Re: I need help
Grazie
Inviato da iPhone
By
Paolo
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#39946
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Re: I need help
Hi, I have seen a video on Youtube…
NANOVNA analizzatore di antenne: come usarlo ( https://youtu.be/iTzKgFMUoJc )
youtu.be ( https://youtu.be/iTzKgFMUoJc )
( https://youtu.be/iTzKgFMUoJc )
Inviato
By
Paolo
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#39945
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Re: I need help
Per avere il valore zero sul diagramma di Smith (puntatore alla estrema
sinistra) devi mettere il connettore SHORT.
[email protected]> ha scritto:
By
Gabriele I4JXE
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#39944
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Re: I need help
Port 2 is 50Ω as it should be, why do you imagine that it would be 0?
[email protected]> wrote:
By
Dragan Milivojevic
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#39943
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I need help
I buyed a nanovna H 3.6. When I try to calibrate it, after the full procedure, if I set a Smith diagram and I connect THRU the two ports using the supplied cable the value is 50 ohm instead of 0. I
By
Paolo
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#39942
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Re: NANO VNA H4 , Implausible measurement results?
Hello Jon,
As you wish to use the antenna on the higher harmonics as well as 2M, I would suggest you use ferrites to create a Common Mode Choke (CMC) as noted by Roger.
I suspect (but do not know, I
By
Bob Ecclestone VK2ZRE
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#39941
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Re: NANO VNA H4 , Implausible measurement results?
Yes,a dipole will work without a balun. But it is not a dipole anymore. The outer surface of your coax shield becomes part of the antenna system. This can give inaccurate results with the VNA. In
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Jim Shorney
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#39940
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Re: Measuring Capacitors
Your first link redirects to the same url the OP posted but I got to ask:
What is your issue with the paper being hosted in Bosnia&Hertzegovina,
the paper originated there.
[email protected]>
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Dragan Milivojevic
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#39939
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Re: NANO VNA H4 , Implausible measurement results?
I suspected the 50 Ohm calibration resistor and ordered two new ones.
After recalibration and measurement, the SWR is 1.26 at 172 MHz and 1.65 at 522 MHz.
Both measurements with SOL calibrated
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hobride
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#39938
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Re: Measuring Capacitors
Other sources that are in other countries than Bosnia Hertzegovina
https://doi.org/10.7251/ELS1418029S
https://doaj.org/article/f97e342395e443358e02546e68ea0fb9
The authors have a number of other
By
Jim Lux
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#39937
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Re: NANO VNA H4 , Implausible measurement results?
The SWR for a 50 Ohm cable will depend on the feedpoint impedance at the end of the cable. The impedance will depend on the antenna dimensions, its height, and its proximity to the environment. If the
By
Ken
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#39936
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Re: NANO VNA H4 , Implausible measurement results?
You need to calibrate your coax SOL at the far end, so your readings look
like your antenna is at the vna and not some distance away.9
[email protected]> wrote:
By
Fred Moore
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#39934
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Re: NANO VNA H4 , Implausible measurement results?
Maynard and others:
You and we were most fortunate to be initiated with one of the most robust sunspot cycles of modern times in 1957!!
Same story at pre-Nano VNA KN1CJO in southern Maine. Worked
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AG6CX
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#39933
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Re: NANO VNA H4 , Implausible measurement results?
I got my Novice license in 1957 and used a single wire routed out the window and up to the brick chimney and then across the yard about 100 feet to a pole. It worked fine, with my best DX using a
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Maynard Wright, P. E., W6PAP
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#39932
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Re: Measuring Capacitors
Nice find!
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Matthew Rapaport
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#39931
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Measuring Capacitors
I ran into a research paper on measuring capacitors using a VNA that might be of interest. It analyzes capacitance and ESR accuracy for the S11 reflection, S21 series-through, and S21 shunt-through
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Brian Beezley
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#39930
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Re: NANO VNA H4 , Implausible measurement results?
Have you turned on the VNA's Smith chart? At what frequencies thru your sweep does the trace cross the chart's center (no reactance) line? Those are your antenna's resonant frequencies. The one
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Matthew Rapaport
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#39929
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Re: NANO VNA H4 , Implausible measurement results?
Joe,
I got licensed a decade after you and did not have a chance to use a balun
or 50 ohms coax then. My 40 and 80m dipoles were fed by 75 ohms TV cable. I
did not have an SWR meter either. Still I
By
Jon
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#39928
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Re: NANO VNA H4 , Implausible measurement results?
Yup!
The Balun Craze is a new Generation thing. Got licensed in 1975, Never ever heard of a Balun.
All my dipoles were direct feed.
Only till recently has the myth of a dipole without a balun will not
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Joe WB9SBD
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#39927
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Re: NANO VNA H4 , Implausible measurement results?
It's measuring the 3rd harmonic which shows a nice low SWR. how far below 172 Mhz did you start your scan?
Joe WB9SBD
By
Joe WB9SBD
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#39926
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