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Re: NanoVNA-Saver 0.1.0
Larry, thank you very much. I've found it!
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Roy WA0YMH On Wed, Oct 2, 2019, 7:05 PM Larry Rothman <nlroth@...> wrote:
Firmware archive in the files section |
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Re: NanoVNA-Saver 0.1.0
Firmware archive in the files section
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On Wed, 2 Oct 2019 at 7:54 PM, Roy Appleton<twelveoclockhigh@...> wrote: Where can I find a copy of the "CLEAR_MEMORY_DFU" file? Thanks, Roy WA0YMH On Wed, Oct 2, 2019, 6:44 PM Larry Rothman <nlroth@...> wrote:
Bob,You don't need a torque wrench for this device - it's just not that |
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Re: NanoVNA-Saver 0.1.0
Where can I find a copy of the "CLEAR_MEMORY_DFU" file?
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Thanks, Roy WA0YMH On Wed, Oct 2, 2019, 6:44 PM Larry Rothman <nlroth@...> wrote:
Bob,You don't need a torque wrench for this device - it's just not that |
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Re: NanoVNA-Saver 0.1.0
Bob,You don't need a torque wrench for this device - it's just not that critical IMO.?An alternative would be the small 3d printed rings that were discussed a couple of weeks ago.?Also, take the front cover off the display and ensure that the SMA PCB mounts on that side of the board are soldered. Most aren't.?
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RegardsLarry On Wed, 2 Oct 2019 at 7:00 PM, Bob Albert via Groups.Io<bob91343@...> wrote: Well Herb I have no idea how to upgrade the firmware.? I do have the sharp program on my PC if that helps. Anyway I am having a blast with this amazing unit.? I can't believe it's basically as good as boat anchor units costing 100 or more times as much.? And even includes a display and cal kit! I was ready to order a different unit from a different vendor but that doesn't appear to be necessary.? I am going to shout from the rooftops about this great instrument. Sure it has its limitations but is wonderful nonetheless.? I am getting displays that, while not totally in agreement with my other gear, still look very believable.? Even the shape of the SWR vs frequency curves are similar to my fancy VNA.? And with the help of the sharp program I can print results. I am still learning about saving and recalling and such.? I have some SMA hardware on order that will simplify some of my testing.? I am still agonizing over the cost of a torque wrench; so far I haven't gotten one. Another impressive characteristic is the accuracy of the frequency.? Putting it into CW mode generates a solid, precise signal.? I wonder about the amplitude; I will see about measuring it on my SA.? Perhaps it will do as a signal generator.? It's well shielded, as I can't hear its signal with nothing connected to it. Bob On Wednesday, October 2, 2019, 03:17:32 PM PDT, hwalker <herbwalker2476@...> wrote:
Bob, If you ever decide to upgrade your firmware you may run into something similar.? My second NanoVNA arrived with only the 2 trace firmware installed.? When I tried to upgrade to the 4 trace firmware it wouldn't take correctly.? The solution was to first install CLEAR_MEMORY_DFU and then install the 4 trace DFU.? Its not always necessary, but I now use it as a matter of course to prevent artifacts left over from the previous install from causing hard to track down problems. Herb |
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Re: edy555 design notes on CALIBRATION sets
Hi
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Yes that's great that we can now look at all these components to see just how good they are/,were. Carry on and publish your results. We will all be interested I'm sure. A On Thu, 3 Oct 2019, 00:10 alan victor, <avictor73@...> wrote:
Several years ago I investigated potentiometers with the lowest possible |
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Re: NanoVNA-Saver 0.1.0
Bob Albert
I just measured about -10 dBm into 50 Ohms at both 100 MHz and 10 MHz.? Not enough to be illegal.
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Bob On Wednesday, October 2, 2019, 04:32:43 PM PDT, Alan Lloyd <alanthebass37@...> wrote:
Hmm. I measured 100mV PK-PK into 50 ohms at 50 kHz. My scope drops off at high frequencies (as do all). Output is, of course, a square wave. ? A On Thu, 3 Oct 2019, 00:00 Bob Albert via Groups.Io, <bob91343= [email protected]> wrote: ? Well Herb I have no idea how to upgrade the firmware.? I do have the |
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Re: NanoVNA-Saver 0.1.0
Hmm. I measured 100mV PK-PK into 50 ohms at 50 kHz. My scope drops off at
high frequencies (as do all). Output is, of course, a square wave. ? A On Thu, 3 Oct 2019, 00:00 Bob Albert via Groups.Io, <bob91343= [email protected]> wrote: Well Herb I have no idea how to upgrade the firmware. I do have the |
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Re: edy555 design notes on CALIBRATION sets
Several years ago I investigated potentiometers with the lowest possible reactance up through 30 MHz. I found the Allen Bradley TYPE J and specifically a 1 k ohm P/N JA1G044P102B exceptionally good.
This pot demonstrated a range of R from nearly a short circuit to 1 k which moved EXACTLY along the real axis on the Smith Chart display of my VNA; swept through 30 MHz. I was amazed of the low parasitic reactance displayed. I'll see if I can find one to sweep and display. Alan |
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Re: NanoVNA-Saver 0.1.0
Bob Albert
Well Herb I have no idea how to upgrade the firmware.? I do have the sharp program on my PC if that helps.
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Anyway I am having a blast with this amazing unit.? I can't believe it's basically as good as boat anchor units costing 100 or more times as much.? And even includes a display and cal kit! I was ready to order a different unit from a different vendor but that doesn't appear to be necessary.? I am going to shout from the rooftops about this great instrument. Sure it has its limitations but is wonderful nonetheless.? I am getting displays that, while not totally in agreement with my other gear, still look very believable.? Even the shape of the SWR vs frequency curves are similar to my fancy VNA.? And with the help of the sharp program I can print results. I am still learning about saving and recalling and such.? I have some SMA hardware on order that will simplify some of my testing.? I am still agonizing over the cost of a torque wrench; so far I haven't gotten one. Another impressive characteristic is the accuracy of the frequency.? Putting it into CW mode generates a solid, precise signal.? I wonder about the amplitude; I will see about measuring it on my SA.? Perhaps it will do as a signal generator.? It's well shielded, as I can't hear its signal with nothing connected to it. Bob On Wednesday, October 2, 2019, 03:17:32 PM PDT, hwalker <herbwalker2476@...> wrote:
Bob, If you ever decide to upgrade your firmware you may run into something similar.? My second NanoVNA arrived with only the 2 trace firmware installed.? When I tried to upgrade to the 4 trace firmware it wouldn't take correctly.? The solution was to first install CLEAR_MEMORY_DFU and then install the 4 trace DFU.? Its not always necessary, but I now use it as a matter of course to prevent artifacts left over from the previous install from causing hard to track down problems. Herb |
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Re: NanoVNA-Saver: Testers wanted
Hello Rune,
If you haven't done so already, please add my name to your list of Alpha testers if you would like. I will be testing on a Dell Laptop computer running Windows 10 and an iMac under Mojave 10.14.6. I understand that this is a chance to test for program bugs and not recommend new features. I agree. I do believe the it's time to nail down at least one foot. That way you can only run in a small circle! Thanks for all the work you've done on this incredible project. Larry |
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Re: NanoVNA-Saver 0.1.0
Bob,
If you ever decide to upgrade your firmware you may run into something similar. My second NanoVNA arrived with only the 2 trace firmware installed. When I tried to upgrade to the 4 trace firmware it wouldn't take correctly. The solution was to first install CLEAR_MEMORY_DFU and then install the 4 trace DFU. Its not always necessary, but I now use it as a matter of course to prevent artifacts left over from the previous install from causing hard to track down problems. Herb |
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Re: edy555 design notes on CALIBRATION sets
I made a page about this:
Basically, unbalanced bridge sensitivity is non-linear; for bridges balanced @ 50 Ohms, signal amplitude difference from 0 to 50 is the same as from 50 to 150. Signal change from 500 to 1000 Ohms is only 10% of change from 0 to 1000 Ohms, so far more sensitive near 50 Ohms, and "calibrating" with a different LOAD does not help. |
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Re: Installed recent firmware - was this a big mistake?
In reality, USB does not work that way. Here are "real" supported USB speeds:
USB 1.0/Low-Speed: 1.5 Megabits per second (Mbps) USB 1.1/Full-Speed: 12 Mbps. USB 2.0/Hi-Speed: 480 Mbps. USB 3.0/SuperSpeed: 5 Gbps. USB 3.1/SuperSpeed: 10 Gbps. Setting some bps is supported for virtual COM (AKA CDC device) to chips (e.g. FTDi) at the other end which interface USB to real serial (RS-422 or 232 or whatever).. There is no such interface at the STM32 chip in nanoVNA,. Speed is determined by which USB speed gets negotiated at plugin detection time and buffer sizes implemented. |
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Re: edy555 design notes on CALIBRATION sets
What is the Z range of the NanoVna? I characterized a 500 ohm pot with another Z instrument with the pot set to 500 ohms. At 10 MHz the pot looked something like a resistance 480 ohms with about 80 ohms of reactance. The NanoVna was off by about 20% for R and about 50% off for X. I did some more of this and found the results looked better but only below about 250 or 300 ohms. I know the NanoVNA is not an LCR instrument but I was hoping to see something closer up to about 1K.
I read some discussions about cal kits and all. I do most of my tinkering at HF and use BNC most of the time so I made up a simple BNC short and leave the cable open for an open and attach a 50 ohm load via BNC adpaters for the load. The results are good enough and I do the same for quick measurements at work using the 8753 basically the same way. In any case, none of the connectors I use at home or use at work are type N or APC 3.5 or APC 7 that are supported by real cal kits. Everything is BNC, SMB or SMA or other small connectors in that family. I've had my NanoVna for about a month now and having a great time doing swept meas'ts at home instead of using my ancient GR bridges. I will not scrap the old bridges because each one has a strength over the others including the NanoVNA. |
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Re: Installed recent firmware - was this a big mistake?
Hello Rune-
First, thanks for the very useful NanoVNA-Saver application! Earlier in this thread you mentioned setting the data rate at 115200 bps. This is 2nd hand information- somewhat anecdotal- but apparently plugging multiple devices (mouse, keyboard, etc.) into a USB hub can alter/decrease the data rate for other devices on the hub. I wonder if this can explain any of the cases of reported NanoVNA data loss. I first heard of this over at the SDR-Radio Groups.io list. I realize that 115200 is 'quite slow' by nominal USB standards. 73, Joe F. KC8RKL |
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Re: NanoVNA-Saver 0.1.0
Bob Albert
Herb,
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You nailed it!? I did the reset and calibration and now the unit works! I am not so delighted with what I see, as it isn't that close to my static measurements.? However, the unit now behaves as I think it should.? I get believable SWR and Smith presentations. Thank you so much; I really didn't want to put this thing under the soldering iron. Bob On Wednesday, October 2, 2019, 01:20:07 PM PDT, hwalker <herbwalker2476@...> wrote:
Bob, One other thing to try before you start looking at the hardware. The first NanoVNA I bought came pre-calibrated and was ready to go out of the box.? A second cheaper? NanoVNA that I bought came un-calibrated and behaved much as you described.? I went through the calibration procedure and saved it to location "0" and the Smith chart display was still pinged to the righthand side regardless of termination.? I read a different calibration procedure that said to first select "RESET" under the "CAL" menu and then perform the calibration procedure and save to location "0".? After adding that step, the second NanoVNA worked like a champ.? You may have already done this but some beginning users skip performing the "RESET" step first. Herb |
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Re: How does VNA get the phase angle of S11
Thanks for asking the question. I am familiar with them methods of old. Like sala nimi outlined. The R ch and the A and B ch's are down converted to a low IF and these are applied to the inputs of phase detectors. With the new synthesizer IC's available today the phase of signals can be shifted and the phase can be indirectly determined. I am hoping someone will give us the details!
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Re: NanoVNA-Saver 0.1.0
Hi Bob,
You will find everything in the forum Wiki and Files. Calibration is probably required, please read the latest manual on how to do it. There you can get answers to many possible questions. I'm talking about this: /g/nanovna-users/files/NanoVNA%20User%20Guide-English-reformat-Oct-2-19.pdf 73, Gyula |
Oristo
Gyula Molnar
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