Re: Authorized Distributor with 6mo Warranty?
Here is a link to the one I purchased:
Marco
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On Sun, Oct 20, 2019, 4:32 PM zl2arl <colin.larsen@...> wrote: I tried to find AURSINC but my search foo must be broken, can someone post
up a link please.
Btw that TaoBao express site is a complete black hole, I'm cancelling that
order. Nothing has happened for more than a week!
Colin
On Mon, 21 Oct 2019, 05:42 n5kzw, <n5kzw@...> wrote:
I, also, bought the AURSINC unit and am quite happy with it. I don't
regret paying a little more as at the time of purchase, they were the only
ones I saw that were shielded.
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Anyone have a recommendation for a good battery to add to a unit missing one?
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Re: I added copper shields and it didn't turn out as expected ...
Mike, looking at the photo of the shields and how they mount, there is nothing that is visible to me that is obviously wrong.
I say this because the ch1 shield is mounted on pads that seem to be tied to ground with plenty of vias, so if there were a ground noise issue, I¡¯d expect noise to be improved, not worsened, when the shield is in place.
One thing I do notice, though, is that ch0 and ch1 both seem to have their own ground islands. And I¡¯m wondering if the back plate of the instrument was screwed in place when you noticed the improvement in ch1 noise when it¡¯s shield was removed. If the back plate is conductive (and from memory I think it¡¯s made of PCB material), then it¡¯s possible that the back plate is shorting all the grounds together through the standoffs and thus making a possible path for supply noise via rf ground. Compare the back plates of the two versions. Is one conductive and the other not?
Anyway...it¡¯s difficult to troubleshoot a problem long distance! Experiment, see what improves performance and what worsens it, and always compare these effects to how you think the changes ought to be affecting the performance.
Jeff, k6jca
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Re: Who has used the nanoVNA wiki to find information?
#wiki
Just found it and started reading. Found a nice mod for a DFU switch. Go
to junk box, find last switch, break switch. I¡¯ll have to find a new switch
but I am reading through the wiki now.
Thanks
Brad
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On Sun, Oct 20, 2019 at 6:15 PM r.h. verkuijl <pe1hlv@...> wrote: And i did
Op 19 okt. 2019 om 18:52 heeft erik@... het volgende geschreven:
?I did
--
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Dr. David Kirkby from Kirkby Microwave Ltd
On Mon, 21 Oct 2019 at 01:22, alan victor <avictor73@...> wrote: Hi Martin,
Yes. The only issue I see is the display of X as pF (or maybe nH or uH) in
any case, all cases will be the parallel equivalent admittance (impedance).
Rune and I discussed and in all cases he is implementing the equations you
highlighted. All the series complex and Q are a-ok. And the conversions are
a-ok.
Alan I mentioned some time ago that my HP LCR meter could show impedances in many ways - I think there mist be about 20 ways. It doesn¡¯t display S-parameters though. If its any help, I could do a single sweep then show every set of measurements it shows. If a Touchstone file with one data line was created to have the same parameters, it offers a way of comparing NanoVNA-Saver with the LCR meter. I am not suggesting that the NanoVNA software should implement all the ways that the HP LCR meter does. Some of the LCR meters on the market offer equivalent circuits with 3 or 4 components. I assume that requires looking at measured data over 2 or more frequency points. My obsolete HP 4284A can not do anything clever like that.?????? -- Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@... Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales, company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom
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Re: Is it possible to do a display driver swap?
To replace the display with ili9486, you need to modify the ili9341_init_seq[] at line 151 of ili9341.c and change the LCD width and height at various files. But if you want to replace with ili9488, there will be more work. Please see my post at /g/nanovna-users/message/5322You can find the places to change the LCD width and height at my change list. Just look for "LCD_*". Ken
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Re: I added copper shields and it didn't turn out as expected ...
Hmmm ... thanks for that. Let me play some more tomorrow and see what I can do.
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Re: I added copper shields and it didn't turn out as expected ...
Hi Mike_nano, Jeff...
One difference I note from prior photo's and shielding is the connection of the shield itself TO THE SMA CONNECTOR BODY. Each shield was returned to ground via the SAM. This connection could reveal an improvement and hence the presence of ground currents without that connection(s).
I am afraid that without the appropriate tools such as signal integrity simulation and EM, fooling around with shielding and cause and effect relations is like poking around in a dark closet with a sharp stick.
Alan
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Hi Martin,
Yes. The only issue I see is the display of X as pF (or maybe nH or uH) in any case, all cases will be the parallel equivalent admittance (impedance). Rune and I discussed and in all cases he is implementing the equations you highlighted. All the series complex and Q are a-ok. And the conversions are a-ok.
Alan
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Re: Is it possible to do a display driver swap?
ili9486 controller instead of the ili9341 Arduino folks do this sort of thing: Practicing on e.g. a blue pill with Arduino_STM32 would seem a safer approach.
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There are quite a number of wireless adapters with actual serial ports
AKA wireless device servers. Fewer with USB appear to be mostly for printers,
which is a different profile than for virtual COM ports. An Amazon customer reports that the US$65 Hawking HMPS1A works with a USB to serial converter. Power in is 5VDC, could be portable by USB power bank.
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Hi DougVL - I was (am) hoping someone might know of a wireless replacement for the USB
cable that goes from PC to NanoVNA. I think there is no 64-pin STM32 micro that supports USB OTG, so a bluetooth "dongle" that supports SCC profile and USB OTG is wanted. although if something becomes available it might be very popular. There are quite a number of wireless adapters with actual serial ports AKA wireless device servers. Fewer with USB appear to be mostly for printers, which is a different profile than for virtual COM ports. There may be a way to add such a communication capability to the NanoVNA,
but it's probably a major effort and not worthwhile.
Unless there turns out to be a lot of other requests for it! Moving the entire user interface to smartphone seems (IMO) desirable. It might be possible to wire a so-called USB host shield into nanoVNA that could drive existing bluetooth SCC dongles, but would require stripping out existing function to add firmware support. Particle Xenon uses a Nordic nRF52840 chip, which has more capable STM32 than in nanoVNA and includes bluetooth, so might make a great wireless nanoVNA-H 2.5 or 3.
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Re: Voltage sensing diode
I didn't have an SMT diode so just used an axial 1N4148. Can be done if one forms the leads with fine-point tweezers. It works fine.
Also, used the clipped lead wires to make little hooks for mini-grabbers on VDD and BOOT0, though with the latest firmware jumpering is no longer necessary for firmware loading..
73, --kv5r
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Re: Is it possible to do a display driver swap?
So what I want to do is using another display, for example a display with an ili9486 controller instead of the ili9341.
What I want to know is how hard it is to modify the software. Do I just replace the "ili9341.c" file for another one (maybe from the internet)? Or do I have to modify all of the firmware?
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Re: Voltage sensing diode
I have two Nanos and neither had the diode. I added the diode shown on the schematic an SD103AWS SMD part and then the battery indicator will work fine. Note it interferes with the battery connector on the board so I had to slice an angle off the bottom side of shell so it would fit back on the board.
I wonder of they left off that inexpensive diode because it interfered with that battery shell?
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Re: Voltage sensing diode
Eu adicionei o diodo 1N4148 (D2 proximo ao conector bateria).
Atualizei o FW 0.2.3-20191008
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Re: I added copper shields and it didn't turn out as expected ...
Jeff,,
Thanks for taking an interest. The answer is no. I'm very careful and took into account all the SMD parts locations. No, I don't see how I could have done that. I made sure that the edges of the copper were clearly on the ground plane outline.
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Re: I added copper shields and it didn't turn out as expected ...
Mike, any chance that the shield is shorting out C26 or C27?
Jeff, k6jca
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Re: I added copper shields and it didn't turn out as expected ...
That's a great case, I'm going to print one today :)
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On Mon, 21 Oct 2019, 11:04 Mike_nano, <biounit.mike@...> wrote: To the first nano I got (the one with the white 3D printed case) I added
my own carefully-made copper shields. I recently got another Nano (the one
with the orange case). It also came with no shields. However, I noticed
something - the second one has a better return loss with load for CH0 and a
better noise floor for CH1. Better than the Nano I had added shields to. I
did a lot of experimenting and calibrating and swapping of cables and
loads, and it's clear - the second one with no shields seems to behave
better in the two aspects noted before. Also, the two PCBs are identical -
no differences in design or components.
In the picture you see one of the shields removed because I wanted to see
what was going on. When I removed it, it also improved the CH1 response
(blue trace) more like the "orange" nano. I have not yet taken off the
other shield yet. I first wanted to ask the community to help me understand
this. It sure seems to me that the shields are not helping things. What am
I missing? Did I do something wrong?
.
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Oristo
Igor - PY3IG