential impact of the t-line and to see what my TX is actually going to see

It is always a good idea to watch the behavior of the various calibration standard traces as you perform a calibration; you can spot an incorrect or damaged standard or poor connection just by the general shape of the trace.
73, Don N2VGU

It's a specific tool. One must use that tool as intended or it is no longer useful.

It takes seconds to perform a SOL calibration at the S11 port. Perform a wide spectrum SOL calibration and save that as a reference point. It'll be close enough for amateur radio antennas.

If you question the accuracy, again it takes a few seconds to perform a calibration at the frequencies you want.

I've found the 3 measurements that hams need, SWR, Z impedance and capacitive reactance to have very little variation between using a wide spectrum calibration and a narrow calibration that is frequency specific.

For instance, a SOL calibration right at the s11 port for 1.8 to 30MHZ shows very similar results to a SOL calibration at the S11 port done for say 14.13 to 14.35MHZ using the same antenna and coax to measure.

Any variation is as likely to be at the antenna as at the NanoVNA.

At HF frequencies, the coax is generally a factor in the antenna system so you want to measure it along with the antenna for tuning purposes. You don't necessarily want to calibrate each individual coax as you are trying to calibrate a portion of the antenna itself at that point which doesn't give a clear picture of what the radio is seeing at the shack end of the coax.


Regards

Colin

On 3/4/22 12:22 PM, Miro, N9LR via groups.io wrote:

On Fri, Mar 4, 2022 at 12:26 PM, Kenneth Hendrickson wrote:

calibrate at the end of the coax which will attach to the antenna

Easier said then done :)

* have limited number of calibration slots

If you're using PC software - it's a file.

* don't have an easy access to measure some of coaxials (previous installations, difficult to lower antenna, helping a friend, ...)

Definitely the problem.

* HAMs often change feeds on a whim and don't remember to recalibrate

Who me? Never do that. No way. :)

* ...
I have all kinds of calibration standards, that's not a problem, but "doing" calibration ahead of time (and being able to store it on nano) is often a challenge

On Fri, Mar 4, 2022 at 02:51 PM, Stan Dye wrote:

Once you do an SOL calibration at the nano pigtails, over your frequency
range of interest, save it to memory 0. The nano initializes to this when
you turn it on, so you don't need to repeat the SOL each time.

The point of Kenneth's (rightful) response was "calibrate each of your coaxial runs to antenna, recall that later. With more then 4 antennas that's not possible due to nano's limit to slots

On the other side, calibrating at the port is what I do, but I expect that can be done by a firmware/hardcoded value and recalled as needed. I use slot 0 for some other stuff sometimes :)

Once you do an SOL calibration at the nano pigtails, over your frequency
range of interest, save it to memory 0. The nano initializes to this when
you turn it on, so you don't need to repeat the SOL each time.

On Fri, Mar 4, 2022 at 12:23 PM Miro, N9LR via groups.io <m_kisacanin=
[email protected]> wrote:

On Fri, Mar 4, 2022 at 12:26 PM, Kenneth Hendrickson wrote:

calibrate at the end of the coax which will attach to the antenna

Easier said then done :)

* have limited number of calibration slots
* don't have an easy access to measure some of coaxials (previous
installations, difficult to lower antenna, helping a friend, ...)
* HAMs often change feeds on a whim and don't remember to recalibrate
* ...
I have all kinds of calibration standards, that's not a problem, but
"doing" calibration ahead of time (and being able to store it on nano) is
often a challenge

On Fri, Mar 4, 2022 at 12:26 PM, Kenneth Hendrickson wrote:

calibrate at the end of the coax which will attach to the antenna

Easier said then done :)

* have limited number of calibration slots
* don't have an easy access to measure some of coaxials (previous installations, difficult to lower antenna, helping a friend, ...)
* HAMs often change feeds on a whim and don't remember to recalibrate
* ...
I have all kinds of calibration standards, that's not a problem, but "doing" calibration ahead of time (and being able to store it on nano) is often a challenge