Hello, everyone

Yesterday I received NanoVNA V2plus4 from DHL which I was looking forward to. Unfortunately, when I measured the 10.7 MHz monolithic crystal filter S21, there was an abnormality in the waveform, so I would like to report it. Attach the same filter results as measured with V2_2 and V2plus4. The waveform of V2plus4 is jagged and not smooth. This does not happen with V2_2, so I think it is the problem of the V2plus4 which I purchased. This phenomenon appears to be frequency dependent and did not occur with the 20 MHz crystal S21. I tried making and replacing the latest version of the git -20201124 firmware, but it was still the same. Waveform errors are the same for stand-alone operation or controlled by NanoVNA-App v 1.1.160 via USB.
I hope this problem will be resolved.
--
TENKO

Calibrate and measure your xtal filter with x5 average.. Then calibration has
less "noise" and also the measurment at the end is more exact

Greetz sigi dg9bfc



Am 28.11.2020 13:53 schrieb Tenko46T <nasa46vb@gmail.com>:

> Hello, everyone

>

>
>

> Yesterday I received NanoVNA V2plus4 from DHL which I was looking forward
to. Unfortunately, when I measured the 10.7 MHz monolithic crystal filter S21,
there was an abnormality in the waveform, so I would like to report it. Attach
the same filter results as measured with V2_2 and V2plus4. The waveform of
V2plus4 is jagged and not smooth. This does not happen with V2_2, so I think
it is the problem of the V2plus4 which I purchased. This phenomenon appears to
be frequency dependent and did not occur with the 20 MHz crystal S21. I tried
making and replacing the latest version of the git -20201124 firmware, but it
was still the same. Waveform errors are the same for stand-alone operation or
controlled by NanoVNA-App v 1.1.160 via USB.

>

> I hope this problem will be resolved.

>

> \--
> TENKO



_._,_._,_

* * *

​Thank you for your reply.

​As you told me, I calibrated and measured again using x5 averaging operations.

​Unfortunately, the results remained the same jagged and no improvement.

​As a separate experiment, I tried smoothing the trace, but it appears to improve the waveform smoothly but does not provide a fundamental solution because it reduces the fidelity of detail. ​

By the way, this thread is a double post to make up for missing the image attachment in the previous article. ​I am very sorry, but I would like to close this thread.
--
TENKO