Re: Calibration Procedure
Where did you download the calibration procedure from? The downloaded manual I have reads like aChinese Fortune Cookie. It makes no sense and gives me a headache to try to figure it out.
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Terry Nixon
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#4573
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Re: A way to improve the accuracy of the calibration of a male SMA connector
The problem here is that we don't know parameters of cal-kit which is supplied with nanoVNA... So, just adding ability to setup cal-kit parameters won't help. Because we're needs to know what
By
QRP RX
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#4572
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Re: reference plane
you're needs to perform RESET before calibration. If you don't do that, you will get strange results.
By
QRP RX
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#4571
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Re: Measuring Q
if your antenna has VSWR other than 1:1 at resonant frequency, it means that you have poor impedance match with your antenna. Before measure Q factor, you're needs to improve impedance match between
By
QRP RX
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#4570
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Re: reference plane
Yes, but NanoVNA-saver doesn¡¯t give one a *stand-alone, self contained unit* like an Agilent FieldFox. Personally I don¡¯t want to have to use an external computer with the NanoVNA. I obtained a
By
Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
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#4569
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Re: Measuring Q
In short, if you have VSWR not equal to 1.00 at resonant frequency, it means that you have poor impedance match between signal source and antenna.
By
QRP RX
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#4568
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Re: Measuring Q
minimum VSWR at antenna resonance is always 1:1. Because you should match your feeding line with antenna impedance at resonant frequency. If you write your antenna impedance as R+jX, and your feeding
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QRP RX
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#4567
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Re: Measuring Q
Yes, makes sense. The condition for this Q equation is unique. Requires a perfectly matched antenna. This would be analogous to the case of an R-L-C network perfectly matched to its measurement
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alan victor
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#4566
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Re: Measuring Q
You can find it school book at physics section about LC circuit. That is basic thing in the radio: Q = Fc / BW If you use fractional bandwidth BWF ( fractional bandwidth = bandwidth / Fc ) it turns
By
QRP RX
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#4565
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Re: reference plane
Hi David I think you should read my response to this question. You negative conclusion is not valid. Pragmatic solution are still useable and in addition using the NanoVNA-saver you got it all to
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Kurt Poulsen
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#4564
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Re: Measuring Q
Alan, thank you very much for mentioning the HP app note! I've taken a look at its figure 8-13 as well as another S11 plot of a resonant circuit, and I now believe that the earlier-mentioned SWR
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Jeff Anderson
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#4563
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Re: A way to improve the accuracy of the calibration of a male SMA connector
wrote: Kurt is right. Moving the reference plane in software is going to be better than doing the trick I suggested. I don¡¯t know why I didn¡¯t think of this - I regularly use port extensions to
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Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
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#4562
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Re: reference plane
Yes, Kurt is right, you can compensate this in software by moving the reference plane. It is far from ideal - it would be better if the data on the calibration standards could be properly entered. --
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Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
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#4561
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A way to improve the accuracy of the calibration of a male SMA connector
Ken Boswoth reported error in calibrating on a cable with a male SMA on it. Here¡¯s a way to improve on that, despite the fact that the firmware doesn¡¯t allow one to do it properly. Here are few
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Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
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#4560
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Re: reference plane
Hi Ken Shure you can calibrate at the end of cable. You have noted when CH0 left open you see an open after a full calibration with Short nothing as open and laod. It has been compensated internally
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Kurt Poulsen
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#4559
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Re: reference plane
[email protected]> wrote: But it is currently *totally impossible to get a valid calibration on a cable with a male SMA on the end. *The firmware doesn¡¯t permit one to enter any characteristics
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Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
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#4558
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Re: reference plane
Ken, As delivered, the NanoVNA default calibration, Location 0, is apparently set up with the S11 reference plane at the on-board connector. You can run another calibration at the end of your cable
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John Gord
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#4557
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Re: reference plane
drkirkby@...> wrote: I should have been clearer here. There are two issues 1) The firmware prevents you getting a proper calibration at the reference plane. 2) Even if the firmware
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Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
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#4556
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Re: reference plane
You are doing nothing wrong - it is a limitation of the firmware in the NanoVNA. The calibration standards supplied are male. When you add a female-female thru on, you are adding a bit of transission
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Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
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#4555
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Potential for the female-female thru to damaged other connectors.
I reported a few days ago that I had measured the return loss of one of the female-female thrus supplied with my NanoVNAs when open at one end. Measurements were made with an HP 8720D VNA with an HP
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Dr. David Kirkby from Kirkby Microwave Ltd <drkirkby@...>
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#4554
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