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Re: #general_vna Saving to SD card
#general_vna
joe bell
My nano vna states SAA-2N,? HW version V2_2?? manufactured by Zeenko
if you need other information please state where to find it joe |
Re: #general_vna Saving to SD card
#general_vna
Just for understand - you mean NanoVNA-H or H4 ??
Not V2 model? My last post for NanoVNA-H or H4 |
Re: #general_vna Saving to SD card
#general_vna
I see CDC to USART adapter - this not NanoVNA port
NanoVNA port must have name STMicroelectronics Virtual COM PortDriver: |
Re: #general_vna Saving to SD card
#general_vna
joe bell
Hi DisLord, thanks for coming back to my shout for help
I installed the nanovna-save on win10 no problem, but I wanted to use an older laptop using win7 and that will not connect to the allocated USB port at all. Even typing the port number into the saver port box does not work. Running the QT version on the same machine connects every time! and also running the app by one-of-eleven connects every time. Anyone any ideas? Using Dell latitude laptop with Win 7 & SP1 I also loaded up the .net framework and VBS just to cross that off the list. I installed the Cypress driver from the? installer Plugging in the vna and checking com ports i get USBD Views After connection attempt has failed this message is added to ini file The .ini file has no file call? so I am left asking the forum for ideas my nano save is ver 0.2.2.1 Regards joe |
Re: Frequency accuracy
Remember, the difference between ¡°accuracy¡± and ¡°precision¡± is important.
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Accuracy has to do with the degree to which an instrument can determine a measured value compared to the actual value, independent of the method of measurement. Precision is the degree to which an instrument can display the actual value. For precision, think about measuring a length; does the scale read in 10ths of an inch, 100ths of an inch? And how accurate are those markings on the scale? DaveD On Dec 20, 2021, at 13:18, Earle Wilkinson <earle.wilkinson@...> wrote: |
Re: SWR measurement
On Mon, Dec 20, 2021 at 09:50 AM, Bo W4GHV wrote:
I suggest you read the Absolute Beginners Guide in the Files section of this group. Also check out the group Wiki. Roger |
Re: Transimission mesurements
Jens M?ller
Thanks Robin,
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vy 73 Jens Am 20.12.2021 um 12:56 schrieb G8DQX list: Jens, |
Re: Frequency accuracy
Earle Wilkinson
Thanks for the response will let you know the outcome
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Earle D Wilkinson (6Y5EW) Home page: Email address: earle.wilkinson@... Echolink: 6Y5RA On Mon, Dec 20, 2021, 10:21 AM Jim Lux <jim@...> wrote:
On 12/20/21 12:27 AM, Earle Wilkinson wrote:Earle D Wilkinsonminus |
Re: Transimission mesurements
Robin:
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Rather insensitive terminology here! "1) there is the odd Doll on this group as well as [far too many, /pro rata/] Guys¡± Chuck Young On Dec 20, 2021, at 6:56 AM, G8DQX list <list@...> wrote: |
Re: SWR measurement
The attached image indicates you are measuring from 50 to 52 MHz, not 1.9
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to 450 MHz. Dave - W?LEV On Mon, Dec 20, 2021 at 8:52 AM JF1XCV <hs@...> wrote:
Hi All! --
*Dave - W?LEV* *Just Let Darwin Work* |
Re: Frequency accuracy
Thanks, DiSlord for this! It's awfully close, and granted, for precision accuracy remember that we're comparing a $50-$75 device against oscilloscopes or spectrum analyzers which cost many times that....You get what you pay for, most of the time anyway. Tuning duplexer cans isn't for the faint of heart, but the NanoVNA will get you close enough to get into the ballpark.
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On Monday, December 20, 2021, 10:31:52 AM EST, DiSlord <dislordlive@...> wrote:
On Mon, Dec 20, 2021 at 07:21 AM, Jim Lux wrote: My fw allow made internal 26MHz TCXO correction (see CONFIG->EXPERT SETTING->TCXO) Power on device, set 26MHz CW output Wait near 5-10min for device warm Measure output frequency Enter this value as TCXO Save confog. Now as minimum up to 100MHz Nano have only +-2Hz error. (Error bigger on more high frequency) |
Re: Frequency accuracy
On Mon, Dec 20, 2021 at 07:21 AM, Jim Lux wrote:
My fw allow made internal 26MHz TCXO correction (see CONFIG->EXPERT SETTING->TCXO) Power on device, set 26MHz CW output Wait near 5-10min for device warm Measure output frequency Enter this value as TCXO Save confog. Now as minimum up to 100MHz Nano have only +-2Hz error. (Error bigger on more high frequency) |
Re: Frequency accuracy
On 12/20/21 12:27 AM, Earle Wilkinson wrote:
Earle D WilkinsonTwo issues that arise: #1 The NanoVNA only has a limited number of frequency steps (101,201,401, depending on which firmware and model) unless you're using software on an external computer that does multiple scans. So, if you set your span to, say, 147 to 148 MHz, then you'll get a measurement every 10 kHz (with 101 points).? Solution here is to use one of the many software packages that will talk to the NanoVNA and make multiple scans and combine them. #2 The 28 MHz oscillator in the NanoVNA isn't necessarily accurate enough.? I don't recall the spec, but let's say it's on the order of 10 ppm (good for a TCXO) - at 147 MHz, that means it could be off by 1470 Hz. |
Re: #general_vna Saving to SD card
#general_vna
Kingston 8Gb HC Card.As i see log, no any card installed: 38.945 rx: SD_WaitNotBusy CMD0 err, 00This string mean Nano Ask for card, and no any answer - Check the correctness of installation in the slot, the card should be contacts to the board and completely recessed into the connector (outside should be 1-2mm) - Card not answer - need check card contacts to MCU (see H4 schemantic) and power (sould be 3.3V) - I hope you have original H4 (some clones have diffirent LCD molule, this module not allow read from card) |
Re: SWR measurement
On 12/18/21 8:19 AM, JF1XCV wrote:
Hi All! You have a transformer with 36:1 impedance ratio, and an 1800 ohm load.? You should see 50 ohms on the other side. That is pretty close to what you see.? What were you expecting? |
Re: #general_vna Saving to SD card
#general_vna
Good afternoon.
The same problem with saving to the card. Kingston 8Gb HC Card. |
Re: Transimission mesurements
Jens,
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1) there is the odd Doll on this group as well as [far too many, /pro rata/] Guys 2) for the technical question, imagine that there are *2* oscillators active, one at f?, one at f?+IF, where IF is an intermediate frequency and f? is the measurement frequency. Then, as square waves, the measurement oscillator will produce frequencies f?, 3f?¡, and the local oscillator will produce frequencies f?+IF, 3f?+3IF¡ Then at the fundamental frequency, the difference frequency is IF, but when the third harmonic products mix, the difference frequency is 3IF. The products at 3IF will be rejected by the post mixer bandpass filter. 3) similar arguments apply when harmonic mixing is employed, such as for the 300?MHz - 900?MHz range. Note in this case, that there will be an unwanted product from the fundamental frequencies at ?IF (hence the use of a bandpass, rather than lowpass, filter) and the 5^th harmonic at 1?IF. Also note the reducing power in the harmonics, thus doubly reducing the mixer products to be measured. The fact that any of this works is a triumph of human ingenuity and DSP. 4) Identifying all the frequencies and corresponding mixing products for n^th harmonic operation is left as an exercise for the interested reader! HTH, 73, Stay Safe, Robin, G8DQX PS: For this sort of hybrid analogue & digital machine, often the block diagram is more informative than the circuit (schematic) diagram. The actions of the software are also key components. On 20/12/2021 11:11, Jens M?ller wrote:
Hello Guys, |
Transimission mesurements
Jens M?ller
Hello Guys,
I've one question which puzzles me, and was unable to find information neihter in the forum nor in the Wiki. Since the NanoVNA outputs a rectagular signal which's harmonics are not neglectable and has no selective input (what I can see from the schematic is broadband), how can the S12 and S21 measurements be accurate as all the harmonics of the output will go into the mesurement at the input. What do I have overseen? Thanks for bringing me on the right track Jens DF9HJ |
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