When I have this problem it¡¯s usually because I¡¯m getting RF coming back on the shield, I put a couple of clamp on fairite chokes on or coil the coax and I get good readings again. Just an idea.
73 Bill N7OQ
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On Jun 6, 2022, at 14:45, W0LEV <davearea51a@...> wrote:
?This has been addressed a number of times in this group. If you cal
without the USB cable connected and then connect it for a measurement of
your unknown, this is quite expected. The case of the VNA is "extended" by
the presence of the USB cable and interacts with the unknown, especially if
it is a radiating structure.
Dave - W0LEV
On Mon, Jun 6, 2022 at 12:19 PM Stefan <spommere@...> wrote:
Hi,
I have a MFJ-259B antenna analyzer and now also a NanoVNA-H, along with
the NanoSaver App.
I get inconsistent VSWR readings with both devices:
MFJ: 1.8
NanoVNA not connected to laptop via USB-C: 2.7
NanoVNA connected to laptop via USB-C: 1.1
The VSWR reading on the NanoVNA literally goes from 1.1 to 2.7 when I
unplug the USB-C cable from the NanoVNA.
I went through call calibration steps at least a half dozen times on the
NanoVNA for 50kHz to 900MHz, and for the 40m band (7.0 MHZ - 7.3 MHZ).
Any suggestions as to what value I should actually trust ?
I wonder if I need to calibrate the NanoVNA through the Saver app
separately; based on what I've gathered, it should not be necessary.
Thanks for any advice.
--
*Dave - W?LEV*
*Just Let Darwin Work*
--
Dave - W?LEV
