Date   

Re: NanoVNA does not want to start -solved

tinhead
 

all caps replaced, inductor as well, i found even recommended parts, but still it does not work anymore. By closer look on the design, well, it works exactly as it should - it is power bank IC, it does power on with click on key, and power off with double click on key, while charging key is not working. So i added key button and happy with it.


Screen Protector

Mike Cohen
 

Just applied a screen protector to my NanoVNA.

Tech Armor HD Clear Plastic Film Screen Protector (NOT Glass) for New 2019
Apple iPhone 11 / iPhone Xr - Case-Friendly, Scratch Resistant, Haptic
Touch Accurate [4-Pack]

https://www.amazon.com/Tech-Armor-Protector-Case-Friendly-Resistant/dp/B07GZZXC78/ref=sr_1_14?keywords=tech+armor+screen+protector&qid=1568568369&s=gateway&sr=8-14

Note that this is a plastic screen protector that is easily cut to size
with a scissors. Most new screen protectors are ballistic glass that
cannot be (easily) cut without shattering.

Mike - AD4MC


Re: NanoVNA bricked

QRP RX
 
Edited

Adrian Waiblinger, if it shows that there is bad state in firmware, then it seems that memory is corrupted, so the only way to flash it is to use ST-LINK

Just use instruction above. If something will going wrong during flashing with ST-LINK, then use menu Target => Erase chip. It will clean all memory, so you will be able to flash it like new one with menu Target => Program and verify.


Re: nanoVNA Real Resistance Measurement Range

Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
 

On Sun, 15 Sep 2019 at 17:21, dl4raj <cpaul@gmx.net> wrote:

Ho George,

To my knowledge there are only a few amateur IV 1 port analyzers. The
EU1KY is one, a well as the AIM4170.

I cannot speak for the EU1KY but the AIM 4170 is definitely no IV analyzer.
Look at the circuit diagram on the W5BIG homepage.
(P.S. I own one myself.)
For more info on the IV method I've attached two HP/Agilent papers.
As you can see the HP impedance analyzers using this method start from
1MHz upwards
and they need quite sophisticated circuitry.

73
Clemens
DL4RAJ

I don’t see any attachments, but I am aware of the technique. I have an HP
4291B which uses the RF-IV method. Mine covers 1 MHz to 1.8 GHz, but later
instruments cover up to at least 3 GHz.





--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@kirkbymicrowave.co.uk
https://www.kirkbymicrowave.co.uk/
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


Re: nanoVNA Real Resistance Measurement Range

dl4raj
 

Obviously the attachments did not load up for some reason.
So I give it a new try...

73
Clemens
DL4RAJ


Re: nanoVNA Real Resistance Measurement Range

dl4raj
 

Ho George,

To my knowledge there are only a few amateur IV 1 port analyzers. The EU1KY is one, a well as the AIM4170.
I cannot speak for the EU1KY but the AIM 4170 is definitely no IV analyzer.
Look at the circuit diagram on the W5BIG homepage.
(P.S. I own one myself.)
For more info on the IV method I've attached two HP/Agilent papers.
As you can see the HP impedance analyzers using this method start from 1MHz upwards
and they need quite sophisticated circuitry.

73
Clemens
DL4RAJ


Re: New, disappointed member intro

Larry Rothman
 

John,
Have a look at what I did to my device:
https://groups.io/g/nanovna-users/files/Hardware%20Mods/NanoVNA%20Jog%20Switch%20Modification.pdf

To remove the rocker, start with the two tabs at the very edge of the PCB. The switch can then be lifted slightly to help unsoldering the 3 other tabs.

I was thinking that the button flex PCB could be found on older junk cellphones or tablets or cordless phone.

Larry


Re: NanoVNA bricked

Oristo
 

I am trying to jumper the boot to Vdd with a wire with alligator clip on each end.
So it's still booting normally with regular screen,
so wondering if there are any special tricks to getting the jumper connection,
or a better too like the connectors used for logic probing?
Overkill works for me:
http://ormpoa.altervista.org/nanoDFU.htm


Re: New, disappointed member intro

hwalker
 

John,
You'll have to search through the board, but a couple of posts have provided replacement sources for the multi-purpose switch. In the Wiki section there is a mod (https://groups.io/g/nanovna-users/files/Hardware%20Mods/NanoVNA%20Jog%20Switch%20Modification.pdf) for replacing the switch with a 3-button alternative like you suggested. I find the touch screen to be easier for navigating the device and really only use the switch for marker placement.


Re: New, disappointed member intro

John
 

Thanks for all the replies. I've connected the NanoVNA to my PC (Windows 7)
and it's working OK. I've even had a quick scan through the manual...

I don't have a can of compressed air. I could flush the switch out with a
jet of isopropanol and see what happens. I could replace the switch if I
had one, I have access to a reasonable rework station and a good
stereomicroscope, but I haven't found a source of that particular switch.
Actually I don't like the switch, not because it doesn't work but because
it sticks out and looks fragile. I'd rather have a row of three tiny push
buttons just accessible from the edge of the board. I'll have a look at the
circuit diagram. It should be easy enough.

If the supplier offers to ship another immediately and trust me to send the
faulty one back then I'll wait. If not I might just hang on to this one on
the basis that a VNA in the hand is worth two in the post.

I've tried the touch screen and it works OK.

John

On Sun, 15 Sep 2019 at 13:52, Larry Rothman <ac293@rogers.com> wrote:

Hi John,
Please remember that you can use this device via the touchscreen. However,
make sure to calibrate and save the touchscreen parameters. I created a
wiki entry on how to do that if your device has the default firmware.
73
Larry




Re: NanoVNA bricked

David J Taylor
 

From: Bruce KX4AZ

I am trying to jumper the boot to Vdd with a wire with alligator clip on each end. So it's still booting normally with regular screen, so wondering if there are any special tricks to getting the jumper connection, or a better too like the connectors used for logic probing?
=========================

Bruce,

I just bent 24 swg tinned copper wire into a "U" shape, tweaked the space so that it held itself into position to get the white-screen boot.

Cheers,
David GM8ARV
--
SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv


Re: List of NanoVNA Console Commands

Oristo
 

How does one enter console commands in a Windows 10 environment...use a terminal program to connect via a USB COMx connection?
PuTTY https://putty.org/
https://store.chipkin.com/articles/using-putty-for-serial-com-connections-hyperterminal-replacement/


Re: NanoVNA bricked

Bruce KX4AZ
 

I am trying to jumper the boot to Vdd with a wire with alligator clip on each end. So it's still booting normally with regular screen, so wondering if there are any special tricks to getting the jumper connection, or a better too like the connectors used for logic probing?


Re: List of NanoVNA Console Commands

Bruce KX4AZ
 

As a newcomer to much of this I have a simple question that gives away my inexperience...

How does one enter console commands in a Windows 10 environment...use a terminal program to connect via a USB COMx connection? I am assuming a command prompt window would not work. Or is entering console commands just a Linux only thing? Thanks in advance for "dumbing it down" for me.


Re: Using Linux CLI dfu-util question.

Andy 'FTD <punkbiscuit@...>
 

Thank you Rudi.
I've archived your post for future reference.
Many thanks.

73 de Andy


Re: List of NanoVNA Console Commands

 

Hello,

From the calibration and measurement results of full one-port measurements
of the reflection coefficient of a constructed experimental one-port black box,
we concluded by trial-and-error that, as it seems, the 1st line from below in p.1
of "NanoVNA Console Commands 8-6-19.pdf", that is this one:

"NOTE: need to determine what the output parameters above represent."

which is referenced to the Console Command "data", is redundant, at least in
this case, because, the values in the two 2 columns are - from left to right -
the Real part and the Imaginary part, respectively, of the reflection coefficient.

Sincerely,

yin&pez@arg


Re: New, disappointed member intro

Larry Rothman
 

Hi John,
Please remember that you can use this device via the touchscreen. However, make sure to calibrate and save the touchscreen parameters. I created a wiki entry on how to do that if your device has the default firmware.
73
Larry


Re: New, disappointed member intro

John Herleman
 

If you have access to a can of compressed air, it may be worthwhile to try blowing the switch out a bit and then carefully examine the rear portion where it contacts the silver metal backing. I found on mine that the metal had some sharp edges that impeded free movement. While I wouldn't generally recommend it, I have also put a tiny bit of lubricant on the back of the wheel and then used the compressed air to remove excess and to force some tiny bit of it into the mechanism. The switch is replaceable if you are comfortable with precision soldering but I suspect that you may be able to salvage it. I found only a single "spring" operated mine and, accordingly, it seems unlikely that it can be broken in one direction only. While well thought out, the open source nature of this unit often means that quality control is VERY compromised. Don't give up without a proper fight.


Re: NanoVNA bricked

Adrian Waiblinger
 

Hi

I tried what you said and it did not work. I get an error "Target 00 /error code: Bad state machine infirmware."

I have ordered an STL-Link 2 from your advice.

Thanks for your help

Regards
Adrian


Re: New, disappointed member intro

John
 

Hello Bruce,

Thank you for the reply. I can manually return the switch to the centre
position but the spring return no longer works except from the left
position. The movement of the switch feels "gritty".

I've had an answer from the seller who seems to think that a part was
missing, so I've replied to explain again that the switch is faulty. Yes, I
could use the NanoVNA with the PC software (although I haven't tried) but I
want to use it with a very compact Go Kit when I don't have use of a
computer. I'm expecting (hoping) for a replacement but I could learn to use
it in the meantime.

73,

John G4EDX

On Sun, 15 Sep 2019 at 11:56, Bruce KX4AZ <bruce@tustinfarm.com> wrote:

When you say it does not return by itself, does that mean you can still
manually "persuade" it to return by pulling it back from the stuck
position? If it is permanently stuck, have you tried using any PC software
to control the analyzer? That might at least let you collect data etc
while working on getting a replacement.



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