Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- Nanovna-Users
- Messages
Search
Re: About cable delay compensation and NanoVna_Saver
#improvement
#test-jig
#tdr
#nanovna-saver
#measurement
On Sun, Jan 12, 2020 at 10:39 AM, hwalker wrote:
Try the version Rune released yesterday. That bug had been reported beforeHerb, Thanks for the correction to my previous post. You were right! The latest version has fixed the bug. I just made a number of tests using NanoVNA saver 2.2 with different length cables and got good results by just entering an estimate for one way delay and then varying for best results while watching the Smith Chart and S11 phase delay. . I also compared using the offset delay in the program and the equivalent electrical delay parameter in the NanoVNA hardware and got agreement there as well. The electrical delay used in the hardware parameter is the round trip delay so I divided by 2 to get the offset delay in the Saver program. Roger |
Re: android app?
On Sun, Jan 12, 2020 at 11:58 AM, Pete Buxton wrote:
" ...I was excited when I found that it connected on serial port using PuTTY, but can't find any info (other than the help command) how to control it with commands. I suppose using Linux with Python scripts that I've seen mention of would be similar, better way to do it .." ============================================================= Pete, Python runs on all platforms except for Android, so if you like to rolling your own solutions then it is a great way of controlling the NanoVNA with your own scripts. On the other hand, If you prefer ready made solutions, then you can't go wrong with Rune's NanoVNA-saver application or any of the NanoVNA-Sharp variations. One of the things I really appreciate about Rune's NanoVNA-saver is that it is written in Python and Rune makes the source code publicly available. If you are learning Python, his code is an invaluable resource of real world example code. Back to Texans versus Chiefs. Still trying to figure out what happened to Baltimore last night. - Herb |
Re: Calibration help - above my pay grade.....
Not only can our ears not detect much below 30 Hz, our radios don't do too
well with that frequency and below, either. Most cut off 'around' 100 Hz. For those who must split hairs on frequency accuracy, WWV suffers variations depending on propagation and short-term variations (Doppler) due to an unstable ionosphere, even in these days of minimal solar activity. I'm fortunate in that I receive WWV at 2.5, 5.0, 10.0, 15.0, 20.0 and 25.0 MHz 'mostly' via groundwave (near Berthoud, Colorado). WWVB is on 60 kHz and on long paths (like the east and west coasts), does not suffer the Doppler variability that the HF signals do. If you want the ultimate without ionospheric modulation, procure a GPSDO and use that as your frequency standard. Mine typically runs in the couple of parts in 10 E 11 on the 10 MHz output. Occasionally, the display indicates a bit better (and worse), but is far better than ionospherically propagated HF WWV. I believe AirSpy is now selling the Bondar GPSDO (no connection). Another excellent application for this purpose is Spectrum Lab, < >, as opposed to FIDIGI. Softpedia also offers it. It's freeware and has become pretty much the standard for the VLF and ELF'ers. I use it extensively for meteor scatter from distant DTV signals. Dave - W?LEV On Sun, Jan 12, 2020 at 7:15 PM Lawrence Macionski via Groups.Io <am_fm_radio@...> wrote: David GM8ARV--- *Dave - W?LEV* *Just Let Darwin Work* *Just Think* |
Re: android app?
Thank you, Herb,
With your advice, I will try the nanovna-saver on Windows but thought I'd try the Web app just for kicks. I wasn't aware of the Web app until I saw your mention of it in this post. Searching after that, it seemed the posts that I missed talk about it in the context of Chromebook, which I don't have. Before that, I sideloaded Google Play Store onto my 2015 Amazon Fire 7" tablet (which is Android ver 5.3), so of course, the Android 7.0+ app wouldn't install. I wish the author could make it more backward compatible. I had hoped my $50 tablet would work with the equally cheap $50 NanoVNA. :>) I've only had my NanoVNA a few days and am just getting started. I was excited when I found that it connected on serial port using PuTTY, but can't find any info (other than the help command) how to control it with commands. I suppose using Linux with Python scripts that I've seen mention of would be similar, better way to do it. -Pete |
Re: Si5351A Part Number
#repair
#internals
I am not a fan of the Si5351. It was intended to be used for digital clock generation for processors and peripherals, not for RF signal generation where reasonable signal quality is needed. Its only attribute is it is cheap, and can do low frequency.
It is the weakest piece of the nanoVNA design. It has a lot of close in spurious outputs, terrible jitter and therefore terrible sideband noise. It is the dominate item limiting dynamic range. The spec is almost useless and applications notes are difficult to read and understand. The app note AN614 Document change list is laughable with the amount of major errors caught in the document. Other then that it is a great chip. A technological leap above the transmitter on the Titanic ; |
Re: Calibration help - above my pay grade.....
David GM8ARV-
Yes, the ADAFRUIT white page on their SI5351 board I linked to does elude to setting the frequency to 1ppm. I have found and knew it for years, "ZERO BEATING" to WWV doesn't work, because humans can't hear lower than 20-30 cycles depending on age and history with cannon fire. For those who are not hams FLDIGI is a program for decoding various ham radio digital modes. It uses a computer sound card to display frequency versus time versus intensity (amplitude) in a waterfall display. It has audio frequency readout. Now before someone pipes up - "Well how do you know that's accurate?" We don't .. but what we do know is that WWV and it's carrier is accurate, by superimposing our NanoVNA CW mode signal at 10.0000 or injecting it into the same receiver using nearby antennas.. we can see the WWV carrier and the NanoVNA carrier and see the frequency difference on the waterfall display. In my case it's 110 cycles. WWV is also at 5.0000, 15.0000, 20,0000 and there is also CHU Canada available. So, these days we don't need a capacitor to change, or slug tuning.. Even the SI5351 data sheet specified a crystal in the 25-29 mhz region.. That's because somewhere we deposit a number in a register that aligns the accuracy of the output of the SI5351.. granted to enviromental tolerances, but for a $50 "gizmo" that is in use world wide, that's fantastic.. I started with a US Army Signal Corps BC-221-AF frequency meter, which was the "best you could get" when I got my 1st class Commercial Radio Telephone license in 1971.. Cause a Service Monitor was $1000's. Now go read how to use a BC-221 and we could meet and do better than commercial standards. Back then we'd use a heathkit oscilloscope and display the oscillator "standard" versus the unknown oscillator and produce a Lissajous pattern and using a twiddle stick, get the pattern to look like an "O" and try to stop it from rotating. In the Detroit area we were homebrewing 100.0 cycle PL''s and used a 5:3 Lissajous pattern against 60 cycles. Detroit Edison AC was our frequency standard.. Larry W8LM |
White NanoVNA-H Install Problem Help
Previously posted this to the QCX group. Don't ask why, I'm 85...8^)
................................................................... Well, I got one of the white plain vanilla NanoVNA-H units from Walmart for $39 and my son is printing an enclosure for me. I've no intention of using it above 60MHz so wasn't concerned about shields and etc. Just something to do some basic ham stuff. Now, I need some help. By itself, it seems to be doing what it should do. But... Attempting to use it with the nonovna-saver software a problem shows up. Scanning for a port produces nothing. The interconnect cable has a typical USB plug on one end and one of the newer micro USB connectors on the other. The computer does not recognize the VNA as a connected device; it does charge the battery. I've attached a PDF document with as much info as I could find that might provide some clues? If anyone can spot something from the PDF info or otherwise that would provide a solution, the info would be greatly appreciated. Thanks all... ---------------------------------- Update: I found this in a reply to another message I'd posted... <If you ordered an older model NanoVNA, with open sides, then you will need to use an OTG cable between the two devices.> And that's what I have so off to Amazon to order one OTG adapter... |
Re: android app?
On Sun, Jan 12, 2020 at 10:15 AM, Pete Buxton wrote:
I just opened web app on my Windows 10 computer in Chrome browser, but when I click on Connect, it says "No compatible devices found." ======================================================== Pete, You're quite right. Other members who have tried to run the web application under Windows have been told that a special driver is required which may or may not mess with some of your other serial port devices. Under Windows there are so many other better applications that the web application is seldom a necessity. For android the devices the web application, or apk if you can get it working, is the only game in town. If you are determined to get the web application running under windows I remember the driver is the same one I had to use when I installed my SDR dongle. - Herb |
Re: About cable delay compensation and NanoVna_Saver
#improvement
#test-jig
#tdr
#nanovna-saver
#measurement
On Sun, Jan 12, 2020 at 09:42 AM, Roger Need wrote:
There is a bug that in nanosaver. You have to multiply the delay by 10 and enter that into offest delay (under Calibration). So instead of 1690 you have to enter 16900 ps. ===================================================== Roger, Try the version Rune released yesterday. That bug had been reported before and I believe Rune was going to fix it in the next release. - Herb |
Re: android app?
I just opened web app on my Windows 10 computer in Chrome browser, but when I click on Connect, it says "No compatible devices found."
The NanoVNA splash screen says "GEN111.TAOBAO.COM" and using PuTTY on the serial COM port connects to it and reports: ch> info Kernel: 4.0.0 Compiler: GCC 5.4.1 20160919 Architecture: ARMv6-M Core Variant: Cortex-M0 Port Info: Preemption through NMI Platform: STM32F072xB Entry Level Medium Density devices Board: NanoVNA Build time: Aug 2 2019 - 16:40:01 Any ideas why the web app won't connect? Thanks! -Peter |
Re: #nanovna-saver help windows xp
#nanovna-saver
/g/nanovna-users/topic/nanovna_saver_and_windows_xp/69405140?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,40,69405140
-- *73, Lucio I0LYL Rome, Italy* |
Re: About cable delay compensation and NanoVna_Saver
#improvement
#test-jig
#tdr
#nanovna-saver
#measurement
NanoVna_Saver shows only lenght, not delay.
|
Re: About cable delay compensation and NanoVna_Saver
#improvement
#test-jig
#tdr
#nanovna-saver
#measurement
On Sun, Jan 12, 2020 at 04:45 AM, Leif M wrote:
I forgot the sign, + is surely not good. Is 1690ps good for a 32cm or one foot There is a bug that in nanosaver. You have to multiply the delay by 10 and enter that into offest delay (under Calibration). So instead of 1690 you have to enter 16900 ps. |
#nanovna-saver help windows xp
#nanovna-saver
Hi everyone, I want to use my nanovna with Windows XP I launch the nanovna-saver program but it gives me an error what procedures can I do to make it go
Roberto iw5bsf |
Re: android app?
On Sun, Jan 12, 2020 at 08:37 AM, <nanovnauser@...> wrote:
is there a nanovna app that works with ver 6.0.1? ========================================= Per previous group messages on the subject, below Android version 7.0 the only working solution has been to use the web based application at: but it requires that you are connected to the internet. - Herb |
Re: SimSmith - great, not only for Measuring resonance from coax far end.
W5DXP
Hans, DJ7BA, wrote:I do hope you have SimSmith. Excuse me for a non-finished answer. It's after midnight in Germany. I do have SimSmith and your experience and mine coincide, Hans. Ideally, we want the maximum available power transfer to occur at the antenna feedpoint. However, in a very low-loss system, we may have a system-wide *near-conjugate match* such that given a standard S-unit is 6 dB, the difference may be undetectable by the human ear. |
Re: Calibration help - above my pay grade.....
From: roncraig1@...
[] It is possible to tweak the synthesizer frequency setting to account for any TCXO tolerance. I don't think this function is written into the firmware and if it is not it might be something that could be put in future firmware. There would be a calibration register in Flash memory for freq offset and the firmware would calculate the required synthesizer setting offset to the desired freq. =========================================== Whilst the NanoVNA series are not designed as high stability frequency standards, I do agree that having the ability to set a "ppm" value for the master oscillator would be a very useful enhancement. Copied the suggestion to the NanoVNA-F group. David GM8ARV -- SatSignal Software - Quality software for you Web: Email: david-taylor@... Twitter: @gm8arv |
to navigate to use esc to dismiss