¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
  1. Nanovna-Users
  2. Topics

sensitivity (instability)

[email protected]
 

Bonjour ,Hi
i have been searching in old topics what i am experiencing and i did not find anything.
So did you ever notice that the reading of S11 is pertubated if you touch or not the nanovna.
even if the nanovna is on the table and my hand get close to the vna there is fluctuation in the reading..

so what do you do to make shure it is ok?
Richard.
this happen whit naovna ,nanovna -h and nanovna -F as well but less for the last one
 

Somehow got the wrong photo.
Here is the correct one:
/g/nanovna-users/photo/0/416?p=Created,,,20,2,400,0
and
/g/nanovna-users/photo/0/417?p=Created,,,20,2,400,0

...Larry

On Wed, Nov 20, 2019 at 08:20 AM, Larry Rothman wrote:
Hi Richard,
This has been discussed a few times in the past month or so.The issue is that
the NanoVNA itself is not grounded so when you approach it, the near field
area changes.
A couple of forum members have mounted their Nanos on plastic boards they can
hold in order to minimise any measurement affects.
Have a look here: /g/nanovna-users/photo/0/416
On Wednesday, November 20, 2019, 7:52:02 a.m. GMT-5, ve2zvz via Groups.Io
<ve2zvz@...> wrote:

Bonjour ,Hi
i have been searching in old topics what i am experiencing and i did not find
anything.
So did you ever notice that the reading of S11 is pertubated if you touch or
not the nanovna.
even if the nanovna is on the table and my hand get close to the vna there is
fluctuation in the reading..

so what do you do to make shure it is ok?
Richard.
this happen whit naovna ,nanovna -h and nanovna -F as well but less for the
last one
 

What are you measuring, an antenna?
 

So did you ever notice that the reading of S11 is pertubated if you touch or
not the nanovna. even if the nanovna is on the table
and my hand get close to the vna there is fluctuation in the reading
My unshielded "worse" clone is quite immune to proximity effects.
In fact, the only time it became a problem was an SMA cable gone defective,
presumably a poor crimp between connector and cable braid
[email protected]
 

Yes
 

I assume the YES is the answer to an antenna is under test. if the antenna physical dimension is not much larger than the vna and not current de coupled from the port, than the vna is part of the measurement system under test. The port Z will change as a consequence.
[email protected]
 

Tnx Alan
This morning I made new cables with rg142 and I think the double sheild helped a lot...
once again tnx and I am getting happier more I discover those little wonders!
Richard

1 - 7 of 7