On Mon, 16 Dec 2019 at 05:33, <hugen@...> wrote:
There are more than 5 clones of NanoVNA-H at present, some are with
shielding cases.
If you could produce a set of specifications, in a *format* used by
Keysight, then people with the right equipment could compare the
performance of one NanoVNA-H against and the specifications, and return
¡°clones¡± if they have an inferior specification.
I have seen meaningless terms like ¡°S11 directivity¡±.
I am *not* saying that a $50 VNA should have the same performance as a
$100,000 VNA. If the system dynamic range is 50 dB lower, that¡¯s fine.
Let¡¯s be honest, it is really part of the Chinese culture to counterfeit
devices. The problem exists in much of Asia. You were once yourself of
breaching the GPL.
Have you ever reversed-engineered a product to produce a clone?
But due to their wrong assembling, the performance decreases.
With a well written specification, following closely the format of a major
VNA manufacturer like Keysight, some users would be in a position to
determine if the specifications are poorer. Then poor sellers would soon
get a bad reputation.
Assembling the shielding case is to isolate effectively, but if they
connect the shielding case of CH0 with CH1, it will sharply decreases the
performance.
These problems would be much reduced if we had a decent specification to
compare against.
Although some clones are with good performance, we could only make
judgement after testing. I am quite annoyed, because some irresponsible
agents sell inferior clones which marks as my version, it is a serious
cheating.
Just like you *were* doing with the GPL! Seriously cheating!
I get the feeling that there are a
I have updated NanoVNA-H to version 3.4 after I received much feedback from
the community. It is under assembling&testing at present. It works well
till 1.5GHz in the present testing. Meanwhile, I changed the power chip and
the battery to 650mAH which further decreases the noise from the usb
charging. In addition, it could work 4 hours after these changes. If
everything goes well, the new version will come to the market on Dec.20.
With what size and resolution of screen? The NanoVNA is very nice, but for
many users, myself included, the screen size is its biggest problem.
You could buy from Maggie through this link:
hugen
I am sure you will find a lot more buyers from Europe and the USA if you
sold via eBay. Many small Chinese companies sell on eBay.
Dave.
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
Telephone 01621-680100./ +44 1621 680100
Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom
Dr. David Kirkby, Kirkby Microwave Ltd