开云体育

See /g/nanovna-users/topic/34079496#3464

I tried my nanovna as a spectrum analyzer and it is interesting.? Amplitude isn't calibrated.? I measured my signal generator and it shows me two responses fairly close together; I verified on my 'real' SA that there is only one signal.? But it could be handy in some cases.? It showed me sidebands of the signal with AM and FM, for instance.? I kept the input signal down around -25 dBm.
Bob

Hi Larry -

When you click the DFU menu button, you get the next menu with 2 items:
Reset and Enter DFU and Cancel.

OK, I never dared press DFU
and anyway added a slide switch for hard DFU,
too often required for hangs..

The full word:. Calibration is a switch that can be inverted text
to show calibration is being applied,
or normal text to show calibration is not being applied.?

OK, I see "CORRECTION", not "Calibration"

How often do you turn it on or off?

Maybe raw data helps understanding impact of shielding and layout changes?

I hope there will be no objection to me sharing

HTML is in public domain

I wanted a printed chart that I can hang on my wall so I changed the color scheme. I hope there will be no objection to me sharing an ink-saving chart.

gin & pez @ arg;

I am comforted that I seem to be approaching a conceptual understanding of your work. It has elevated my interest.

I am responding to your question with an expanded definition that is intended to enable the separation of the hardware and software components of “Any” VNA measurement.

More precisely, any VNA measures amplitude vs. frequency, and either measures or computes phase in accordance with the architecture of its design, and then performs the mathematics required to yield a result that is declared the complex relationship between a power generated by a source and the power either passed, attenuated/absorbed, or amplified (S21, S12,... Smn, Snm) through a device under test (DUT) or load, and/or the complex relationship between a power generated by a source and the reflected/rejected power at the injection port of the device under test (DUT) or load (S11, S22,... Snn ).

These complex relationships, called Scattering parameters and expressed as transmission and reflection coefficients respectively, are then compared to a normalized set of measurements made of a set of reference impedance standards; the result of which is then used to compute the parameters of influence to transmission, and absorption or reflection by a device under test (DUT).

In the context and spirit of your question as I believe it to be, your statement defines the “hardware” requirements of any VNA measurement system, and we are in agreement on this point. To that end, the primary task of Any VNA is to output a frequency associated complex number pair that is representative of the transmission or reflection coefficient or coefficients it has been configured to provide. Beyond that task, and whether performed internally or externally, all else is derived computationally.

My apologies for not providing the terse response solicited.

--
73

Gary, N3GO

When you click the DFU menu button, you get the next menu with 2 items: Reset and Enter DFU and Cancel.?
The full word:. Calibration is a switch that can be inverted text to show calibration is being applied, or normal text to show calibration is not being applied.? How often do you turn it on or off???



On Sun, 6 Oct 2019 at 10:12 AM, Oristo<ormpoa@...> wrote: Hi Larry -

I think on the CAL line, reset should be the very first item opposite CAL and
everything else is below. Why? You need to do a reset before you do the rest
of the cal steps.

I totally agree and can rearrange that on the tree..

Leave 'calibration' at the bottom as you rarely use it.

Actually, I calibrate pretty often, nearly every time before
measurement, to consider everything except DUT as "ideal".

Also, as soon as you press Done, you get the save menus, no?

Yes, but my CSS is not good enough for two branches to SAVE
.. but I can duplicate SAVEs!

There is one more entry after the DFU button

I see only BACK and do not bother mapping those.

Thanks for the feedback!

On Sun, Oct 6, 2019 at 05:13 AM, <sean@...> wrote: > ... but the parallel resistance at resonance is effectively the radiated power of the antenna, yes?

Since ohms are obviously not watts, please give us the formula that you are using for that conclusion.

Hi Larry -

I think on the CAL line, reset should be the very first item opposite CAL and
everything else is below. Why? You need to do a reset before you do the rest
of the cal steps.

I totally agree and can rearrange that on the tree..

Leave 'calibration' at the bottom as you rarely use it.

Actually, I calibrate pretty often, nearly every time before
measurement, to consider everything except DUT as "ideal".

Also, as soon as you press Done, you get the save menus, no?

Yes, but my CSS is not good enough for two branches to SAVE
.. but I can duplicate SAVEs!

There is one more entry after the DFU button

I see only BACK and do not bother mapping those.

Thanks for the feedback!

edy255's 0.2.2 ch.hex sadly has tiny font..

Also, touch screen seems much less responsive than Gen Hu releases,
and hung repeatedly (requiring power off/on) when trying to set START stimulus..

... back to NanoVNA-H__900_ch_20191003.dfu

AA version font requires a larger flash, resulting in saving the settings of
the flash address overlaps with the program flash and I will modify the aa
version later.

It eventually hung at power-on for me WITHOUT doing touchscreen calibration,
fortunately after capturing mostly legible menu screens.

Took this opportunity to exercise starbuck5250's DFU-from-Hex message:
/g/nanovna-users/message/4159

...hacked into

edy255's 0.2.2 ch.hex sadly has tiny font..

Hi,
I replaced the cables with much shorter ones, and re-calibrated using these 2 new cables (see attached photos), and I am getting the same results. Not sure the cables interfere with the nanoVNA results. As far as I remember, cables longer than wave length/8, I should worry about transmission line effects. However, in this case, the cables are 10 cm long each, and the subject frequency is 60MHz.

Hi, I am fairly new to RF and have been working in electronics as a hobby for decades, but have recently gone back to school and am working toward an engineering degree, either electrical or mechanical, not sure yet but am getting the math and physics out of the way to go either way. So please forgive any lack of understanding on my part. I am working on a project that needs me to determine the values of a coil antenna that will be used in an RFID device at 13.56MHz, I need to design an impedance matching network for the chip that will run the antenna, so I need to know the resonant frequency, inductance, and parallel resistance, does the nano measure parallel resistance? I am using the nanosaver software which has a field for Rp but the values I'm getting at resonance are very high and inconsistent, this is what I would expect if you were to measure the reactive impedance of the antenna at resonance, but the parallel resistance at resonance is effectively the radiated power of the antenna, yes? In any case, I'm a bit lost as to whether the nano isn't going to measure what I need or whether I'm asking it the wrong questions... Thanks!

Thank you for your response. During SOLT calibration, I included the two black coaxial cables, so I thought that this way, I neutralized any effect of the connecting cables. Can you please elaborate more on the right way to understand the behavior of this inductor using the nanoVNA.

Ok, ya got me. Reading the introductions to the two papers left me going, huh? But I do hope it is easy, and that you do publish a simple method.

36 : Primary AnyVNA Measurements

35 : Straight In The Heart of The Matter - 6 October 2019 :
/g/nanovna-users/message/4177
@Gary O'Neil

Hello Gary,

Well, to start from the beginning, would you clarify for us,
please, if would you unreservedly agree with us on that :

"
Primarily, anyVNA measures
( Amplitude Ratio , Phase Difference )
couples in terms of
Frequency
"
?

Regards,

gin&pez@arg

36

It would seem sensible to add a reciprocal command if at all possible.

Particularly if NanoVNA-H V2 may have no touch screen
or is controlled via BlueTooth or USB from mobile devices
(as now by WebUSB app with recent Android versions)

On Sun, Oct 6, 2019 at 10:49 AM, <erik@...> wrote:

no reciprocal command to upload data from the PC to the nanoVNA

It would seem sensible to add a reciprocal command if at all possible.

Anything to avoid having to physically manually enter long sequences is very desirable, especially as it's only possible to retain a small number of configurations internally.

The ability to reload (or clone) settings when new firmware is installed or the memories are wiped would also be handy.

Regards,

Martin - G8JNJ

Please have a look at the firmware.
The "save" command saves the internally measured calibration data to the internal save location [0-4], recall is the reciprocal command to load calibration data from the internal save location.
The "save" command does NOT upload calibration data from outside the nanoVNA into the nanoVNA
The "data" command downloads data from thenanoVNA to the PC, there is no reciprocal command to upload data from the PC to the nanoVNA