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NANOVNA-H GONE NUTS

 

My beautiful unit suddenly started to just start drawing lines all over the screen I hv recalibrated it several times.. Something is wrong as it was working fine. Question is there a reset ?? Is there a repair facility or is it just disposable ??
Thank You Paul Kobetz K2HZO Rubicon Observatory, Ukiah, Ca
 

Have you tried a Clearconfig 1234 from the USB Console using TeraTerm or the OneOfEleven NanoVNA app? It is discussed in the Wiki for this group. Once cleared do a Touch Cal, test Touch Cal and then Save. Go and do a full calibration and save to slot 0.

Roger
 

Roger TU for the reply I wish i understood what you are referring to? I went to the OneofEleven site and it is in GitHub I dont see an executable file which I could run. Darn, Your knowledge far exceeds mine.. Can you be more explicit? The Clearconfig 1234 same comment I am using Nanovnasharp.zip which becomes Nanovna.exe and is a great program It doesnt seem to hv a clear function ..
thank you Sir
Paul Kobetz
K2HZO
Rubicon Observatory
 

Paul,
Make sure you didn't turn OFF the calibration on the unit. In the calibration menu there is an Apply checkbox...make sure it's checked. However, with that said, sometimes it flips a bit and if you uncheck the box, calibration turns back on.?
Have a look.?


On Sun., 14 Feb. 2021 at 7:05 p.m., paul kobetz<pkobetz@...> wrote: My beautiful unit suddenly started to just start drawing lines all over the screen? I hv recalibrated it several times.. Something is wrong as it was working fine. Question is there a reset ?? Is there a repair facility or is it just disposable ??
Thank You Paul Kobetz K2HZO? Rubicon Observatory, Ukiah, Ca
 

Can you connect to the NanoVNA-H with the NanoVNA Sharp program? Do a calibration and remember to press Reset before you start and Done when you are finished. Save to a slot like 4. Then see if you can get the short, open and load on the left, middle and right of the Smith chart in the Sharp program. This will at least let you know if the NanoVNA can work in PC mode. If that works see if you can measure something in the sharp program.

The NanoVNA can be sent commands over the USB connection if you have a terminal program like Teraterm or Putty installed on your computer. This is called console mode. You just install TeraTerm which is free and then connect to the NanoVNA over the COM port. You can then send it commands like Clearconfig 1234. Search the Wiki for this group, previous messages and the files section of this group for further discussion of console mode.

Roger
 

The file you want is NanoVNA-App.rar. It is a rar archive, which is similar to a ZIP.

73

-Jim
NU0C


On Sun, 14 Feb 2021 16:49:46 -0800
"paul kobetz" <pkobetz@...> wrote:

Roger TU for the reply I wish i understood what you are referring to? I went to the OneofEleven site and it is in GitHub I dont see an executable file which I could run.
 

HI Roger
got it into terminal mode and ran Clearconfig but its not happy w the "1234" Then what ???
 

ok it accepted
config and all data cleared... yea So far so good..
73 Paul
 

This is what it does immediately after I save the cal data to 0 slot. Wow

IMG_0934.MOV
IMG_0934.MOV

 

Need check calibration kit/RF connectors/cable

If before calibration all look good, i think problem in 50 Om calibration, check it
 

load measured 50.1 on my VOM as soon as I say DONE it starts is there a repair facility anywhere? Silly thing, I really liked using it for antenna analysis. sigh..
 

You made calibration, and after you measure calibration load on this device and get 50 Om?

Or you measure calibration load on different device?
 

Measured on Fluke VOM..
 

Paul,

Don't throw in the towel yet.

Did you have the NanoVNA anywhere near a transmitter? I wouldn't put more than about 20 dBm into CH0 or CH1 or you can blow out the front end.

Have you tried connecting it to a PC program like NanoVNA Sharp to see if that works?

There have been problems like this reported before and sometimes it was faulty cal loads or a faulty cable. I know you tested the 50 ohm load but what about the short load? Do the cal right on the SMA connectors without a cable attached to eliminate one source of error. Try setting the frequency range to something low like 30 MHz. and see if that works.

Sometimes users forget to press Reset before doing a cal and Done when finished. I always hit Reset twice to make sure and then check the left of the screen to see that it is cleared.

As a last resort you could try reloading your firmware but only after all other avenues have been exhausted.

Hope you get it working again.

Roger
 

TU sir. Yes tried cal right at the terminal no cables. Checked the short and it is. The load is 50 ohms
I am too unsure of loading firmware but a Buddy ham offered Thought might hv been a static discharge as I was measuring the character of an antenna. So who knows. Perhaps he can un mess it up Hihi
Good excuse to buy the H4 from another Chinese company.
73 my friends
Paulk


Paul Kobetz
SKCC 19615C
CWOPS 2589
Rubicon Observatory

On Feb 15, 2021, at 5:06 PM, Roger Need via groups.io <sailtamarack@...> wrote:

?Paul,

Don't throw in the towel yet.

Did you have the NanoVNA anywhere near a transmitter? I wouldn't put more than about 20 dBm into CH0 or CH1 or you can blow out the front end.

Have you tried connecting it to a PC program like NanoVNA Sharp to see if that works?

There have been problems like this reported before and sometimes it was faulty cal loads or a faulty cable. I know you tested the 50 ohm load but what about the short load? Do the cal right on the SMA connectors without a cable attached to eliminate one source of error. Try setting the frequency range to something low like 30 MHz. and see if that works.

Sometimes users forget to press Reset before doing a cal and Done when finished. I always hit Reset twice to make sure and then check the left of the screen to see that it is cleared.

As a last resort you could try reloading your firmware but only after all other avenues have been exhausted.

Hope you get it working again.

Roger
 

a number of thread of similar problems on different units. So I don't think a dif mfg is going to solve the problem. One solution in a thread was to add ESD diodes which may be the best solution. Not sure what the best type are, but the ones specified were listed as "not for new design" and there were a couple opinions as to operating and clamping voltage. So if anyone has a good suggestion RE ESD diodes???
 

This has been discussed before:
/g/nanovna-users/message/2726
45 messages in thread.

On Tuesday, February 16, 2021, 10:52:15 a.m. EST, barnc4br@... <barnc4br@...> wrote:

a number of thread of similar problems on different units. So I don't think a dif mfg is going to solve the problem. One solution in a thread was to add ESD diodes which may be the best solution. Not sure what the best type are, but the ones specified were listed as "not for new design" and there were a couple opinions as to operating and clamping voltage. So if anyone has a good suggestion RE ESD diodes???

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