As of 2022 there are many badly performing clones on the market. V2/3GHz NanoVNA uses parts like ADF4350 and AD8342 which are costly and clones have been cutting costs by using salvaged or reject parts.
See official store and look for V2 Plus4/V2 Plus4 Pro versions only to avoid getting a bad clone. We have stopped selling V2.2 versions since October 2020, so all V2 hardware that are not Plus or Plus4 are not made by us and we can not guarantee performance.
An addition at the beginning and a few minor 'fixes'. Going to sleep last
night I kept mulling over changes I wanted to make. See attachment.
Dave - WØLEV
add a fourth row of values .. measure the common mode attenuation not
only the trough loss!!
how to do that?? ... say you have a coax choke ... then connect the
shields to the hot ends of your test jig ...
if you have a two wire (twisted pair) then connect only ONE of the two
to your test jig (does not matter if the "white" or "black" wire used
cause they should be identical)
see drawing (just a rough sketch to give you the idea)
for trough loss you connect both wires on input and output of your balun
for common mode surpression only connect ONE on input and output
(normally shield used if you have a coax choke)
greetz sigi dg9bfc
Am 30.01.2021 um 17:30 schrieb David Eckhardt:
It seems that you missed a week or so of messages.
On Sat, 30 Jan 2021 at 18:57, Siegfried Jackstien <
siegfried.jackstien@freenet.de> wrote:
no ... i read them all for sure ...
a good choke not only has good match on input and output and low trough
loss ... a good choke also has a high isolation (common mode
surpression) ... and i miss them in the table
greetz sigi dg9bfc
Am 30.01.2021 um 19:15 schrieb Dragan Milivojevic:
The man is redoing the measurements that he did on his HP VNA ...
On Sat, 30 Jan 2021 at 20:26, Siegfried Jackstien <
siegfried.jackstien@freenet.de> wrote:
Siegfried:
That is coming. The procedure is a bit different, although the beginning
is identical. I have built a fixture to accommodate shields being
connected, but only the windings are measured as you point out. I just ran
out of steam, yesterday.
Dave - W ØLEV
On Sat, Jan 30, 2021 at 5:57 PM Siegfried Jackstien <
siegfried.jackstien@freenet.de> wrote:
> add a fourth row of values .. measure the common mode attenuation not only
> the trough loss!!
>
> how to do that?? ... say you have a coax choke ... then connect the
> shields to the hot ends of your test jig ...
>
> if you have a two wire (twisted pair) then connect only ONE of the two to
> your test jig (does not matter if the "white" or "black" wire used cause
> they should be identical)
>
> see drawing (just a rough sketch to give you the idea)
>
> for trough loss you connect both wires on input and output of your balun
>
> for common mode surpression only connect ONE on input and output (normally
> shield used if you have a coax choke)
>
> greetz sigi dg9bfc
>
>
> Am 30.01.2021 um 17:30 schrieb David Eckhardt:
>
> An addition at the beginning and a few minor 'fixes'. Going to sleep last
> night I kept mulling over changes I wanted to make. See attachment.
>
> Dave - WØLEV
>
>
>
>
>
--
*Dave - WØLEV*
*Just Let Darwin Work*
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