Re: Newbie URGENt help needed!


Peter Ide-Kostic <on7yi.pik973@...>
 

Hello,
Looks like a cable/connector problem on the second vna, it does nor seems
to me normal
I would start by using the very same cables/connectors on both vna and/or
ewapping cables to see what happens.
It is also possible the sma connector on the second vna is faulty

On Tue, 5 May 2020, 12:49 , <davebullockmbe@...> wrote:

Hi everyone,
I need help on what is 'The Norm' regarding my nanoVNA display.
Due to an ordering 'glitch' my ebay order somehow got changed from one to
two nanoVNA's.
So now being the owner of two devices i made the stupid mistake of
comparing the two machines.

I have found (look at the attached picture in picture) that for all
positions of calibration ie. SHORT OPEN and LOAD that one nanoVNA produces
a stable and clean marker (inset),
whereas the second machine produces the marker but with a multitude
(nest) of tiny vectors around the calibration point.
I am in conversation with the Ebay seller about this difference.
So my question to you experts is:-

Is one of the nanoVNA's faulty and if so which one?
I would have imagined that the'clean' display was correct and that the
display with the 'noisy' nest of vectors is faulty.
However:- does this noise indicate that this machine has high 'gain', and
it's the stable looking one that is LOW gain and faulty?
As I don't have a third nanoVNA to compare against, I desperately need
expert advice.
PLEASE HELP.
Thanks in anticipation....
Dave



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