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Isolate any part of the coaxial


Pascal CASTRATARO 2021/03/14 06:34

How do you isolate any part of the coaxial cable? I'm looking for specific examples
(NanoVNA H4)

Leif M 2021/03/15 13:38

What do you mean by isolating. If you have a length of coaxial line between your VNA and your load(that what you want to measure), you have to give a negative delay reading to the VNA. In my opinion it is easiest with PC software.

Pascal CASTRATARO 2021/03/16 03:45

Thank you. Yes, That's what I want to do, isolate from the VNA, 15 meters
of coaxial without needing to ride on the roof. The factor velocity is 86.
But I do not know how to ...

Le lun. 15 mars 2021 à 21:45, Leif M <leif.michaelsson@gmail.com> a écrit :

Pascal CASTRATARO 2021/03/15 19:47

Thank you. Yes, That's what I want to do, isolate from the VNA, 15 meters of coaxial without needing to ride on the roof. The factor velocity is 86. But I do not know how to ...

Thorsten DL9SEC 2021/03/15 21:27

Be aware, that you have to calibrate the VNA to the end of the cable (and ride the roof), otherwise you will only see a lot of circles and a good matching (the damping of 15m+15m will fool you into believing to have a good S11)...

Regards, Thorsten

Pascal CASTRATARO 2021/03/16 15:47

This is my problem, I cannot climb on the roof, I am too old. Since I know
the length of my coax, can't I undo it from the VNA?

Le mar. 16 mars 2021 à 05:27, Thorsten DL9SEC <thorsten.godau@gmail.com> a
écrit :

Leif M 2021/03/16 11:15

The problem is propably that you cannot tell exactly the needed delay. But here is one place you should put the delay (offset delay) as a negative number. I have several NanoVnas and their PC softwares so I do not know if this program what you have.

Or

Pascal CASTRATARO 2021/03/17 00:00

Don't worry. I'll find it. Thank you

Le mar. 16 mars 2021 à 19:15, Leif M <leif.michaelsson@gmail.com> a écrit :

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