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On 8/15/22 12:31 PM, Nick wrote:

Dear all,
Newby here,
I have a NanoVNA-H rev. 3.3.
I flashed the latest firmware 1.2.00 from DisLord.
After opening the unit, I found out that there are no shields around the inputs. Little smd standposts are installed for shields.
I could make shields with Kapton and copper tape.

Even better, you could buy actual shielding cans, typically made of nickel plated steel. They're cheap, and do a better job shielding (skin effect is shallower, so they're lossier)

Will making shields improve the unit?
Are there other mods that I should consider?

Does it work for you now? I wouldn't modify unless there's something that doesn't work. You could wind up spending more in time and money making mods that might be better spent just getting a newer, better unit.

Update to my SV4401A review - The tech guy said they are working to debug the nanovna-saver app. There seems to be a common script execution problem in Python programming. As for the power on issue, we are discussing possible battery issues. I will replace mine (I can always use a spare set of batteries). I am having better success with the power on problem by discharging the batteries somewhat. It seems that fully charged batteries may have a bit too much energy at power on that may be glitching the startup circuit. I wish I had the schematic, which I will ask for. More updates on that later. If I get home from work tonight and I am able to turn it on, then I'm getting somewhere. Stay tuned.

This instrument offers so much more than the original or the F model and I believe was mainly designed for lab use. Yes, it's only an F model in a big box with big screen and big connectors, but also more memory, more resolution and it even calculates matching networks for the measured impedance. I'll keep mine regardless of the outcome of the power up problem, and the software I'm sure will be fixed.

Hi Doug, Are you able to get on Zoom? I would be glad to get on Zoom with you and walk you through the menu steps to make sure you are not doing something wrong.

Send me an e-mail if interested and we can schedule something. My e-mail wa1jxr@...

73 Greg WA1JXR

Dear all,

Newby here,

I have a NanoVNA-H rev. 3.3.
I flashed the latest firmware 1.2.00 from DisLord.
After opening the unit, I found out that there are no shields around the inputs. Little smd standposts are installed for shields.
I could make shields with Kapton and copper tape.
Will making shields improve the unit?

Are there other mods that I should consider?

Thanks for your replies

I am using this new NanoVNA-H with Nano Controller software from Github. After calibrating for 80 meters and then sweeping from 3.5 to 4.0 with step 0.01, the results show 4.95 all the way across. I repeated the process for my 20 meter half wave dipole which has SWRs below 1.5 all across, but the sweep showed 4.95 all the way across. Clearly this is not working, any suggestions?

Doug
VA3PSI

Radio astronomers have been receiving (they call it "observing") on submillimetric wavelengths for many years. That's frequencies above 300GHz.

There has been a surge of interest in the 122GHz and 134GHz ham bands, and there are hams here building gear for that (mainly transverters). Of course, 47GHz, 76GHz bands are in full swing. And lest we forget, there is also 241GHz and 275GHz ham bands that some enjoy.

Stephen W9SK

When doing the 30-40 GHz calibrations we were characterizing 20 GHz serial links for both in-package and pcb traces for Xilinx serdes devices (mainly NRZ signaling). We calibrated to multiples of the link operating frequency to properly characterize the link at multiples of the harmonic frequencies of the signaling frequency.

That was about 2 years ago when I retired. Now the serdes transceivers are deal with 120 GBit data (doing it using PAM) so the test equipment requirements have increased, but not as much as it might seem at first glance.

Ray WB6TPU

On 8/15/22 8:47 AM, Chris K2STP wrote:

On Fri, Feb 19, 2021 at 02:50 PM, Ray Anderson wrote:

Wow, can I ask what the heck one does looking at 30 and 40 GHz? (to a layman’s perspective please, I’m not sure what language you smart folks speak in most of the time! ;-) )

Deep Space Telecom uses 32 GHz (Downlink) and 34 GHz (Uplink).
There are radars a bit higher.

There's an allocation for 5G at 39 GHz (37-40)

Plenty of activity for short point to point wideband links.

And, then, there's always "mmWave as an IF or LO for a THz system"



There's oscillators at 36-38 GHz that get multiplied up (x2,x3,x3 for Tx)

On Mon, Aug 15, 2022 at 06:13 AM, Jim Lux wrote:

After all Keysight/Agilent/HP are all closed source units, and quite
popular; warts and all.

Yes Keysight/Agilent/HP they are closed source but have service depots/manuals, technical support, warranty and software updates to fix bugs and add new features.

Most small Asian manufacturers have none of the above and users provide support to each other in forums like this. Third parties do the software development if the product is open sourced. If the product is closed source like the -F the user is lucky if they get a periodic bug fix or new features and if the hardware has a problem/failure you are out of luck.

Roger

On Fri, Feb 19, 2021 at 02:50 PM, Ray Anderson wrote:

For doing cals up to about 1Ghz for a nanoVNA it probably isn’t that big of
a deal, but just thought I’d mention it. (I’m used to doing vna cals up to
30 or 40 GHz where it is a big deal)

Ray WB6TPU

Wow, can I ask what the heck one does looking at 30 and 40 GHz? (to a layman’s perspective please, I’m not sure what language you smart folks speak in most of the time! ;-) )

--
Regards,
Chris
K2STP

Well, he was right! It is now pdf / white paper worthy on the subject of, “How to comment on how good a thread is”. ;-)))

--
Regards,
Chris K2STP

On 8/15/22 2:18 AM, David J Taylor via groups.io wrote:

On 15/08/2022 09:22, F1AMM wrote:

Concerning the nanoVNA-F which works very well alone and connected with nanaovna-saver under Win7, here is what Roger Need answered me

/g/nanovna-users/message/29253

The NanoVNA-F is not an open source design. The manufacturer does not publish schematics or source code for this product.

I don't know if it can be important in the context of my OM use.--
Fran?ois

Fran?ois,
Being "open source" can allow others to provide updates which enhance the
functionality of the hardware, and perhaps fix bugs left by the manufacturer.
On the other hand, there seem to be many different firmware versions, leading
to confusion among the users, and incompatibility with the Windows support
programs.
Open source can lead to: "Something only works with version X.X of the
firmware, and Y.Y of the NanoVNA Saver.? Oh, but I have version Z.Z of the
firmware, so how do I upgrade?? Oh, that's too complicated for me!"
For me, open source is a "nice-to-have" feature. but it would not stop a
purchase, assuming that a unit got generally good reviews.
73,
David GM8ARV

After all Keysight/Agilent/HP are all closed source units, and quite popular; warts and all.

Hello!

I still use a twelve-centimeter slide rule (or a circular one) in my everyday life.
Most often when I need to decide which goods is cheaper in a grossery shop - by bringing the compared goods to the common measure (be it weight or price).

Warm regards,
Tony

On 15/08/2022 09:22, F1AMM wrote:

Concerning the nanoVNA-F which works very well alone and connected with nanaovna-saver under Win7, here is what Roger Need answered me

/g/nanovna-users/message/29253

The NanoVNA-F is not an open source design. The manufacturer does not publish schematics or source code for this product.

I don't know if it can be important in the context of my OM use.--
Fran?ois

Fran?ois,

Being "open source" can allow others to provide updates which enhance the
functionality of the hardware, and perhaps fix bugs left by the manufacturer.
On the other hand, there seem to be many different firmware versions, leading
to confusion among the users, and incompatibility with the Windows support
programs.

Open source can lead to: "Something only works with version X.X of the
firmware, and Y.Y of the NanoVNA Saver. Oh, but I have version Z.Z of the
firmware, so how do I upgrade? Oh, that's too complicated for me!"

For me, open source is a "nice-to-have" feature. but it would not stop a
purchase, assuming that a unit got generally good reviews.

73,
David GM8ARV
--
SatSignal Software - Quality software for you
Web:
Email: david-taylor@...
Twitter: @gm8arv

The NanoVNA-F, LiteVNA 64 or NanoVNA V2 plus 4 are what I would recommend.
David

Concerning the nanoVNA-F which works very well alone and connected with nanaovna-saver under Win7, here is what Roger Need answered me

/g/nanovna-users/message/29253

The NanoVNA-F is not an open source design. The manufacturer does not publish schematics or source code for this product.

I don't know if it can be important in the context of my OM use.--
Fran?ois

-----Message d'origine-----

De la part de David J Taylor
lundi 15 ao?t 2022 09:59

On 14/08/2022 21:24, Ken Bozarth wrote:

I recently purchased an SV4401A from Aliexpress for $299. As a lab instrument, it is very nice, a giant step up from the F-V2. With up to 1001 data points, the sweep resolution is great. The N connectors are nice too, though a cal set of N types would have topped it off. It has mass and is ruggedly built, inside and out. The batteries are replaceable without soldering.

My unit has two serious issues, which I am trying to work through with the tech guy at Sysjojnt, who also developed the V2. The software nanovna-saver is picky about which Win10 pcs it'll run on. I get a failed to execute script msg. Strangely it runs on my cheap tablet and a desktop at work. Three others will not work. I am not a pc or Windows expert. Maybe there is a setting that will let it run? The other issue I have is that, when left off for a while unplugged, it will not boot. Instead, it cycles through a power on sequence indefinitely. The batteries are fully charged. So to take it outside I must bring a 5VDC power source with type C USB connector. Whether these problems are design flaws or just with my unit remains to be seen.

I wasn't happy with mine and sent it back for a refund.

It only worked with the charger connected, the firmware seemed very limited
compared to current models, and it wouldn't keep the date and time.

It's actually an SMA unit inside, so the N connectors just add expense, and
make the unit very heavy (including batteries). They even provide an SMA
calibration set with adapters. I would liked to have kept the unit (that's why
I bought it, and an N calibration set for another $125), but I feel it's not
yet ready for prime time.

The NanoVNA-F, LiteVNA 64 or NanoVNA V2 plus 4 are what I would recommend.

Cheers,
David
--
SatSignal Software - Quality software for you
Web:
Email: david-taylor@...
Twitter: @gm8arv

For a parallel resonant circuit there are three different definition of resonance (Nelson
M. Cooke, "Mathematics for Electricians and Radiomen," McGraw-Hill, 1942, page 478):

1. The frequency at which the parallel circuit acts as a pure resistance;

2. The frequency at which the line current becomes minimum;

3. The frequency at which the inductive reactance equals the capacitive reactance.

For a high-Q circuit, the differences may be negligible, but for a low-Q circuit, they
may be of sufficient value to be important.

For a series circuit all three values are coincident in frequency.

73,

Maynard
W6PAP

Sorry for the late reply but I've been away.

There is only one definition of resonance - that where the reactive component of the impedance is zero. That is true for ANY AC circuit - including antennas.

But you're correct in that it might not matter much. While a 3:1 SWR will cause transmitters to cut back, it's only a 25% power loss or about 1.25db. When you consider 1 S-Unit is 6db (ideally), that's about the width of the needle on many S-meters. Nothing noticeable except in the most extreme conditions.

No, a 1:1 SWR may not occur and won't in most antennas. But don't count on the lowest SWR being at resonance - in fact, very few antennas will have a 50 ohm impedance at resonance without some type of matching network.

I recently purchased an SV4401A from Aliexpress for $299. As a lab instrument, it is very nice, a giant step up from the F-V2. With up to 1001 data points, the sweep resolution is great. The N connectors are nice too, though a cal set of N types would have topped it off. It has mass and is ruggedly built, inside and out. The batteries are replaceable without soldering.

My unit has two serious issues, which I am trying to work through with the tech guy at Sysjojnt, who also developed the V2. The software nanovna-saver is picky about which Win10 pcs it'll run on. I get a failed to execute script msg. Strangely it runs on my cheap tablet and a desktop at work. Three others will not work. I am not a pc or Windows expert. Maybe there is a setting that will let it run? The other issue I have is that, when left off for a while unplugged, it will not boot. Instead, it cycles through a power on sequence indefinitely. The batteries are fully charged. So to take it outside I must bring a 5VDC power source with type C USB connector. Whether these problems are design flaws or just with my unit remains to be seen.