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Re: NanoVNA firmvare, compiled by DiSlord #firmware with MiniSD support
#firmware
Great, thanks!
I'll give it a try. Sent from Rogers Yahoo Mail on Android On Sat, 6 Jun 2020 at 10:54 am, DiSlord<dislordlive@...> wrote: On Mon, May 25, 2020 at 12:56 PM, Larry Rothman wrote: I compile NanoVNA - H firmware vs SD Card support, not tested, i hope it work If you have installed SD card slot on NanoVNA it you can try check work Work as on h4 version vs some limits (not supported exFat filesystem, and not use long filenames, limits from less flash size) Enable console and made some screenshots and try save s1p or s2p file |
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3 outputs splitter (MX-3000D) use.
As i'm using the NanoVNA-H essentially for HAM bands, i tried to use a 3 outputs splitter (1.6 - 160MHz, 350 - 500MHz and 850 - 1300MHz).
I've done one 2 ports calibration for each output. The measured spectrum for each output is not too bad (far better compared to direct VNA output) and SWR measurements on HF, 6m, 2m , 70cm and 23cm seem to be corrects. I tried to use a little Tera Term macro for direct frequency setting and that's ok too. (By choosing the correct splitter's output!) 73 QRO, Rudi, HB9ARI |
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Re: NanoVNA firmvare, compiled by DiSlord #firmware with MiniSD support
#firmware
On Mon, May 25, 2020 at 12:56 PM, Larry Rothman wrote:
I compile NanoVNA - H firmware vs SD Card support, not tested, i hope it work If you have installed SD card slot on NanoVNA it you can try check work Work as on h4 version vs some limits (not supported exFat filesystem, and not use long filenames, limits from less flash size) Enable console and made some screenshots and try save s1p or s2p file |
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Re: Test do not read
I wrote the test message.
I had made my first post, but I could not see it. I made the second test post to see if that would go through. When I posted the test post, I saw the note that it would be moderated. Then I knew that's why I had not seen my first post it had not went through the moderator yet. I got both posts in my email at the same time. Tell me how to remove it, and I will. Or you can continue to read it and say you didn't ;-) Mikek |
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Re: Definition of terms
Hi,
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A newcomer facing the base of a steep hill probably doesn't know what words to use when asking a question. First would be "how do I turn this thing on?" They probably can look that up for themselves but other questions may not be so easy. I am new to the nanoVNA but came to it with some foggy ideas about what it does and even how. But as with other new ventures, I read the wiki and the how-to and find new words or even old words in a new context. With Google and other search engines we can then look up those new words. that constitutes 'climbing the hill'. I am a radio amateur. I had to learn CW. No..it's not weeping about dropping that requirement. I helped some others working for their license. The ones who actually took the time to learn the Morse code succeeded. I could not *learn* it for them. All we can really do is point to the start of the trail that leads up the hill and the newbie is then welcome to climb as far as they want to go. There may come a fork in the trail and a new pointer can be offered. The people who *know* cannot know for you (newbie). There is a reference to "hands-on" in the thread. I have found that a balanced mix of 'book learning" and hands-on is needed. Newbies should not feel 'dissed' by 'rtfm' if given the page and paragraph number to read. 73, Bill KU8H bark less - wag more On 6/6/20 7:07 AM, gary.sewell@... wrote:
First I want to thank all that responded to to my question. I remember back in my college days in the late 60¡¯s, we used very large Tektronix scopes, and on the top of the scope was a small pop-up compartment that held a small manual. On that manual it stated ¡°RTFM¡±. For those that don¡¯t know what this acronym means, it is ¡°Read The Fu#king Manual¡±. I remember how thick that actual manual was, and it may take hours of searching the manual to find out how to use a function on that scope. So instead we would ask the instructor and they would give you the answer. |
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Re: New user, dove in above my head.
First, I think that you are shorting one side of your balanced input to ground.<Yes, at the very least, to the shield potential of the radio, connecting an earth ground to the radio makes no difference to the common mode signal attenuation. I did not realize the grounding. Yes. measuring the input with a 50 ohm resistor on the output gave me about 92 ohms at 500kHz rising to 109 ohms at 4MHz.. Ah, I will add a 4 to 6 turn transformer at the input and measure again, and I'll wind the second just to measure the loss of the two transformers, divide by two to find the loss of one. Good, I will measure the common mode impedance with that method. Thanks, Mikek |
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Re: Definition of terms
First I want to thank all that responded to to my question. I remember back in my college days in the late 60¡¯s, we used very large Tektronix scopes, and on the top of the scope was a small pop-up compartment that held a small manual. On that manual it stated ¡°RTFM¡±. For those that don¡¯t know what this acronym means, it is ¡°Read The Fu#king Manual¡±. I remember how thick that actual manual was, and it may take hours of searching the manual to find out how to use a function on that scope. So instead we would ask the instructor and they would give you the answer.
Fast forward to today with Google, YouTube, Wiki, etc. These tools make life so much easier. But, the problem is sometimes even with these great tools, you still cannot find the answer you are looking for. After many hours of searching, you have two choices: give up and move on, or ask for help. I choose the later. The NanoVNA is a great tool, and I wish I had something like this many years ago. But, like that old Tek scope, it has features and functions, that to some, are new and hard to understand. I come from ham radio where SWR was all you had to found out how an antenna performed. Now, I am an engineer with many years in RF communications, but a lot of the brain cells have reformatted and now need to be updated. I would hate to think that this great tool we have could be construed to be so complex and hard to understand and use, that it too ends up on the unused shelf in our shack collecting dust. Thanks again Gary AA5I |
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Re: Definition of terms
One huge problem with looking up info on the wiki or elsewhere is that
of generating the correct search term. Once in a while one hits on it quickly, but more often one wastes hours in a futile effort, and in the process is bombarded with an almost infinite number of things to look through. Another problem is that much material is written so poorly that it fails to answer the real question satisfactorily and without ambiguities. I submit that in this day and age one should not have to invest hours looking for information- it should be easy to find. Hence, my own inclination is to ask people (as opposed to algorithms) for help. Dana |
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Re: New user, dove in above my head.
First, I think that you are shorting one side of your balanced input to ground. Starting at "Transformer center taps connected to case", then through the case to the BNC shell, then to the ground on the VNA, then to the shell of CH0, then to one of the balanced input lines. So I don't think that any of your measurements mean anything.
If you want to measure the balanced input impedance, you could connect a floating 50 ohm load at the output BNC. You should expect to read 112.5 ohms, this is the impedance because the 6 to 4 turn ratio results in the turns ratio (1.5) squared (2.25) times 50 ohms. To measure the through loss, you could make another 4 to 6 turn transformer and connect it between the CH0 and the balanced input. Any loss you measure needs to be divided between this balancing transformer and the device under test. You could connect two identical 4 to 6 turn transformers back to back, measure the loss and divide by two, then just subtract this test fixture loss from the overall loss you measure. You might also want to evaluate the common mode impedance by connecting the CH0 center connector to the shorted together balanced input lines and connect the BNC to CH1, to provide both a ground return and a load on the output. |
John
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