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Sorry Larry?ThanksSent from my Bell Samsung device over Canada's largest network.

Doug,
PLEASE don't type your message into the SUBJECT area of the message - Use the message box below it!
If you're new to this, review the wiki and files sections and you can search the forum messages using search terms.
Also - if you're looking at getting a NanoVNA-V2 also known as SAA2, there are other websites and groups for that device - this forum is essentially for the original Nanovna, H and H4 models

Look here: /g/nanovna-users/message/21727

This group is mainly for the NanoVNA, NanoVNA-H and NanoVNA-H4. For info on the SAA2 with N connectors there is another group. You will have more luck with your question in that group. Please do not use all CAPS in your posts as it is considering shouting in these groups.

/g/NanoVNA-V2/topics

Roger

" Dave--How does it work standalone?"

Hi Todd,

I've moved forward a bit. I finally realised that some of the software
that I was trying to use was for updating the firmware and when I
downloaded a program called "NanoVNASharp" I was able to connect the laptop
to the unit and see the data on the screen.

After realising that the other software was fto upgrade the firmware I
moved on to doing that. I eventually stumbled across the information that,
on the firmware that I currently have, I need to hold down the rocker
switch and turn the unit on. With it plugged into the computer Windows
says that it has loaded the bootloader and I can see the unit details when
running DfuSe and I finally figured out which box I needed to specify the
upload files. As in, the one on the right and not the one on the left...

Cheers - Dave

--
David Ackrill

The slug looks fine when I removed it and examined it. The finish is intact and all the threads seem OK. The Capacitor is seperately mounted on the PC board right next to the RF transformer can. I rewound it and left the can off snd tried it figuring if it worked I would pout the can back and tweak the tuning after re inserting it. I don't get a peak at all. Its just flat. I am a bit mystified right now.

Has it been confirmed that the slug has not been fractured? Is the

sweep being done with the slug centred, the parts inside the can and the
can mounted on a p.c.b. plane?

John

at radio station VE7AOV.

+++++


On 2021-04-04 8:10 a.m., john_mellars via groups.io wrote:

I am not really sure about the failure. It happened when I pushed the PTT switch. The clue was that the output of the RF amplifier into the tuned circuit (primary of the transformer and the 5 pf capacitor is supposed to be about 1.4 V RMS. Replaced the transistor and now it about 20 mv drive at 136 MHZ on the base. The collector has about 200 mv pk. Moving the tuning slug causes no change at all. Removed the capacitor and transformer. Cap measured 3.8 pf this is so low not very sure. I tried to be careful with lead length etc. I also tried a new cap which measured 5.25 pf with the same result. Measured the inductor at about 0.1 uh. Calculation suggests it should be around 0.3 uh. The transistor collector voltage is fed thru the primary of the transformer but this all seems to be correct and the other bias points are right and the transistor seems to be working. Concluded the transformer primary must have shorted turns. I took it apart and rewound it and I measured it as going from about 0.270 to about 0.4 uh. Re-installed it all and I still get no peak in the resonance but still have the 200mv drive present at the top of the tank. It is still not resonanting so trying to figure out how to get the resonate frequency close before inserting it into the circuit again. I don't have a signal generator and therefore thought perhaps of using the NanoVNA as a way to get into the ballpark with it. I put 7 turns on the primary but the form is very small so difficult to determine if I have them distributed the same way (probably not) hence the idea of the NanoVNA to get a better view of it. The circuit is very straightforward so this seems to be the probable issue. It needs to resonant and the collector resistor is not in the tank circuit so would have expected a decent Q and a definitive peak as the slug is tuned.

--

I am not really sure about the failure. It happened when I pushed the PTT switch. The clue was that the output of the RF amplifier into the tuned circuit (primary of the transformer and the 5 pf capacitor is supposed to be about 1.4 V RMS. Replaced the transistor and now it about 20 mv drive at 136 MHZ on the base. The collector has about 200 mv pk. Moving the tuning slug causes no change at all. Removed the capacitor and transformer. Cap measured 3.8 pf this is so low not very sure. I tried to be careful with lead length etc. I also tried a new cap which measured 5.25 pf with the same result. Measured the inductor at about 0.1 uh. Calculation suggests it should be around 0.3 uh. The transistor collector voltage is fed thru the primary of the transformer but this all seems to be correct and the other bias points are right and the transistor seems to be working. Concluded the transformer primary must have shorted turns. I took it apart and rewound it and I measured it as going from about 0.270 to about 0.4 uh. Re-installed it all and I still get no peak in the resonance but still have the 200mv drive present at the top of the tank. It is still not resonanting so trying to figure out how to get the resonate frequency close before inserting it into the circuit again. I don't have a signal generator and therefore thought perhaps of using the NanoVNA as a way to get into the ballpark with it. I put 7 turns on the primary but the form is very small so difficult to determine if I have them distributed the same way (probably not) hence the idea of the NanoVNA to get a better view of it. The circuit is very straightforward so this seems to be the probable issue. It needs to resonant and the collector resistor is not in the tank circuit so would have expected a decent Q and a definitive peak as the slug is tuned.

John,

yes, you can use the NanoVNA for measuring the resonant frequency of your transformer with that capacitor, and for measuring the inductance. But you need to be aware that in VHF circuitry, using such low capacitance values, the stray capacitance of the circuit plays a big role. The resonant frequency of the transformer+capacitor installed in the circuit will probably be quite a bit lower than the one they have in free air.

How did it fail? Lightning, or transmitting into it, or what? Is it molten beyond recognition?

If at all possible, I would suggest to take it apart, count the turns, rewind it with the same number of turns in the same distribution, reassemble the circuit, and then tune the slug for proper response.

Manfred

Hello Jimmy!
FW from ojisancoubou works very good, but you can not become the screen capture in program NanoVNA-APP.
Vladimir

Hi there Vladimir! I was able to correct the issue with my NanoVNA-H white Gecko, I found out that the calibration set including the feedline cable was so horrible. The 50 Ohm load came with it is not a 50 Ohms load and is shorted as well. I tried the calibration SMA set that came with the NanoVNA-F by deepelec to the NanoVNA-H gecko and it works. The result value of my gecko is now the same as the NanoVNA-F.

NanoVNA-H V1.0.45 by Hugen79 White Gecko was updated to NanoVNA-D V1.0.53 by Dislord.
NanoVNA-F V0.2.1 by BH5HNU

There is nothing wrong with the NanoVNA from R&L it works great, built stout and the N-connectors are a nice addition.. Here is something that you won't find on that V2 group...



use that firmware from the japanese guy (google translate).

Works great on mine.

I have a VHF transceiver failure traced to a RF subminiature slug tuned RF transformer that failed. I took it out and am going to rewind it. I know from the schematic the parallel capacitor value (5 pf). I can calculate the requitred inductance since I know the frequency. Can I use the NanoVNA to check the rewound transformer and capacitor combination so I can be reasonably sure it resonates close to where it needs to be? I have no specs on the original transformer so I would like to find a way to get close. Any thoughts if I look at the circuits reflectantion coefficient and find the resonant frequency?

Dave--How does it work standalone? Try it on a crystal or something simple
like that. If it seems to work as expected, an error connecting via USB is
to be expected as well--that is, it would hardly be unusual. What software
(on the computer) are you trying to connect to it? --Todd K7TFC


------------------------------------------------------------------------------------
Todd F. Carney / Portland, Oregon, USA





On Sat, Apr 3, 2021 at 3:23 PM David Ackrill <david.ackrill@...>
wrote:

Hi,

I logged in a while ago and I didn't know if I'd bought a bad clone.

I now think I may have done. :-(

The unit came today in a well padded box, but the valuation in the
paperwork was very low, below what would attract import tax and VAT etc.
(I think this is trend in imported goods that I've seen. The people
sending stuff value it at a low price so that it does not attract customs
duty or get stopped before it is imported. I'm sure that the authorities
will get wise to this eventually and, even as I did not ask for this, it
will still be me that gets stung when the real value is found out...)

The cover of the box says "NanoVNA-H 4" and, in italics "Handheld Vector
Netcuork Analgger"

It came with o/c, c/c and 50 ohm standards plus two low loss cables and a
plectrum as well as USB lead and an Android phone cable (not a lot of use
to me as I have an iPhone...) As well as a through connector. The unit
powers up and seems to work OK, but I can't get my laptop to connect to
it. The system says it sees a new COM port, but I can't connect to the
unit. The error in Chrome says that it can't recognise the baudrate and
the software I downloaded from the Github won't instal.

If I've bought a pig-in-a-poke I'll put it all down to experience and will
give up on the miniVNA idea.


Cheers - Dave (G0DJA)

Please refer to the various user guides in the forum's files section, specifically the beginners guide.?
You're not seeing anything on your PC because you need the correct usb drivers installed for the device.?

Browse the forum wiki as well. This is not a device that you can turn on and use, like a voltmeter. You need to learn what a VNA is. There are a lot of YouTube videos. Again, the forum wiki and files sections have info and references for you.?
BTW, the odds are that you bought a good unit, you just need to start reading and learning about it.
Enjoy!

On Sat., 3 Apr. 2021 at 6:21 p.m., David Ackrill<david.ackrill@...> wrote: Hi,

I logged in a while ago and I didn't know if I'd bought a bad clone.

I now think I may have done. :-(

The unit came today in a well padded box, but the valuation in the paperwork was very low, below what would attract import tax and VAT etc.? (I think this is trend in imported goods that I've seen.? The people sending stuff value it at a low price so that it does not attract customs duty or get stopped before it is imported.? I'm sure that the authorities will get wise to this eventually and, even as I did not ask for this, it will still be me that gets stung when the real value is found out...)

The cover of the box says "NanoVNA-H 4" and, in italics "Handheld Vector Netcuork Analgger"

It came with o/c, c/c and 50 ohm standards plus two low loss cables and a plectrum as well as USB lead and an Android phone cable (not a lot of use to me as I have an iPhone...)? As well as a through connector.? The unit powers up and seems to work OK, but I can't get my laptop to connect to it.? The system says it sees a new COM port, but I can't connect to the unit.? The error in Chrome says that it can't recognise the baudrate and the software I downloaded from the Github won't instal.

If I've bought a pig-in-a-poke I'll put it all down to experience and will give up on the miniVNA idea.


Cheers - Dave (G0DJA)

Hi,

I logged in a while ago and I didn't know if I'd bought a bad clone.

I now think I may have done. :-(

The unit came today in a well padded box, but the valuation in the paperwork was very low, below what would attract import tax and VAT etc. (I think this is trend in imported goods that I've seen. The people sending stuff value it at a low price so that it does not attract customs duty or get stopped before it is imported. I'm sure that the authorities will get wise to this eventually and, even as I did not ask for this, it will still be me that gets stung when the real value is found out...)

The cover of the box says "NanoVNA-H 4" and, in italics "Handheld Vector Netcuork Analgger"

It came with o/c, c/c and 50 ohm standards plus two low loss cables and a plectrum as well as USB lead and an Android phone cable (not a lot of use to me as I have an iPhone...) As well as a through connector. The unit powers up and seems to work OK, but I can't get my laptop to connect to it. The system says it sees a new COM port, but I can't connect to the unit. The error in Chrome says that it can't recognise the baudrate and the software I downloaded from the Github won't instal.

If I've bought a pig-in-a-poke I'll put it all down to experience and will give up on the miniVNA idea.


Cheers - Dave (G0DJA)

I was able to convert the bin file to DFU.
You need an offset of 0x8000000 applied to the bin file prior to converting.
It's an interesting build BUT please remember - the author states there's bug, so be aware.
...Larry

The way you reset back to defaults is to connect the Nanovna to a serial terminal and run the

??????????????? clearconfig 1234

command

On Thu, Apr 1, 2021 at 11:35 AM, Larry Rothman wrote:

and a couple of other items

So is scale. reference position and electrical delay saved?

As I'm learning and tinkering with settings I'm not sure if there is an easy way to reset back to the defaults.

Sorry, correct download link:


I have tryed to convert BIN file to DFU file with DFuSeDemo - negativ.

Vladimir

Hello Sean!
Please reed here over the White NanoVNA remodeling and fw:

Please use Google Translate japanese---english
His FW is very different from edy555 and hugen.The last FW test version for NanoVNA is


Please note that this FW in the .BIN format, NOT .DFU. I loaded this FW into my NanoVNA-H using NanoVNA-APP 1.1.206. DFUseDemo can .DFU format only.

73 de Vladimir, dl7pga