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Re: Possible location of latest VNA source code??
My white Gecko clone hangs at the splash screen sometimes as well when running off the battery but never hangs when powered by the USB port.
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Does yours hang when powered by USB or battery? These devices use both 5v AND 3.6v supplies and I'm wondering if the vna will hang if the supplies don't come up quickly at the same time. Try disconnecting the battery and run it only from a USB source to see what happens. Since the 3.6v battery powers the uP, a defective one might cause issues. Regards, Larry On Tue, Jul 30, 2019 at 11:55 AM, DMR wrote:
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Re: Possible location of latest VNA source code??
DMR
Everything is smooth, my analyzer freezes on the splash screen. The code below does not fix this. Sometimes it works, sometimes every other time. I have an original firmware dump STM32, merged when I bought the device, there are no problems with freezing at the start. I see a problem not only with me. This happens on all tapes of firmware, 300, 900, 1300MHz. Is there a solution to this bug?
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Re: nano cases
Frank,
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Why don't you try something like what I drew for message /g/nanovna-users/message/608 ? Since I don't own a 3D printer (yet), I would assume my design could be printed on it's side. You could make the surface for the panel-mount N adapters thicker for rigidity and even design-in a few gussets or centre structure for more strength by the RF connectors. My original thinking on the design was that the sloped top and bottom surfaces would minimise back-front flexing. Just a thought. A note on that pesky USB port..., I use a Bird SK4000 antenna analyser at work. Bird originally designed the unit using only a micro USB port for charging and data transfer. It was a big design mistake - they replaced a lot of those ports. The next generation of the SK4xxx series had a barrel plug for charging in addition to the micro USB data port. Maybe you can design a case that also houses a flush-mount barrel jack for charging. NOTE- if anyone is thinking of adding an external non-usb charging port, please keep in mind that it will need to disconnect the USB +5V line when an external charger is inserted - or install a Schottky isolation diode so you don't try to push power back down the USB line. Regards, Larry On Mon, Jul 29, 2019 at 09:47 PM, Frank S wrote:
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Re: nano cases...
Dr. David Kirkby from Kirkby Microwave Ltd
On Tue, 30 Jul 2019 at 00:38, Frank S <ka2fwc@...> wrote:
I agree... to a point. This thing isn't a "real" VNA (in the commercial I am guessing that the N9914 is about 25 dB more expensive! I have been unlikely with FieldFoxs. Bought an N9923A reconditioned from Agilent. I found endless firmware bugs, then it had a hardware failure. I returned that to Agilent. Then I bought a used N9912A, which was DOA. The first NanoVNA I bought had a faulty screen. Hugen said they are delicate. There is also a larger (3.2¡±) version of that available. I am considering trying to fit a larger screen. -- Dr. David Kirkby, |
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Re: LabView Interface
Hello Joe and nice work on your LabVIEW interface to the nanoVNA. I'm wondering if you plan on sharing this with the group? I would be very interested in learning how you did what you did.
I have been successful in sending commands to the nanoVNA and getting it to respond using standard LabVIEW Serial Communications examples, but they are all still very crude and, as you said, the serial communications is a little sketchy at time. Anything that you would like to share would be greatly appreciated. Thanks and "nice job" on your vi. Larry |
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Re: nano cases
My original reason to design a case for this little thing, is the open sides are a place for something to get in and short the beast out. I never liked "test equipment" to get dirt or particles to get in.
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Since through the trouble of designing and printing a few to work the bugs out, I figured others might want to enclose theirs. To try and take this device and kluge it into a metal case I don't think would be worth it. Now, redesign it so it will fit in a case (with the appropriate connectors) in a metal box might be another way to go.?? For some people, they don't have the equipment/ ability to make the mods. On 7/29/2019 9:34 PM, kh6sky wrote:
I get it Frank. Boxing it up does have some downside. I think it depends on what you want to do with it, how much use/abuse it will receive, and whether or not your hands are more functional than catcher's mitts. For some of us this will be in the "fun-to-play-with" category. For someone like me it might be my only VNA. |
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Re: nano cases
I get it Frank. Boxing it up does have some downside. I think it depends on what you want to do with it, how much use/abuse it will receive, and whether or not your hands are more functional than catcher's mitts. For some of us this will be in the "fun-to-play-with" category. For someone like me it might be my only VNA.
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Re: Correct button?
Hi Alan,
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I just want to point out that the polynomial + delay + impedance method for characterising standards is itself just an approximation. In this day and age (of cheap storage) it is simpler to just sweep the standards on a calibrated VNA, get an s-param file for each one and use that data in the calcs - with some interpolation for the in-between frequencies. This gives the highest accuracy as there is no modelling error. It also means you can use any old standard you like. The polynomial models don't fit poorly made standards very well over a wide frequency range, hence the need for high quality expensive parts. However I'm not sure if this device has the storage available to do it this way, if not the old school approach might be the best way. Regards, Roger On Tue, 30 Jul 2019 at 08:49, alan victor <avictor73@...> wrote:
Thanks! That is helpful. The fact that the polynomial code to describe the |
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Re: Possible location of latest VNA source code??
Lapo Pieri
Hi,
11:32 Mon 29 Jul 19 , DMR wrote: After compilation it works exactly the same as yours.Where are these vars? Hi hugen! Share the full working code please.I take the full code from here: Are we talking about different source code? Lapo, IK5NAX |
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Re: nano cases...
I agree... to a point. This thing isn't a "real" VNA (in the commercial respect). I don't know if I would have used it when I schlepped up a water tower in Melbourne Australia. I had a Keysight N9914 :-)
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On 7/29/2019 10:19 AM, Burt K6OQK wrote:
Personally, I'd rather see this instrument in a tablet size, something I can easily see; in a real metal box with Type-N connectors and sturdy switches and push-buttons.?? My need is for an instrument that I can carry to antenna sites for broadcast antenna work.?? I understand where some folks like tiny pocket size instruments, not sure why, but I'm probably going to go to something like an HP e5061B - a totally different area of an instrument.?? I like the 8753c or ES but they are pretty big and heavy for schleping to transmitter sites. |
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Re: Smith chart impedance printout
Lapo Pieri
Hi,
19:27 Mon 29 Jul 19 , alan victor wrote: Sure Lapo. That is great. However they are all practical representations. In fact why stop there. You could convert the result to its parallel equivalent admittance and provide that as well.I think I have to study the code a bit more to make more complex mods, stay tuned ;-) Lapo, IK5NAX |
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Re: Smith chart impedance printout
Lapo Pieri
16:07 Mon 29 Jul 19 , alan victor wrote:
Wait a second. The display is available as R+jX. Just switch to And if you desire you can dedicate trace 0 to a Smith plot while youNo, polar format display coefficient of reflection, not impedance! Lapo, IK5NAX |
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Re: Smith chart impedance printout
Hi Lapo,
Wait a second. The display is available as R+jX. Just switch to polar.format. And if you desire you can dedicate trace 0 to a Smith plot while you dedicate trace 1 to a polar plot. Of course in polar format you will have to multiply the polar vector by Zo of the chart/system which of course is 50 ohms. Alan |
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Re: Correct button?
Thanks! That is helpful. The fact that the polynomial code to describe the open is present implies he was aware of the situation and at this point elected to put it aside. So for all intent and purpose, the loads are assumed to be ideal and that tends to agree with the final sweep to check the loads after cal. The check returns them to be IDEAL... And they are anything but ideal as that is the electrical-physical nature of a SMA connector.
Alan ________________________________ From: [email protected] <[email protected]> on behalf of Roger Henderson <hendorog@...> Sent: Monday, July 29, 2019 8:32 PM To: [email protected] <[email protected]> Subject: Re: [nanovna-users] Correct button? I checked the code repo's posted and this is what I think the situation is with the standards: The load is assumed to be perfect - i.e. the assumption is that nothing is reflected from the load. The open is assumed to have a single C0 capacitance term of 50e-15F The short is either assumed to be perfect, or is assumed to be 180degrees away from the open. I am not quite sure on that. There is some unused code which looks to be intended to create a C0,C1,C2,C3 model of the open, but it is not used. Roger On Mon, 29 Jul 2019 at 14:37, alan victor <avictor73@...> wrote: You are correct and I confirmed on the big box, that is the function |
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Re: Correct button?
I checked the code repo's posted and this is what I think the situation is
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with the standards: The load is assumed to be perfect - i.e. the assumption is that nothing is reflected from the load. The open is assumed to have a single C0 capacitance term of 50e-15F The short is either assumed to be perfect, or is assumed to be 180degrees away from the open. I am not quite sure on that. There is some unused code which looks to be intended to create a C0,C1,C2,C3 model of the open, but it is not used. Roger On Mon, 29 Jul 2019 at 14:37, alan victor <avictor73@...> wrote:
You are correct and I confirmed on the big box, that is the function |
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Re: Smith chart impedance printout
Sure Lapo. That is great. However they are all practical representations. In fact why stop there. You could convert the result to its parallel equivalent admittance and provide that as well.
I suspect that if you are doing antenna work and wish to design an impedance matching network, YES. The usual process is to specify the LOAD, the antenna as a complex Z or Y and not as a R and C/L unit. However, a little calculator can handle the conversion. But you are right, it would just be more convenient to have the vna spit it out. I think best to provide this as a user selection menu item. What do you think? 73' Alan ________________________________ From: [email protected] <[email protected]> on behalf of Lapo Pieri <ik5nax@...> Sent: Monday, July 29, 2019 5:51 PM To: nanovna-users <[email protected]> Subject: [nanovna-users] Smith chart impedance printout Hi, I think that Smith chart presentation of impedance as <real_part>[ohm] <series cap or ind>[F|H] is not practical in many case of use. So I decide to modify the code to show impedance in <real_part>+/-j<imag_part> format, you can find the patch to plot.c to obtain this. If I found a bit of time I could split Smith chart in two, one as original and one as just proposed. Do you think it worth? Lapo, IK5NAX -------- diff --git a/plot.c b/plot.c index 10074c3..c5c92e5 100644 --- a/plot.c +++ b/plot.c @@ -576,16 +576,22 @@ gamma2imp(char *buf, int len, const float coeff[2], uint32_t frequency) // float z = sqrtf(zr*zr + zi*zi); int n; - n = string_value_with_prefix(buf, len, zr, S_OHM[0]); - buf[n++] = ' '; + n = string_value_with_prefix(buf, len, zr, '\0'); + if(zi<0) + buf[n++]='-'; + else + buf[n++]='+'; + buf[n++]='j'; + string_value_with_prefix(buf+n, len-n, fabs(zi), S_OHM[0]); - if (zi < 0) { - float c = -1 / (PI2 * frequency * zi); - string_value_with_prefix(buf+n, len-n, c, 'F'); - } else { - float l = zi / (PI2 * frequency); - string_value_with_prefix(buf+n, len-n, l, 'H'); - } + + /* if (zi < 0) { */ + /* float c = -1 / (PI2 * frequency * zi); */ + /* string_value_with_prefix(buf+n, len-n, c, 'F'); */ + /* } else { */ + /* float l = zi / (PI2 * frequency); */ + /* string_value_with_prefix(buf+n, len-n, l, 'H'); */ + /* } */ } void |
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Re: Possible location of latest VNA source code??
Hugen has already committed his changes back to edy555's original github repository.
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Have a look at On Mon, Jul 29, 2019 at 02:32 PM, DMR wrote:
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