Re: First PCB pictures of the V2
Hi,
Could you please share the STL?
Cheers
*73 de Lu¨ªs, CT2FZI*
*QRV @ 145.300 MHz | **CQ0VMST (VHF REP Monsanto)*
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On Fri, 27 Mar 2020 at 19:15, <ersoz@...> wrote: Made a housing for the new NanoVNA V2.
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Re: First PCB pictures of the V2
Made a housing for the new NanoVNA V2.
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If you're good at soldering surfacemount (and have a microscope or by magnifying glass, try re-flowing the PCB solder pins on the nanovna's USB-C connector.If either of the data lines is not connecting, you will see that error.Remove the battery first if you're going to try this.
Conversely, get an old USB cable, strip? the wires at one end and solder directly to the data lines at the 2 small buffer resistors (22ohm I think).If it doesn't work one way, swap the data lines - BUT under no circumstances allow 5V on to the datalines - you'll kill the interface. USB datalines have 3V signals.
I hope this helps.
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On Friday, March 27, 2020, 1:05:33 p.m. GMT-4, i2NDT Claudio via Groups.Io <i2ndt@...> wrote:
well...I duly disinstalled the drivers several times...and actually USBDeview didn't find any driver related to STMsomething.
yesterday I spent the whole afternoon with uncle Google trying to find some help about that "unknown device" error code...but I was unsuccesful...maybe didn't make the right questions!
I also checked the group...
I guess I am the first one with this problem!
and, moreover, I also checked the H4 on another PC just rebuilt ex-novo with windows 10 PRO. same result: "Unknown device"!
i2NDT Claudio
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On Fri, Mar 27, 2020 at 10:05 AM, i2NDT Claudio wrote:
...I also checked the H4 on another PC just rebuilt ex-novo with windows 10 PRO. same result: "Unknown device"!
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Claudio,
Until you are able to eliminate the USB-C to USB-A cable as the culprit (per hugen's suggestion), you may be transferring the problem to each PC you are trying to use.
Good luck.
- Herb
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well...I duly disinstalled the drivers several times...and actually USBDeview didn't find any driver related to STMsomething.
yesterday I spent the whole afternoon with uncle Google trying to find some help about that "unknown device" error code...but I was unsuccesful...maybe didn't make the right questions!
I also checked the group...
I guess I am the first one with this problem!
and, moreover, I also checked the H4 on another PC just rebuilt ex-novo with windows 10 PRO. same result: "Unknown device"!
i2NDT Claudio
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Let's be nice people.
Most people assume the device they are working with is at fault, not the underlying platform (Windows in this case).
Even a good search won't return the results you need if your premise is wrong. So please save the finger pointing for something more serious than "Why didn't he just google it?"
Just saying; it is of little profit to post "google it".
Cheers, Ed H. KT4ED
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On 3/27/2020 7:31 AM, Gyula Molnar wrote: this can also be a solution. The problem is not with nanovna, but with the pc operating system. If you know google you shouldn't have asked the question here.
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Moderated
Re: Another off-topic about Smith chart
Actually, I should have said, the real axis coordinates are scaled as the real part of (1+¦£)/(1-¦£), i.e., the normalized impedance Z_L / Z_o .
-- Aldo
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On 3/27/2020 9:39 AM, Aldo Cugnini via Groups.Io wrote: Exactly. The real axis coordinates are scaled as (1+¦£)/(1-¦£), i.e., the real part of the normalized impedance Z_L / Z_o .
-- Aldo
On 3/26/2020 8:52 PM, WB2UAQ wrote:
The Smith Chart is a plot of the reflection coefficient where it's magnitude covers 0 to 1 having a phase angle from 0 to 360 degrees (0 to 2pi radians) (vector....mag and phase angle).? The impedances, the three circles, correspond to mag and phase of the reflection coefficient.? Basicallya these three circles are over laid onto the reflection coefficient.
I agree that it is not easy to be very accurate.?? Tough to mark and read off the impedance coordinates in many places on the chart.
--
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*Aldo Cugnini*
/908-867-8550/
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Re: Another off-topic about Smith chart
Hi all, A bit late in posting this, but to all those who are just starting out, and having a learning curve approaching the Smith Chart, I have put together an introductory article.? You can find it here: 73's Aldo W2AGC
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On 3/27/2020 9:39 AM, Aldo Cugnini via Groups.Io wrote: Exactly. The real axis coordinates are scaled as (1+¦£)/(1-¦£), i.e., the real part of the normalized impedance Z_L / Z_o .
-- Aldo
On 3/26/2020 8:52 PM, WB2UAQ wrote:
The Smith Chart is a plot of the reflection coefficient where it's magnitude covers 0 to 1 having a phase angle from 0 to 360 degrees (0 to 2pi radians) (vector....mag and phase angle).? The impedances, the three circles, correspond to mag and phase of the reflection coefficient.? Basicallya these three circles are over laid onto the reflection coefficient.
I agree that it is not easy to be very accurate.?? Tough to mark and read off the impedance coordinates in many places on the chart.
--
------------------------------------------------------------------------
*Aldo Cugnini*
/908-867-8550/
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Moderated
Re: Another off-topic about Smith chart
Exactly.? The real axis coordinates are scaled as (1+¦£)/(1-¦£), i.e., the real part of the normalized impedance Z_L / Z_o .
-- Aldo
toggle quoted message
Show quoted text
On 3/26/2020 8:52 PM, WB2UAQ wrote: The Smith Chart is a plot of the reflection coefficient where it's magnitude covers 0 to 1 having a phase angle from 0 to 360 degrees (0 to 2pi radians) (vector....mag and phase angle). The impedances, the three circles, correspond to mag and phase of the reflection coefficient. Basicallya these three circles are over laid onto the reflection coefficient.
I agree that it is not easy to be very accurate. Tough to mark and read off the impedance coordinates in many places on the chart.
--
------------------------------------------------------------------------
*Aldo Cugnini*
/908-867-8550/
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GREAT Article, Aldo - Thanks!
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On Friday, March 27, 2020, 9:31:15 a.m. GMT-4, Aldo Cugnini <acugnini@...> wrote:
Hi all,
A bit late in responding, but to all those who are just starting out,
and having a learning curve approaching the Smith Chart, I have put
together an introductory article.? You can find it here:
73's
Aldo
W2AGC
--
------------------------------------------------------------------------
*Aldo Cugnini*
/908-867-8550/
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Hi all,
A bit late in responding, but to all those who are just starting out, and having a learning curve approaching the Smith Chart, I have put together an introductory article.? You can find it here:
73's
Aldo
W2AGC
--
------------------------------------------------------------------------
*Aldo Cugnini*
/908-867-8550/
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this can also be a solution. The problem is not with nanovna, but with the pc operating system. If you know google you shouldn't have asked the question here.
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i had this issue after a windows update,had to use system restore then it was ok,that was using win 7 64 bit.
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after removing it, install the driver, don't wait for your computer to look for a driver.
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Hi Claudio, I think you should read and apply this: /g/nanovna-users/message/7284You may also need to reboot your PC and nanovna. (Turn off then turn on.) Hope this helps. 73, Gyula HA3HZ
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Hugen Can I suggest you use the same values of R25 and R24 in the attenuator circuit for the CH1 input as those used in for the reference SA612? And then set R22 to come to 50 ohm? This will reduce the amount of calibration deduced compensation needed for S21 measurements and thus noise. Interesting you found the unbalance less noisy. In my experiments I found the balanced less noisy. Not sure why????. Possibly because I was doing experiments on an unshielded PCB and we have rather strong DAB and mobile phone signals here and in a balanced configuration these could be eliminated because of the SA612 differential input???? -- NanoVNA Wiki: /g/nanovna-users/wiki/homeNanoVNA Files: /g/nanovna-users/filesErik, PD0EK
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thanks Hugen!
but unfortunately I haven't a spare cable and can't go out to buy one: thanks COVID-19! hahaha
I checked the socket and it's OK: I didn't need to enlarge the hole of the case.
Claudio
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Moderated
Re: Another off-topic about Smith chart
In the immortal words of Arte Johnson...verry interesting...
In over 20 + replies only handful actually answered or came close to answer my question.
As of now , here are MY observations.
The Smith chart scale is logarithmic - from "zero" to 1 and from 1 to "10" .
(The boundaries / end points can be labeled to your liking - zero or infinity - computer does identify log(0) as "inf".)
The "accuracy" of computer generated chart is as good as the actual graphical display.
Coding the graph "circles" - using OpenGL (C) - is not trivial when dealing with values approaching "infinity".
( But that is definitely off topic subject here ).
Appreciate all comments.
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Moderated
Re: Another off-topic about Smith chart
The Smith Chart is a plot of the reflection coefficient where it's magnitude covers 0 to 1 having a phase angle from 0 to 360 degrees (0 to 2pi radians) (vector....mag and phase angle). The impedances, the three circles, correspond to mag and phase of the reflection coefficient. Basicallya these three circles are over laid onto the reflection coefficient.
I agree that it is not easy to be very accurate. Tough to mark and read off the impedance coordinates in many places on the chart.
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Another solution comes from the suggestion of Massimo. Changing the input of SA612A to single-ended can eliminate the influence of the capacitance of one of the input pins. Maybe this modification is more appropriate, I am testing.
¡°
R22 = 68 ohm 0603 1% resistor
R23 = 0ohm 0603 shunt
R24 = 120ohm 0603 1% resistor
R25 = 22ohm
Note that it has changed form differential to single ended, just because it was a nonsense. The driving signal of the SA612D mixer was in-phase on both sides of R25, so there was no advantages using that configuration. I found this configuration less noisy indeed and best matching the CH1 input port impedance for higher frequencies, that thanks to the higher value of R22 that is the one which influence more the capacitive behaviour of the CH1 input port trought the mixer input capacitance.
¡±
hugen
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CT2FZI
@blackmagic
Aldo Cugnini
Gyula Molnar