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I would strongly recommend buying from R&L Electronics. You won't get a
clone from them!! Here is the link to them for the NANOVNA-H4:




No connection to them other than having bought a number of NANOVNAs (too
many as they progressed) and TinySAs from them.

Dave - W?LEV

--
Dave - W?LEV

Nanovna-H4 is a great basic vna, if you don't need multiple GHz
frequencies. It runs the latest firmware and is actively supported. And
you should be able to get one for less than $100

Hi Jim.

Thanks for the reply. The answer is simple. Convenient! A pair of trees are there, about 100 feet apart and between them, nothing.
No balun used. The ends of the dipole are away from each tree by at least 20 feet. So its pretty much floating in space except close
to ground.

The ground is clay and can be damp at times. I cut the wire lengths wrong the first time and swr at 7050 was way off. Remeasured
and sure enough I was off by more than 10 feet! Cut a pair of 5 foot wires, twisted them in place, done. Hung the vna in the air with a
couple of gator clips, done. Coax back to the shack.

Although NEC says this is a zenith burner, there is still reasonable gain at say 45 degrees off horizon.

Have you checked the homepage(s). Like and
I can recommend V2 Plus4 Pro V2.4, it costs 299$ plus 18650 battery. But today I would try to buy pro version at 399.

There are several Group IO forum for VNAs. For instance /g/NanoVNAV2/topics

Hello Alan

Did you start with some ideal calculated length for 7.05 MHz, set the dipole at 7 feet high and then trim the length for best return loss? Or perhaps put up precut wire for a higher frequency and upon measuring found that 7.05 was the best match?

Do you have good soil conductivity? (Not dry, Rocky, Sandy soil?)

You are most likely operating NVIS but I’m curious as to how you arrived at that configuration.

Jim

I know this is old but thank you so much for posting that link about the larger screen job. That guy did an amazing job and it was enjoyable to scroll through Good day !

I am doing something wrong. I uploaded bin file of memory to my computer (NanoVNA.H.v1.1.00FromVanoVNA.bin). If I compare what I saved to my computer to memory, I get a match. I then downlodaed from dislord what I think is my firmware (NanoVNA.H.v1.1.00.dfu). I used dfuse_extract.py to convert to bin (NanoVNA.H.v1.1.00.bin). If I compare what I think is my FW (converted to bin) to memory, no match. The converted bin is 95KB. What I extract from memory is 1KB. I am not too concerned about the download (DFU) and converted (BIN) not matching. It may not be correct FW. What does concern me is the size mismatch. Something does not add up.

NanoVNA-H4

NanoVNA v2 Plus4

Istvaan

Hi Stan and others,
Thanks for the reply. Based upon my photos from earlier in the thread does a negative offset delay seem reasonable. It doesn't to me, but my experience is limited.
Best,
Chris

Hi,

I like to replace my first edition NanoVNA with a newer, read better one.

Can you advise me a good model that runs with the Nanovna-saver program and does not break the bank?

73' Ron
ON2RON

Normally you try to calibrate at the reference plane where you want to take the measurements, and the delay is set to 0.
The e-delay is a method of adjusting the position of the reference plane before making a measurement, and could be positive or negative - but the most common use is positive.
If you have an additional known length of cable/connector between your calibration point and the device you want to measure, you would enter a positive delay to represent that additional length.
If you calibrate and then remove a piece of cable, making the measurement plane closer than your calibration, then you can put in a negative delay to compensate for that length of cable that is not there anymore.
Note that e-delay does not do a perfect translation of the reference plane: it only compensates for time (i.e. phase and delay), not other impairments like loss in the cable. So calibration at the measurement point is preferred, especially for longer cables that could be lossy at the measurement frequencies.

Hello Robin.
Thanks for the response. The F-F adapter 15mm long. It was replaced with about 50mm of transmission line in the form of a female SMA with 50 ohm coax cable. My question is about using a negative value for the offset delay. +200ps looks terrible on the Smith chart, worse than no delay, whereas -205 creates a fairly tight cluster of points across the swept frequency. I'm fairly new to NanoVNAs and the NanoVNA Saver Windows app but all the articles and comments I read on Offset Delays are using positive values which to me imply compensating for a longer cable than what was calibrated. Is my head in vacuum?
Chris

Christopher,

in air—strictly vacuum—205 ps is equivalent to about 60 mm, which is not so far off the length of the F-F adapter that you had removed.

The numbers, when all is going well, tend not to lie.

HTH, 73,

Robin, G8DQX

On Mon, Aug 14, 2023 at 04:44 AM, Stefan Dimitrov wrote:

The situation is:
None on com ports menu and no any list.
The next menu:
"Disconnected"
Looks like no com ports or Windows 10 can't see the program.

You need to use Device manager to see if a COM port is active for your NanoVNA. If it isn't there you need to get it installed somehow. The method depends on which OS you are using.

Once you can select the correct COM port click the Disconnected button and you should be good to go...

Try reading the Absolute Beginners Guide in the files section of this group.

Roger

Hello,
I SOL calibrated my NanoVNA using a 30cm cable + F to F SMA coupler and the SOL end pieces. I removed the coupler and attached the 30cm cable to a ~5cm 50 ohm coax cable soldered to the input of a matching network which goes to a 900MHz Igneon PCB antenna. When using the tip of a knife to short the soldered-on end of the coax cable I need to use -205ps offset delay to bring the majority of the points to the left edge of the Smith Chart. Positive values make the plot worse. Is it ok to use a negative number with the NanoVNA Saver? That seems counter intuitive.

There are two Android apps for updating FW on the TinySA'S and NanoVNA H and H4's.
1- StmDfuUsb
2- StmDfuBlue for those who have installed bluetooth modual.
Both will install dfu, bin or hex files.
The apps will work on Android Cellphones or Android tablets.
The apps are available on the Play store and Google app store.
Clyde Lambert KC7BJE

I think I have finally gotten something installed to flash new FW on my NanoVNA-H. I installed STM32CubeProgrammer on MacOS Ventura. I tried, unsuccessfully, on Windows 11 under VMWare Fusion. In addition, I am running on a M1 macbook air.

See attached for my NanoVNA configuration and Download log. I am not in a hurry to update the FW, since what I have is doing the job. I have an overheating problem with this device which after about 30 mins the sweep charts go haywire. I have started the return process and have this device until the beginning of Sept. Good time to practice flashing FW. I have entered DFU mode on my NanoVNA and attached with USB cable. I connected with STM32CubeProgrammer and "device memory" shows a dump of data in the display. I am assuming this is the device memory. I clicked on the "Read" drop down and selected "Save as" and saved to my computer. I'm guessing I now have the bin file of what is currently on the device? If a flash goes back I could revert to this? I've loaded this file and compared with memory and get good result.

To flash, I would download the FW (bin) I wish to flash, click the download icon, browse to the downloaded bin, and click "Start Programming."

Anything wrong with my theory? Anything to add?

73,
Peter
WB3IZU

I had a 40 meter dipole at 7 feet above ground. Straight run no bends. At 7 feet, easy to clip the vna on and take a measure.
Better than 20 dB return loss at 7.050 MHz. At 10 W in, first contact was into VE3 land, 500 plus miles. NVIS?!?!

Losing 10 dB is HUGE for a closed 40m “loop” compared to a 40m dipole (doublet).

The trapezoidal loop was much lower 5m at one end 3m at the other compared to the doublet which is 10m away. The objective was to validate the existence of NVIS propagation on 40 m. A priori, at the zenith, the gain was good. It showed that none of the stations I was contacting on 40m were NVIS propagation. It would be necessary to do the same thing on 80 m but I don't have enough room for that.
73
--
F1AMM
Fran?ois

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

De la part de Barry K3EUI

Dear Roger,
The situation is:
None on com ports menu and no any list.
The next menu:
"Disconnected"
Looks like no com ports or Windows 10 can't see the program.
Best regards,
Stefan Dimitrov