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Sean,
Rune's nanovan-saver program will measure "Q" directly by connecting the matched network and antenna to CH0 and selecting "S11 Quality Factor" in the Display settings.

.Herb

What value did you measure? I just measured the Q of my ZS6BKW antenna system from the shack as 17.6 on 40m.

Hello Oristo;

It is good to know this topic is being followed. I hope there are others more capable and perhaps more patient than I, and I welcome them to please chime in. It may expedite the pace of this journey and bring it to a timely and worthwhile conclusion.

This has been an onion peeling exercise for me, and I am not yet at a point where I can conclude that my understanding has correctly converged. If I do reach that point, I would need to reproduce their results to confirm my understanding is valid. Much of what is being shared appears guarded, and I’m not yet certain my optimism is well founded. The struggle to get this far cautions me away from any supportive conclusions or opinions.

That said; perhaps I’m approaching a steeper slope on the learning curve, a third epiphany will manifest itself, and I will become immediately enlightened. My hope is that it is a sweet onion. :-)

It is my intellectual curiosity and passion for knowledge that fuels my own efforts, but my patience is being tested by the peripheral effort required to assess the merit of their work. I do remain committed and encouraged however.

--
73

Gary, N3GO

Rune,
I spent the day verifying unknown filters in my ham shack and documenting their performance using your new "Analysis" module (Tks !). I attached files earlier for typical high pass and low pass filter analysis screenshots . A typical BPF analysis screenshot is attached. There are four filter types I am familiar with: LPF, HPF, BPF and BSF (Band stop or Band reject), I tried selecting BPF analysis for the BSF chart but of course the parameters were out of bounds and no analysis was performed (see attachment).

I can do a low pass and high pass analysis on the BSF to derive the data for the cutoffs and bandwidth, but it would be more convenient if you would add BSF to your analysis module.

Best regards,

Herb

is there any info on measuring the Q of a network and antenna? I set up an S21 test using the matched network and antenna on CH0 and a short coil on CH1, looking at the LOGMAG trace for CH1 I measured the -3dB drop bandwidth and calculated the Q, it was quite a bit lower than what I anticipated though, so I'm wondering if the Nano will work this way or if there's fault in my methodology.

On Tue, 8 Oct 2019 at 23:28, Gary O'Neil <n3go@...> wrote:

Here’s a suggestion to mull over… Suppose a second nanoVNA group be
initiated called “NanoVNA for Beginners”, or “New to NanoVNA”

I don’t think splitting into two will be sufficient. From what I understood
from the group owner around a week ago, the number of subscribers was
showing no signs of tailing off.

I think we need to reduce the traffic still further. These were my
suggestions. I see someone else mention purchasing. That would seem
sensible too.

*1) Beginners* I suggest this because I believe any new owners, especially
if they have never used a VNA before, who are going to get overwhelmed by
discussion of firmware changes, NanoVNA-Saver, the mathematics of
measurement uncertainties etc.

*2) Firmware development*

*3 Programming and remote control* - for software like NanoVNA-Sharp,

*4) Advanced applications* *& technical discussion *

*5) Calibration and error correction*

*6) General Use*
--
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

I downloaded v1.1 of the Calibration Procedure and all is well until
I get to Note 21.

When I connect the two ports together, my Blue Line is at the very
top of the chart and the readout fluctuates around 10 dB (+/- ~ 1 dB).

Their is a Blue tick mark down one division from the top (left side),
but the line is at the top.

What am I doing wrong ?

Tnx es 73, Dick, W1KSZ

Sent from Outlook<>

Here’s a suggestion to mull over… Suppose a second nanoVNA group be initiated called “NanoVNA for Beginners”, or “New to NanoVNA”

The benefits are subtle but would potentially decimate the traffic (I think) significantly Into two distinct interest areas.

By its title, the new group would attract newbies,.. and of course followed by mostly newbies.

As this group grew out of a common interest in the nanoVNA, the new group would follow suit.

Students learn best, faster, and more efficiently when they learn fro each other. There are valid reasons for this:
All are on approximately equal ground... The teacher/student relationship is blurred.
Intimidation or the fear of judgement from asking perceived stupid questions is reduced.
Learning together leads to better understanding.
Questions are often better understood (and better answered) by those who are at a similar level of understanding.
Both groups overall will be more welcoming of the questions comments and responses since they will, more likely than not be among like minded equally informed participants.





--
73

Gary, N3GO

Kurt,

You are correct. That is the very reason I used a wide-band device. I wanted to know the total power coming out of the port. I was not trying to determine the amount of signal that is being used by the VNA but what is presented to a device under test.

Unfortunately, I don't have access to a good spectrum analyzer. I do have a "calibrated" receiver (SDR Uno - RSP2) which has produced inconsistent results when measuring the output of the VNA through about 40 dB of attenuation. I have used it before to get what appeared to be consistent and correct results. I am still trying to understand what is going on with that approach to measuring the various amplitudes.

--
Bryan, WA5VAH

Rune,

Here you go:

ch> version
0.1.1.1-5-gd609fb2

ch> info
Kernel: 4.0.0
Compiler: GCC 8.2.1 20181213 (release) [gcc-8-branch revision 267074]
Architecture: ARMv6-M
Core Variant: Cortex-M0
Port Info: Preemption through NMI
Platform: STM32F072xB Entry Level Medium Density devices
Board: NanoVNA-H
Build time: Sep 20 2019 - 17:31:03

--
Bryan, WA5VAH

Hello David,
I had heard rumours of there being bad Female-Female adaptors included with
some NanoVNAs. I have a bunch of cheap chinese adaptors of that kind, the
one that came with the NanoVNA, and what I consider a good one from
Amphenol, kindly donated to me.

I calibrated my NanoVNA with the Amphenol one and checked the included
"long" F-F adaptor, and a random one from my drawer.

The included one I received checks out to be very close to the Amphenol
version, at least to 900 MHz. Beyond that I get too much noise to get
really good readings. The random connector from the drawer showed a drop
almost from 50kHz, of about -0.03 dB. As it's very little, and the
connectors were done up by hand, I would tend to conclude that I was just a
measurement uncertainty.

Interesting to see that yours is so much worse.

--
Rune / 5Q5R

On Tue, 8 Oct 2019 at 23:33, Dr. David Kirkby from Kirkby Microwave Ltd <
drkirkby@...> wrote:

I’ve have two NanoVNAs, and both were supplied with a female-female SMA
adapter like on the right. It quite a bit longer than most SMA
female-female adapters. The one on the left is much shorter. There’s
nothing special about the one on the left - it just the first I found when
I opened a drawer.

The photograph of a VNA screen is an HP 8720D VNA. I didn’t perform a fresh
calibration of the VNA, but recalled one previously saved. That was good
enough. The supplied thru, left open has a return loss of 0.368 dB, but I
would expect it to be *much* smaller - certainly under 0.05 dB at 1.5 GHz.
The female-female adapters supplied with my NanoVNAs are particularly
poor.

You may notice a huge dip at 6.42 GHz. Thats some internal resonance. It’s
well outside the range of the NanoVNA, but is indicative of a poor adapter.

There are actually two traces shown on the VNA. One is stored in memory. It
is so close to the zero line you can barely see it, but if you look at the
far right, near 7 GHz, you can just see it dipping below zero due to its
loss

*Experience tells me that the thru supplied with the NanoVNA is very poor.*
If you have a thru that’s physically shorter, it will almost certainly be
better.

Although I don’t show it here, I did put a short on the end of the adapter.
The response looks awful. Essentially the thrus I have been supplied are
the worst I have ever seen. Just about any thru will be better.

Perhaps someone else with a calibrated VNA, who has received a thru like
that on the right, will confirm it is a particularly poor one.



--
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 Tue, 8 Oct 2019 at 22:33, Dr. David Kirkby <
drkirkby@...> wrote:

There are actually two traces shown on the VNA. One is stored in memory.
It is so close to the zero line you can barely see it, but if you look at
the far right, near 7 GHz, you can just see it dipping below zero due to
its loss.

I forgot to say, the trace that’s barely visible is the thru on the left of
the photograph. It’s return loss is very close to 0 dB even at 7 GHz.

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

I’ve have two NanoVNAs, and both were supplied with a female-female SMA
adapter like on the right. It quite a bit longer than most SMA
female-female adapters. The one on the left is much shorter. There’s
nothing special about the one on the left - it just the first I found when
I opened a drawer.

The photograph of a VNA screen is an HP 8720D VNA. I didn’t perform a fresh
calibration of the VNA, but recalled one previously saved. That was good
enough. The supplied thru, left open has a return loss of 0.368 dB, but I
would expect it to be *much* smaller - certainly under 0.05 dB at 1.5 GHz.
The female-female adapters supplied with my NanoVNAs are particularly
poor.

You may notice a huge dip at 6.42 GHz. Thats some internal resonance. It’s
well outside the range of the NanoVNA, but is indicative of a poor adapter.

There are actually two traces shown on the VNA. One is stored in memory. It
is so close to the zero line you can barely see it, but if you look at the
far right, near 7 GHz, you can just see it dipping below zero due to its
loss

*Experience tells me that the thru supplied with the NanoVNA is very poor.*
If you have a thru that’s physically shorter, it will almost certainly be
better.

Although I don’t show it here, I did put a short on the end of the adapter.
The response looks awful. Essentially the thrus I have been supplied are
the worst I have ever seen. Just about any thru will be better.

Perhaps someone else with a calibrated VNA, who has received a thru like
that on the right, will confirm it is a particularly poor one.



--
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

Hi David -

If you are changing menus,

You have reached a wrong number;
I wrote only

You could request a firmware change on GitHub, e.g.:

If you are changing menus, could you make the VNA back button loop around if using the switch. For example, if you are in a menu item labeled back, if you press left switch, it goes up one item, and if you press right switch, it loops back around to the first item in the menus. The jog switch is sometimes not as responsive, especially if you have multiple listed items.
Thanks,
David

Do a search in this group for "Place To Buy".

I caught a YouTube video on these and I am very interesting in getting one for my shack however I know next to nothing about them. I have several antenna analyzers for my ham radio equipment and these look like they could be an interesting tool. I have looked on Amazon and there are a number of these with different names and models. They range in price from $35 to $80. How do I determine which ones are good and which are bad?

My Youtube channel is hamrad88 and my name is Tom Stiles

Thanks for your time.

This Feather has lots of goodies:

$15 Particle Xenon has bluetooth

Hi Bryan,
I'm not entirely sure *why* it happens - but I believe edy555 has fixed the
issues in his latest firmware versions. I don't know about Hugen's firmware
versions.

The next version of NanoVNA-Saver will detect the firmware version, and, if
applicable, use the "scan" command edy555 has implemented, which freezes
the display while scanning, but should provide data faster and more
reliably to the PC application.

Speaking of which, since you run a NanoVNA-H version: Could you connect to
it via serial, and run the "version" and "info" commands, and get back to
me with the output of those? I need a sort of database of the different
firmware versions and how to detect them ;-)

--
Rune / 5Q5R

On Tue, 8 Oct 2019 at 21:46, bryburns via Groups.Io <bryburns=
[email protected]> wrote:

Rune,

With all of the recent versions of nanoVNASaver (0.0.11, 0.0.12, 0.1.0,
0.1.1) I have been occasionally getting a pure white screen on the nanoVNA
while making measurements using nanoVNASaver. I can continue to get good
data from the device in nanoVNASaver once this happens; however, I see just
a white screen on the display of the nanoVNA itself. I do not see this
with other software that communicates with my device. I am not sure where
the problem may be. This may be a bug in my firmware
"NanoVNA-H__900_ch_20190924.dfu." Has anyone else reported this?

To restore the real-time screen on the nanoVNA I have to disconnect
nanoVNASaver, restart nanoVNA, and then reconnect nanoVNASaver to the
device.

--
Bryan, WA5VAH

Hi Bryburn
Using a wideband power meter (you did not specify what device you used) will not be able to filter out the harmonics signal amplitude. For that purpose you need a selective power meter or a well calibrated spectrum Analyzer. The fundamental signal hawing the highest power level is always present at CH0. Maybe some highpass filters can filter out the fundamental but accuracy will be questionable as when measurement of 3. Harmonic the 5. and higher will be present also.
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af bryburns via Groups.Io
Sendt: 8. oktober 2019 18:43
Til: [email protected]
Emne: [nanovna-users] Power output from CH0 of the nanoVNA as a function of frequency

Folks,

For some measurements it is important to know how much power is coming out of CH0 on the nanoVNA. I have seen some data elsewhere in this forum and a few spectrum analyzer pictures with max hold enabled. However, I have seen nothing that showed the information I sought. So, I created a set of measured data over the full range of frequencies from 1 MHz to 900 MHz and plotted it as shown in the attached graph, "nanoVNAOutputPower.jpg."

I connected the nanoVNA to the power meter using a very wide-band 10-dB pad to ensure the load was consistent and removed the loss in the pad from the power measurements. The data was collected every 1 MHz from 1 MHz to 30 MHz, every 10 MHz from 30 MHz to 350 MHz, every 25 MHz from 350 MHz to 450 MHz, and every 50 MHz from 450 MHz to 900 MHz. All data was collected in CW mode.

For me, there were a few surprises in this data. I have read that the maximum power out of the device should be -9 dBm or less. This is true over the range of frequencies below 300 MHz. As you can see in the graph, I observed more power coming out of CH0 with CW frequencies above 300 MHz.

I was surprised to learn that for frequencies above 300 MHz, the 3rd harmonic is always assumed in CW mode. This is evident in the power levels shown in the attached graph. I confirmed with a fast oscilloscope that this is indeed the case. When 750 MHz is set, a 250 MHz waveform is coming out of CH0. Perhaps the reasons for this in the firmware is that it produces more power at 750 MHz than using the 5th harmonic and setting the fundamental to 150 MHz. In fact, the output amplitude at the fundamental frequency is increased above 300 MHz and never gets back down to the level I observed at 1-30 MHz. The maximum power I measured was a little less than -7 dBm decreasing to a little more than -10 dBm at 900 MHz as the set frequency. I have read that the 5th harmonic is used above 600 MHz for swept measurements; however, that is not what I saw in the CW data. I assume this is an artifact of the CW measurement.

Over the range from 1 to 300 MHz, I notice that the change in output power I saw (about 9 dB) is consistent with the change in the noise floor for S21 measurements when the ports of the VNA are terminated in loads. A copy of S21 with both ports terminated on my nanoVNA using nanoVNASaver 0.1.0 set for 5 sweeps from 50 kHz to 900 MHz and 20 averages is also attached, "S21 NoiseFloor.png." Clearly, we cannot be very precise with this type of noise floor data but I think it is consistent with the reduction in power out of CH0 I observed from 50 kHz to 300 MHz. So, I really do think there is about a 9-dB variation in the output power on CH0 from 1 to 300 MHz. At frequencies above 300 MHz the noise floor level continues to increase so the increase in power from CH0 must compensate for the use of the third harmonic pretty well in my VNA. I do see a substantial change in the noise floor below 600 MHz. I had thought this should happen at 600 MHz not below 600 MHz.

--
Bryan, WA5VAH