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Your picture shows you do with 51 points. Did you try with 101 or 201?

Et voil脿 Roger, thanks to you !!

73's jean Marie F5VLB

On 2022-05-31 05:50:-0700, you wrote:

Hi, out of curiosity I've made a measurement of my nanovna H4 stock RG316 cable

I flashed v1.2 last night. Using cal from 2.5-32.5 MHz, 401 p. Changed freq range to 3-5 MHz
I have 3X RG316
3660mm
4580mm
4580mm
One connected M-F, and the other connected M-M, for a total length of
12.820m

Following the user manual...
Mult length X 4 = 51.280

Initial VOP estimate 70% yields frequency
4095164 Hz

So I chose a freq range of 3-5 MHz.
Initial length reported as 13.20m. When I removed a M-M adapter on the end, the length lost 10mm, which is reasonable.
13.2-12.820=0.38 which is significantly off, but VOP is a possible reason.
remove M-M adapter > 13.19m
VOP 70>68 > 12.82m.
So changing the VOP from 0.70 to 0.68 changed the reported length to what I physically measured.

Screen and s1p attached.

The phase might have been more accurate for finding the exact distance, but I just threw this together for example.

Continuing...
I got interrupted for 30 minutes, during which the nVNA was running and charging.
Returning, I reconnected the coax in exactly the same way and at the same location on the bench.
This time reported length is 12.88m, a change of 60mm.
I turned on phase, and moved the marker to the phase change. f = 3.955 MHz, vs my estimated 4.095164. Close enough.

I changed the freq range to 3.8-4.2 MHZ, with the understanding that the new range would use interpolated values.
Orig range 2.5-32.5 MHz = 75 kHz/step.
New range 3.8-4.2 MHz >> 400 kHz, meaning that only 3-4 original cal points are included in the interpolation. At least the target is in the middle of that range.

I recalibrated 3.8-4.2 MHz, 401 p. SOLI.
Length still reported as 12.88m. Phase f = 3.956 MHz.
Screen images and s1p files attached.
Note that changing VOP to 67% >> 12.69m, 69% >> 13.07mm, so this is as close as I can get.

The uncertainties are the changing length reported over time, the actual coax VOP, and the accuracy of the nVNA (see changing length).

I didn't have time to compare with TDR.

~R~
72/73 de Rich NE1EE
The Dusty Key
On the banks of the Piscataqua

Thanks for the link, Roger. I'm going to try using it with NanoVNA App. If
I feel adventurous, I may try fixing the screen. Thanks for your help.
Perry

On Tue, May 31, 2022 at 5:42 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Tue, May 31, 2022 at 02:11 PM, Perry Westberry wrote:

A few days ago, I was able to get the unit into DFU mode and it was
recognized in Device Manager. I installed the latest Firmware and was

still

getting a white screen. At the suggestion of another post, I left the
analyzer off for a few days with the battery disconnected. I powered it
back up today with the results that it now shows in Device Manager and I
was just able to run a calibration through NanoVNA Saver but the screen

is

still white.

This sounds like you may have a defective screen issue. I recall others
had this problem and opened up the unit and checked the solder
connections. Some cured it by gently re-soldering connections.

If you are going to use it as is with a PC program use NanoVNA App. It
will use raw uncalibrated data during calibration while Saver depends on a
calibrated NanoVNA. NanoVNA app also does firmware flashing. If you are
new to nanoVNA app see my previous post on it >>>
/g/nanovna-users/topic/91143866#28096

Roger

Thank you Roger, my friend F5WK Michel followed the procedure and all is working for him. Will do the same today.
Regards Jean Marie

The following files and folders have been uploaded to the Files area of the [email protected] group.

* /user manual and menu maps/nVNA-H4 v4.3_MS firmware 1.2 menu map 0100 AN14.zip ( /g/nanovna-users/files/user%20manual%20and%20menu%20maps/nVNA-H4%20v4.3_MS%20firmware%201.2%20menu%20map%200100%20AN14.zip )

*By:* Rich NE1EE <TheDustyKey@...>

*Description:*
nVNA-H4 v4.3_MS firmware 1.2 menu map 0100 AN14 Initial version of firmware 1.2 menu map

Thanks Rich, that's very helpful for those of us using EXCEL for data manipulation or graphing. Your equations are much tidier than what I was using.
Rudy N6LF

On Tue, May 31, 2022 at 02:11 PM, Perry Westberry wrote:

A few days ago, I was able to get the unit into DFU mode and it was
recognized in Device Manager. I installed the latest Firmware and was still
getting a white screen. At the suggestion of another post, I left the
analyzer off for a few days with the battery disconnected. I powered it
back up today with the results that it now shows in Device Manager and I
was just able to run a calibration through NanoVNA Saver but the screen is
still white.

This sounds like you may have a defective screen issue. I recall others had this problem and opened up the unit and checked the solder connections. Some cured it by gently re-soldering connections.

If you are going to use it as is with a PC program use NanoVNA App. It will use raw uncalibrated data during calibration while Saver depends on a calibrated NanoVNA. NanoVNA app also does firmware flashing. If you are new to nanoVNA app see my previous post on it >>> /g/nanovna-users/topic/91143866#28096

Roger

I'm using the latest version installed a few days ago.
Perry

On Tue, May 31, 2022 at 2:26 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Tue, May 31, 2022 at 06:33 AM, Jean-Marie Polard wrote:

I have a problem with the NanoVNA-H(4) and NanoVNA-App

I can connect it on com5 but it does not read the data and mention
always a number of points error

Does someone has a trick to solve this problem ?

What version of H4 firmware are you using?

The NanoVNA app uses a binary protocol to transfer sweep data. This is
different than the old ASCII protocol that was initially used by the
NanoVNA. If your firmware is over a year old you need to update it.

Roger

Zack.

A few days ago, I was able to get the unit into DFU mode and it was
recognized in Device Manager. I installed the latest Firmware and was still
getting a white screen. At the suggestion of another post, I left the
analyzer off for a few days with the battery disconnected. I powered it
back up today with the results that it now shows in Device Manager and I
was just able to run a calibration through NanoVNA Saver but the screen is
still white.
Perry

On Tue, May 31, 2022 at 4:24 PM Clyde Lambert <clyde.lambert@...>
wrote:

Hello,
Being a past bata tester of FW for this unit, I have dealt with your
problem.
The way I cured it is as follows:
First shut down the NanoVNA.
Remove the back cover.
Using small tweezers or what you ha e short the boot pad to the vcc pad
next to it. While keeping the short, turn on the NanoVNA.
Remove the short, shut the NanoVNA off. Replace the back cover.
Now turn the unit on.
You should be able to re install the new, or old, FW by putting your
NanoVNA in DFU mode via the menu,
I have had to do this several times so, I installed a micro switch to
short the two pins without having to take the unit apart.
Clyde KC7BJE

Then turn the

Hello Roger,

Op di 31 mei 2022 om 19:40 schreef Roger Need via groups.io <sailtamarack=
[email protected]>:

The intent of my post was to reply to comments by Victor Reijs and G3TXQ
(sk) that the S11 mode was not suitable for measuring high impedances.
When it comes to the NanoVNA this is not true and actual measurements like
the one I posted can be used to prove my point.

It is not me but

or

who derives the accuracy.
Can you provide where they go wrong? That would be very helpful. For me.
Thanks.

All the best,

Victor

Roger,
It now shows in Device Manager. The screen is still while but I can connect
with Nanovna Saver and calibrate using the Calibration Assistant. Do you
think it's usable when connected to the computer to analyze an antenna? I
may need to use it with NanoVNA App on my laptop. NanoVNA Saver won't
install on the laptop due to a Windows dll error.
Perry

On Tue, May 31, 2022 at 4:04 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Tue, May 31, 2022 at 06:44 AM, Perry Westberry wrote:

Tried this and still just a white screen. I guess it's bricked. Thanks

for all

the responses.
Perry

You posted that you cannot see it in Device Manager. Can you see it in
DFU mode? This will require opening it and shortening 2 pins.

Roger

The measure feature works well...from the user manual

1.2.5 MEASURE
3. CABLE S11
Choose a frequency range such that the cable length is ~1/4 of the wavelength in the middle of the range. This
feature uses velocity of propagation. It automatically measures the length, characteristic impedance, and loss at the
point of the active marker. Choose the range so that the Smith trace crosses near R=0 between 亇j. The shorter the
cable, the higher the frequency range needed for analysis. Example: Assuming the signal must go out and back on a
10 m length of coax, multiply c * VoP and divide by 4X the coax length. (3e8 m/s * 0.67) / 40m ~= 5 MHz. A range of
5乚15 MHz would cover this.

On Tue, May 31, 2022 at 01:26 PM, AG6CX wrote:

I wonder if you鈥檝e had the same experience with the VNWA as with the nanoVNA
in this regard? Do you find the S11 measurements are accurate (enough) for
higher impedances (presumably >50 ohms) ?

I do not own a VNWA so I have no first hand knowledge to share. From what I have read it has better specifications than a NanoVNA. You could join the VNWA group and pose your question there... /g/VNWA/topics

Roger

Hi Roger:

Thanks for your comments and focus on dispelling the notion that S11 with nanoVNA might be inappropriate for high(er) impedance measuring.

Re:

鈥淭he intent of my post was to reply to comments by Victor Reijs and G3TXQ (sk) that the S11 mode was not suitable for measuring high impedances. When it comes to the NanoVNA this is not true and actual measurements like the one I posted can be used to prove my point.鈥�

I wonder if you鈥檝e had the same experience with the VNWA as with the nanoVNA in this regard? Do you find the S11 measurements are accurate (enough) for higher impedances (presumably >50 ohms) ?

I appreciate your recent comments and look forward to more!

Ed McCann
AG6CX

Hello,
Being a past bata tester of FW for this unit, I have dealt with your problem.
The way I cured it is as follows:
First shut down the NanoVNA.
Remove the back cover.
Using small tweezers or what you ha e short the boot pad to the vcc pad next to it. While keeping the short, turn on the NanoVNA.
Remove the short, shut the NanoVNA off. Replace the back cover.
Now turn the unit on.
You should be able to re install the new, or old, FW by putting your NanoVNA in DFU mode via the menu,
I have had to do this several times so, I installed a micro switch to short the two pins without having to take the unit apart.
Clyde KC7BJE

Then turn the

To Roger:

Thanks for your comments.

Consistent with the physics involved.

Ed McCann
AG6CX

On Tue, May 31, 2022 at 06:44 AM, Perry Westberry wrote:

Tried this and still just a white screen. I guess it's bricked. Thanks for all
the responses.
Perry

You posted that you cannot see it in Device Manager. Can you see it in DFU mode? This will require opening it and shortening 2 pins.

Roger

Example:
Cable length measured in M1 point
Impedance on M2
More points in this range - better measure quality