Re: Simple way to produce calibration standards
#calibration
Why not use ordinary BNC hardware with an adapter?? Maybe not good all the way to 900 MHz but fine for casual use.
Bob
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On Sunday, November 24, 2019, 10:35:34 AM PST, Daniel Marks <profdc9@...> wrote:
I was not very satisfied with the quality of the calibration standards I ordered off of ebay, so I made my own out of PCB edge mount male SMA connectors as shown here:
The picture is attached.? It is simple.? One of them is unmodified for the open, you solder a wire between the center conductor and two PCB edge mounts for the short, and use two 0805 or 1206 100 ohm resistors, soldering the resistors from the center pin to the edge mounts.
A pack of 5 of the connectors cost me under $2 on ebaay.
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I was not very satisfied with the quality of the calibration standards I ordered off of ebay, so I made my own out of PCB edge mount male SMA connectors as shown here:
The picture is attached. It is simple. One of them is unmodified for the open, you solder a wire between the center conductor and two PCB edge mounts for the short, and use two 0805 or 1206 100 ohm resistors, soldering the resistors from the center pin to the edge mounts.
A pack of 5 of the connectors cost me under $2 on ebaay.
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Re: Sign of format LINEAR in the NanoVNA
I am using Hugen's latest AA FW but have also checked with QRP's latest. I am
under the impression that the format LINEAR is equal to rho, the absolute
value (modulus) of gamma (S11),
and that the formats REAL and IMAG are the real- and imaginary parts of gamma.
What bothers me is that in both Hugen's FW and QRP's FW the sign of format
LINEAR is negative, whereas I expect that an absolute value is positive per
definition. Have I got it wrong? Please help me. CH0 LINEAR is displayed on device as positive small values with QRP 0.4.3 firmware. Need to set e.g. REFERENCE POSITION 1 and SCALE/DIV .001x1
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Sign of format LINEAR in the NanoVNA
I am using Hugen's latest AA FW but have also checked with QRP's latest. I am under the impression that the format LINEAR is equal to rho, the absolute value (modulus) of gamma (S11),
and that the formats REAL and IMAG are the real- and imaginary parts of gamma. What bothers me is that in both Hugen's FW and QRP's FW the sign of format LINEAR is negative, whereas I expect that an absolute value is positive per definition. Have I got it wrong? Please help me.
Regards/Torbjorn
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Hi Oristo,
I uploaded it again. You can get it from the same link:
neb
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it requires Android 7+ I have not tried, but: Amazon Fire 7 tablet is on sale for US$30 My understanding that it is based on Android 7+ and can be tweaked to use Play Store apps and supports USB OTG .. so may work for Android NanoVNA WebApp
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Hi neb - The software is under development, but if you are interested you can
get it from here: That URL expired after 1 week.
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Thanking everyone for their responses. I was able to resolve the issue by performing a screen calibration using the Touch Cal function in the menu
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Hello Norbert,
looks like a bug to me - I'll be sure to check it out and try to get it
fixed :-)
--
Rune / 5Q5R
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On Sun, 24 Nov 2019 at 13:32, Norbert Kohns <norbert.kohns@...> wrote: Hi Rune,
the reset reference button is not working for the S11 & S21 LogMag (dB)
window (pls see attachments).
If I hit reset reference nothing happens on this window. Reset right on
this window works fine.
Is this per design or a bug?
Kind regards
Norbert, DG1KPN
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I placed an order on EBay for a low priced NanoVNA from dowjors3236. He did not have a lot of feedback at the time.
I knew I would get either the VNA or my money back.
Got an email that it was going to shipping and a tracking number.
Kept checking the tracking number and it never said shipped.
When the delivery window ended, I filed with EBay, after leaving negative feedback for vendor.
After I filed, vendor requested EBay open a case.
The next day I received a refund because tracking number was not valid.
Vendor now has a lot of negative feedback, do not know why EBay has not booted him.
At least I got my refund.
Glenn
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On 11/23/2019 9:52 AM, Ron Bussiere wrote: Dave, excellent information. I have 3000+ purchases on eBay. Lots of items from China. I always do as you suggest, check the Seller's Feedback and number of sales.
Just one last thought...¡ Recently, I purchased an 'F' model from a store in China. It was the 'usual' price, around $140. Excellent Feedback (99.3%) on 20,000+ sales. MY problem was: I ordered it on the last day of September. I was told by the Seller that the entire country goes on 'holiday' the first week of October, including all shipping, etc.
Sure enough, weeks went by with no updates on the Tracking Number. I contacted the Seller and he told me he couldn't track it either.
I was given a refund very quickly and ordered another 'F' from another Seller, for the same price. It showed up within the expected time.
ron
N4UE
--
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Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
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Hi Rune,
the reset reference button is not working for the S11 & S21 LogMag (dB) window (pls see attachments).
If I hit reset reference nothing happens on this window. Reset right on this window works fine.
Is this per design or a bug?
Kind regards
Norbert, DG1KPN
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Hello I just received my NanoVNA -f (4.3 inch display) . When I try to select a menu option The options disappear. ( No green highlighting unless you use the jog wheel) Is a stylus needed? Bob ============================= Bob, You need the nanoVNA-F group: /g/nanovna-fDavid -- SatSignal Software - Quality software for you Web: Email: david-taylor@... Twitter: @gm8arv
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Re: Running NanoVNA on MacBook Pro
Have problem shown up specifically with nanoVNA Saver? I am running Pyton 3.8 and it appears to be working just fine.
-rick
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On Nov 23, 2019, at 16:07, Dana Shtun <ve3dss@...> wrote:
Wayne, just don¡¯t use Version 3.8 of python¡its buggy¡
I have this running fine on Catalina with v 3.7 of python.
Dana VE3DS
On Nov 19, 2019, at 17:34, vk6eh@... wrote:
hi all, forgive me if I missed any previous post on this subject.
Is it possible to run a nanoVNA on a MacBook, any problems, how to, s/ware etc ?
thanks
Wayne VK6EH
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Bob did you remove the plastic protective cover from the screen?
I just mine today too and it's wonderful!
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On Sat, Nov 23, 2019 at 9:11 PM <rh1530@...> wrote: Hello
I just received my NanoVNA -f (4.3 inch display) . When I try to select
a menu option
The options disappear. ( No green highlighting unless you use the jog
wheel)
Is a stylus needed?
Bob
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Hello
I just received my NanoVNA -f (4.3 inch display) . When I try to select a menu option
The options disappear. ( No green highlighting unless you use the jog wheel)
Is a stylus needed?
Bob
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Re: New 5,1 Firmware comments
How about adding the SWR display like 5.1 but keeping the smaller fonts?
On the 5.1 version some of the top line data on the right side of the
screen gets clipped as well.
Sam Reaves
ARS W3OHM
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Re: Running NanoVNA on MacBook Pro
Wayne, just don¡¯t use Version 3.8 of python¡its buggy¡
I have this running fine on Catalina with v 3.7 of python.
Dana VE3DS
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On Nov 19, 2019, at 17:34, vk6eh@... wrote:
hi all, forgive me if I missed any previous post on this subject.
Is it possible to run a nanoVNA on a MacBook, any problems, how to, s/ware etc ?
thanks
Wayne VK6EH
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Re: [nanovna-f] Why are Archives visible to subscribers only?
On Sat, 23 Nov 2019 at 16:57, Oristo <ormpoa@...> wrote: I tend to be annoyed Content is available by web searches including site:
groups.io/g/nanovna-users
<> My comment was sent to nanovna-f, not nanovna-users. NanoVNA-users is open to anyone to read, but nanoVNA-f is not. -- 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: New 5,1 Firmware comments
Hi Sam,.??
I spoke to Dennis about this earlier as it's been this way for all of his larger font releases.?
Unfortunately, there is only so much room on the display and Dennis is trying to squeeze 4 traces of large font into an extremely small area.?
That is why hugen's larger font version is only 2 traces so everything fits.?
At least this version has the huge SWR display, and the bottom line isn't really that bad.....
73.... Larry
On Sat, 23 Nov 2019 at 2:19 PM, Sam Reaves<sam.reaves@...> wrote: I noticed on my unit the larger font is clipped at the bottom of the screen and at the top right.
Is there a way to change this?
Sam
W3OHM
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Re: Coax cable length influence on calibration
Hi Kurt, hi David, thank you very much for your replies!
of course, the coax cables were calibrated at the far end with SOL isolation and through. The first calibration (picture 1), directly on CH0 and CH1 connectors served as a reference without cables, where I expected the best performance. After the various calibrations were finished, the 50 ohm cal standard was placed again at the end of the coax cable connected to CH0. CH1 was terminated as well to see the dynamic range of S21. I do understand that the NanoVNA has no error correction like the VNWA. What I wanted to point out with this test is, that with a certain length of coax cables the overall performance of the NanoVNA can be improved. Like in my case by using standard RG174U with a length of 70 cm or the M17/152 coax cable with 93cm length. I didn't expect the marginal performance of the short 20 cm high quality coax cable. I fabricated those because I thought they would perform at best.
We all know, RF is a science on its own, hi!
Hope that clarifies initial misunderstandings!
Best regards
Norbert, DG1KPN
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Oristo
David J Taylor
Sam Reaves
Dr. David Kirkby, Kirkby Microwave Ltd